Coordinating concrete delivery and placement

Abstract

To provide a method for monitoring curing time conditions of a plurality of concrete placements.SOLUTION: A method includes: a step of traveling across a plurality of concrete placement locations at a work site an aerial drone having a sensor for monitoring the surface of the concrete placement location for hydration over time by scanning a topography of the placed concrete to obtain a hydration-indicating data signal; a step of comparing the data signal to a previously stored data signal to obtain a curing time value that correlates with hydration data obtained from the sensor; and a step of generating a picture or a map of the plurality of concrete placement locations along with the curing time value or a proposed sequence priority based thereon, thereby providing a placement instruction suitable for sequential processing such as for (a) initiating finishing, (b) completing finishing, and (c) removing a framework or a model from the concrete.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] Inventors: Nathan TREGGER, Mark ROBERTS, Jason STRAKA, Elise BERODIER, Greg AUSTIN, Robert HOOPES.

[0002] The present invention relates to concrete construction processes and systems, and more particularly to coordinating set time values ​​or ranges of values, such as workability or compressive strength windows, of a concrete load delivered and placed at a job site. [Background technology]

[0003] Batching a concrete mix load typically involves introducing cement, aggregate, water, and optional chemical admixtures into a rotary mixer drum of a ready-mix truck, where the components are mixed together uniformly, and transported to a job site where the concrete mix is ​​placed.

[0004] The terms "location" or "pouring" may be used hereinafter to refer to various means of transporting plastic concrete from a truck drum to its final placement at a job site, including discharging the concrete from a drum onto a chute where it can flow or be forced into a space or framework for a slab, road, foundation, wall, or other application, pumping the concrete to a location within a high rise building above ground level, spraying the concrete onto a surface such as a foundation, wall, or tunnel surface, or depositing one concrete mass onto a previously deposited concrete mass, such as in a 3D printing process.

[0005] For example, when concrete is used to create horizontal slabs, floors, decks, pavements, or roads, it has a relatively narrow period or window in which it can be "finished." Finishing involves various steps such as planing and smoothing (troweling) the surface to ensure its durability. A construction site supervisor (or manager) will want a sense of the "initial set time," or in other words, to predict the moment when the poured concrete first develops strength such that it is workable (i.e., capable of being smoothed or moved into place) and the surfacing process can begin. The supervisor will also want to have a sense of the "final set time," or the moment when the concrete loses workability and can no longer be finished. This is especially true when the supervisor does not have a construction crew for each poured concrete load and must operate limited resources within a short time interval.

[0006] The determination of whether poured concrete can be finished (smoothed) is often made by judging the "water sheen" of the concrete surface, but this test is subjective and often perverse by the need to finish quickly. Dust problems, flaky surface defects, and large cracks make it difficult to determine when the concrete surface is ready to be finished. The usual "footprint" test to determine initial or final set time is subjective and prone to error.

[0007] When concrete is used in vertical applications such as walls, columns, or support structures (e.g., high-rise buildings), supervisory concerns may focus on various aspects of curing time: when does the concrete begin to develop internal cohesion, ultimately leading to increased stiffness and ultimate hardness? Understanding when the concrete begins to gain compressive strength can help the applicator better understand the appropriate rate at which the concrete can be pumped or poured to avoid bursting of the framework. Understanding when the concrete begins to gain compressive strength can enable the supervisor to determine how quickly the framework can be removed or how quickly the next concrete portion can be poured on top of the previously poured concrete portion. Thus, the supervisor may want to better understand the nature of the early set time as well as the later set time (e.g., the compressive strength of concrete 1, 3, 7, or 28 days after batching).

[0008] The present invention focuses on the determination of one or more set time values ​​or ranges of values, such as an initial set time, a final set time, and / or two or more set time values, which may include the start and / or end of the workability / finishability window for plastic (workable) concrete, which may also include strength values ​​for hardened (non-workable) concrete, such as compressive strength at 4 hours, or 1, 3, 7, or 28 days, or other ages.

[0009] A contractor on a building site may want to consider a single set time value, such as a final set time (where the concrete must be finished before it is allowed to harden), or, as another example, may want to consider a range of set time values ​​that include both an initial set time (after which finishing can begin) and a final set time (before finishing must be completed).

[0010] In FIG. 1, we illustrate a common problem using three example timelines representing three delivery trucks (designated 10, 12, and 14) carrying concrete loads in mixer drums. Each load has a different hydration behavior. Each load has a batch time (B) that begins at the batch plant and a different pour time (P) when the load is discharged at the job site. As shown by the dotted rectangles, the problem is caused by different set time values ​​that define different time spans or ranges, e.g., different finishing start times (designated Fs) and different finishing completion times (designated Fc). As shown in FIG. 1, the concrete poured from trucks 10 and 14 have similar pour (P) times. The finishing crew can finish poured load 10 before working on poured load 14 because Fc of load 10 ends before Fs of load 14 begins. However, load 12 has a later pour time and finishing start time (Fs) compared to the start time of load 14. Load 12 also has a finishing completion time (Fc) that occurs early compared to the finishing time of load 14. Thus, the uncoordinated set time behavior of concrete pours greatly complicates the finishing process at the job site.

[0011] The concrete industry attempts to organize concrete delivery by batch loading trucks at set intervals (e.g., every 15 minutes), but the basic assumption that trucks will arrive at similarly spaced intervals at the job site is often difficult. For example, in moving from the batch plant (B) to the pouring site (P), trucks may be delayed by traffic and job site congestion, pump failures at the site, admixture dosing errors, temperature changes that affect the hydration of concrete at the job site, and other issues. Inconsistencies in the concrete mix, such as different batch weights and mix designs (e.g., loads may contain return concrete), can affect the hydration behavior and cause variations in set time values ​​(e.g., Fs, Fc).

[0012] Uncontrolled set time values ​​or ranges of values ​​in delivered concrete can result in costly and time-consuming problems, such as sections of concrete that have to be removed and replaced because they did not finish within the applicable time. Summary of the Invention

[0013] In overcoming the above-mentioned problems, the present invention provides a method for delivering concrete that includes adjusting one or more assigned set time values ​​or ranges of values ​​of a concrete mix load being delivered to a job site, preferably based on an evaluation of concrete previously delivered and placed at the job site, allowing the delivered concrete to have an adjusted set time value or range of values, thereby allowing the properties of the concrete to be controlled.

[0014] As shown in FIG. 2, three concrete loads (B) are delivered by truck (16, 18, 20) to a job site (P) where they are placed, according to an exemplary embodiment of the present invention. In this example, the rheology and hydration rate behavior of the concrete mix is ​​monitored and the range of post-placement setting time values ​​is adjusted to ensure that they do not overlap. For purposes of simplifying this illustration, the finishing start times (Fs) and finishing completion times (Fc) of the three poured concrete loads 16 / 18 / 20 are shown as not overlapping, although there may be some overlap (as some of the finishing crew may begin moving from one section of poured concrete to work on the next section). For example, if only a minimum number of crew members are nearby to finish the placed concrete, the Fs and Fc time events may be spaced far enough apart to allow the crew to finish each poured section (e.g., 16 or 18) before proceeding to the next poured section (e.g., 18 or 20). It is also possible that the cure time value ranges may overlap slightly, such as when a supervisor is moving some of the finishing crew from one poured concrete section to another while completing necessary finishes before curing, but the goal is to avoid multiple concrete loads with matching cure times (e.g., 12 / 14 in Figure 1) when there are not enough crews to complete the finishing phase.

[0015] Thus, the present invention's concept of adjusting set time values ​​or value ranges begins with the use of an automated concrete rheology (e.g., slump) management system for individual ready mixed concrete delivery trucks, the system being controlled by a processor that allows set time values ​​(e.g., initial set time) or value ranges (e.g., initial and final set time values, and / or strength levels) to be input or calculated (e.g., by a processor of a slump monitoring system mounted on the concrete delivery truck).

[0016] The present invention also allows for adjustment of the initial set time based on concrete rheology data, such as from a site supervisor, or based on information from other concrete delivery trucks monitoring various concrete loads being delivered to the job site, or perhaps based on sensor data obtained from sensors placed above or on the surface of or embedded within the placed concrete (or a combination thereof).

[0017] For purposes of this invention, the concept of a "setting time value or range of values" can refer to any number of activities including (a) the start of finishing, (b) the completion of finishing, (c) the removal of the framework or form from the concrete (i.e., after hardening), (d) the allowing of foot or vehicular traffic over the concrete, (e) the pouring of more concrete on top of the poured concrete, or (f) other pouring site activities such as prestressing concrete mechanism adjustments. Setting time values ​​are presumed to reflect the moment the concrete load is loaded or mixed at the batching plant or is reconditioned (in case of return from a different job site or from a different pouring location at the same job site) and new concrete is batched on top of the returned concrete load. In other words, setting time values ​​or ranges of values ​​can refer to any of a number of placement time time events depending on the application. or even post-placement properties such as concrete compressive strength at various ages.

[0018] Thus, an exemplary method for coordinating delivery of concrete of the present invention includes: (A) providing at least two delivery trucks, each having a mixer drum containing a concrete load and a processor controlled system for monitoring the rheology (e.g., slump, slump flow, yield stress) and at least one set time value or range of values ​​(e.g., initial set time, final set time, compressive strength or a mixture of these values) of the concrete load in the drum, wherein the processor: (i) accessing at least one stored set time value or range of values ​​assigned to a load of concrete in a mixer drum for delivery to a job site; (ii) calculating at least one current set time value or range of values ​​for the load based on the monitored hydration over time; (iii) comparing at least one stored cure time value or range of values ​​with at least one calculated current cure time value or range of values; and (B) adjusting a current set time value(s) or range(s) of values ​​by introducing a set accelerator, set retarder, or mixture thereof into at least one of the at least two delivery truck concrete loads to perform or modify a sequential placement, finishing, demolding, framing removal, or compressive strength stage of the concrete loads poured from the at least two delivery trucks; Includes.

[0019] In further exemplary embodiments, the stored or current set time values ​​may include an initial set time (after which finishing may begin), a final set time (before which finishing must be completed), and perhaps even a range of set time values ​​(e.g., defined by both an initial set time and a final set time), and may also include other placement events (e.g., development of strength of poured concrete at one or more concrete ages, e.g., 4 hours, 4 days, or other ages from time of batching). Again, there may be some overlap in terms of workability windows (e.g., the end time of a previous pour may occur after the start time of a subsequent pour). The stored or current set time values ​​may be established by monitoring temperature changes of the concrete over time, preferably at a given concrete slump, using, for example, a commercially available slump monitoring system mounted on a delivery truck. The inventors envision that adjustment of the concrete load's current set time value or range of values ​​may be accomplished by monitoring dosages of set accelerators, set retarders, or mixtures thereof using such commercially available monitoring systems (e.g., VERIFI® Monitoring Systems, GCP Applied Technologies Inc., Cambridge, Massachusetts). Additionally, in a further exemplary embodiment, the present invention facilitates rerouting of a full or partial delivery truck load from a first job site to another job site for delivery of the full or partial load, such that the first job site may not be the final "pour site."

[0020] In further exemplary embodiments, monitoring the hydration of each concrete load over time may be done in a number of ways: For example, the temperature of the concrete load may be measured over time and taken into account along with the batch volume (including the load size at the batch plant and any additional water or admixtures added at any time, plus the age of the concrete).

[0021] The present invention also provides a method for monitoring the set time condition of a plurality of concrete placements. ,The method is as follows: moving at least one aerial drone having at least one sensor (e.g., a sensor selected from optical, infrared, acoustic, radio wave, microwave, electrical resistivity, electrical capacitance, and ultrasonic sensors) for monitoring the hydration of the placed concrete over time at a job site over a plurality of concrete placement locations to obtain a data signal indicative of hydration; comparing the obtained data signal to previously stored data signals to obtain a set time value or range of values ​​that correlates with the hydration data obtained from the at least one sensor over time; generating a pictorial or map of multiple concrete placement locations along with set time values ​​or ranges of values, or suggested sequence priorities based on set time values ​​or ranges of values, thereby providing placement instructions suitable for sequential processing for (a) starting finishing, (b) completing finishing, (c) removing the framework or form from the concrete, (d) allowing foot or vehicle traffic over the concrete, (e) releasing the tensioned cable from the jack (e.g., for use in prestressed concrete applications), (f) anchoring or grouting the cable after tensioning (e.g., for post-tensioned concrete), or (g) pouring more concrete on top of the previously poured concrete; Includes.

[0022] Further advantages and features of the present invention are described in greater detail below. [Brief description of the drawings]

[0023] An appreciation of the advantages and features of the present invention may be more readily appreciated when considered in conjunction with the following written description of the preferred embodiments, and in conjunction with the drawings, in which: [Figure 1]FIG. 1 is an exemplary timeline diagram of three ready-mix delivery trucks with uncontrolled hydration concrete loads, as described in the Background section above. [Diagram 2] FIG. 2 is an exemplary timeline diagram of a ready-mix delivery truck having a concrete load in which the hydration state is adjusted using an exemplary method of the present invention, as described in the Background section above. [Diagram 3] FIG. 1 is a block diagram illustrating the use of a UAV (aerial drone with sensors) to monitor concrete curing conditions at a job site, according to certain embodiments of the present invention. [Figure 4] FIG. 1 is a graphical representation of a slab measured at two injection locations marked by its moisture content (i.e., MA and MB) at a particular time t=20 min according to a particular embodiment of the present invention. [Diagram 5] 1 is a plot of normalized moisture values ​​measured over time for each section A and B, according to certain embodiments, where markers "O" and "X" represent UAV measurements, the solid line represents the fitted logistic curve, the dotted line represents future predictions, and the shaded area is a plot showing the optimal finishing window. [Figure 6] 11 is a plot of normalized moisture value including second derivative illustrating that local extremes may be associated with optimal finishing windows, in accordance with certain embodiments. [Figure 7a] 1 is a plot of hypothetical measurements collected using a UAV (drone with sensors) 10 minutes after a reference time point, according to certain embodiments. [Figure 7b] 11 is another plot of hypothetical measurements collected via a UAV 30 minutes after a reference time point, in accordance with certain embodiments. [Figure 7c] 11 is another plot of hypothetical measurements collected via a UAV 60 minutes after a reference time point, in accordance with certain embodiments. [Figure 7d]13 is another plot of hypothetical measurements collected via a UAV at a time 80 minutes after the reference time point, in accordance with certain embodiments. [Figure 8] 13 is a plot of sensor data for two concrete placement areas over time along with a predictive model fit for each set of data. [Figure 9] 1 is a schematic diagram of a concrete delivery truck route, according to certain embodiments. [Figure 10] 1 is a plot of experimental results of various optical measurements of the surface of a poured concrete slab over time in accordance with certain embodiments. [Figure 11] FIG. 13 is a graphical illustration of median intensity of color (in terms of grayscale) of poured concrete segments over time, which may be correlated with hardening properties of concrete, in accordance with certain embodiments. [Figure 12] FIG. 13 is a graphical illustration of grey level contrast over time for a particular segment of a poured concrete slab that may be used to suggest a set time value or characteristic, according to certain embodiments. [Figure 13] 1 is a graphical illustration of an infrared (IR) sensor response to wavelengths between 760 and 1100 nm reflected by a poured concrete segment over time, according to certain embodiments. [Figure 14] FIG. 1 is a graphical illustration of actual setting time values ​​(plotted along the horizontal axis) compared to predicted setting time values ​​(plotted along the vertical axis) derived from a database of concrete performance attributes and concrete physical properties such as mix design, batch weight, or water / cement ratio. [Figure 15] FIG. 1 is a graphical illustration of actual setting time values ​​(plotted along the horizontal axis) compared to predicted setting time values ​​(plotted along the vertical axis) derived from a database of concrete performance attributes and another database of concrete physical properties such as mix design, batch weight, or water / cement ratio. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] As used herein, various devices and components may be described as "comprise" other components. As used herein, the terms "comprise(s)," "include(s)," "having," "has," "can," "contain(s)," and variations thereof, are intended to be open-ended transitional phrases, terms, or words that do not exclude the possibility of additional components.

[0025] The term "concrete" typically refers to a mixture of cement (often with supplementary cementitious materials such as limestone, fly ash, granulated blast furnace slag, and other pozzolanic materials) and aggregates (e.g., fine aggregates such as sand, coarse aggregates such as gravel), and optionally one or more chemical admixtures (e.g., plasticizers to enhance workability, set accelerators, set retarders, air entrainers, air suppressants, plastic shrinkage reducing admixtures, corrosion inhibitors (for rebar) to modify the concrete in its plastic or hardened state. Concrete is considered to be a hydratable material in that the addition of water to the cement and aggregate mixture initiates the hardening reaction.

[0026] The term "cement" includes hydratable cements such as Portland cement, which are produced by grinding clinker consisting of hydraulic calcium silicates, aluminates, and aluminoferrites, as well as one or more forms of calcium sulfate (e.g., gypsum) as a grinding additive. Typically, Portland cement is combined and provided as a blend with one or more auxiliary cementitious materials, such as fly ash, granulated blast furnace slag, limestone, natural pozzolans, or mixtures thereof, all of which bind aggregates together to produce concrete. Thus, "cement" and "cement binder" may also include auxiliary cementitious materials interground with Portland cement during production.

[0027] The term "concrete delivery truck(s)", also known as ready mixed concrete truck(s), means and refers to a vehicle having a rotatable mixer drum with a non-vertical axis of rotation. Such mixer drums typically have at least one blade or fin attached to the inner wall of the drum and arranged helically about the axis of rotation, such that rotation of the drum in one direction forces the concrete components towards the closed end of the drum (thus in a mixing or loading mode), while rotation in the opposite direction expels the material through the open end of the drum (thus in a pouring or discharging mode).

[0028] The phrase "batch time" or "batching time" is designated as "B" in Figures 1 and 2 and is used to refer to various events including, for example, (a) the time when a truck begins receiving concrete or certain mix ingredients for producing concrete (e.g., cement, aggregate, water, optional chemical admixtures) into the mixer drum; (b) the time when one or more chemical admixtures (e.g., superplasticizers, set retarders, set accelerators, or mixtures thereof) are added to the mixer drum containing the concrete or concrete ingredients; (c) the time when the materials are mixed together in the mixer drum and are determined to be uniformly mixed (e.g., which may be determined by ensuring that slump sensor readings are relatively constant over a given number of drum revolutions); or (d) the time when a truck exits the batch plant.

[0029] For example, a particular batch plant may typically specify the time that components are introduced into a mixer drum, which may be documented or stored in an electronic or paper batch ticket, and when an electronic batch ticket is issued, the time may be transmitted to a dispatch center and / or an automated slump monitoring system in the delivery truck that is loaded with concrete, which may be used to determine a set time value or range of values ​​for a particular load.

[0030] The term "pouring" means or refers to when a full or partial load of concrete is poured, sprayed, or deposited at a job site into a final location. Multiple pours may occur. For example, an initial pour may be made to check the concrete properties. Adjustments may be made to the concrete that can continue to be poured. Partial pours can occur if a receptacle for receiving the concrete is full or if the load is rejected after checking the concrete properties. In these cases, the concrete can be returned to the batch plant or to another location on the same or a different job site so that the remaining concrete can be used.

[0031] For purposes of Figures 1 and 2, "pouring" is designated "P" and refers to the moment when a full or partial load of concrete is discharged from a delivery truck at a job site. A single truck can have multiple pours. For example, an initial pour can be made to allow the properties of the concrete to be inspected and adjustments to be made to the concrete, so that the remaining portion of a given load can be discharged from the truck into place.

[0032] Partial pouring can also occur if the form, mold, or pump hopper intended to receive the concrete mix is ​​full. As another example, partial pouring can occur if a particular load cannot be accepted, and the unaccepted concrete can be returned to the batch plant or to another location on the same or a different job site where the remaining concrete will be used.

[0033] The meaning of the concept "setting time value or range of values" as used herein and above is: Dependent on the particular application for a given concrete load. This concept can encompass only a single moment (e.g., final cure) or can include periods (e.g., both initial and final cure) calculated from the batch process (or readjustment of the returned concrete). Set time values ​​or ranges of values ​​can include moments or periods for any one or more of the following operations: (a) start of finishing, (b) completion of finishing, (c) removing the framework from the concrete or removing the concrete from the form, (d) allowing foot or vehicular traffic over the concrete, (e) releasing the tensioned cable from the jack (used in prestressed concrete applications), (f) anchoring or grouting the post-tensioned cable (for post-tensioned concrete), or (g) pouring more concrete on top of the previously poured concrete.

[0034] As explained above, for horizontal applications (e.g., pouring concrete highways, slabs, floors, etc.), set time values ​​likely to be of interest include the "initial set time," or in other words, the earliest time (after batching or reconditioning of the concrete) that pushing, leveling, screeding, smoothing, or texturing of the concrete surface with a trowel or other finishing tool can begin (see, e.g., ACI 302.1R-15). If the concrete becomes too hard for finishing, this may be referred to as the "final set time," and this term may also be used to refer to the point after which the form or mold may be removed. See, e.g., ASTM C191-18 a, ASTM C266-18, ASTM C807-18, and ASTM C403-16.

[0035] Other set time values ​​or ranges of values ​​can include initial set times and / or final set times with post-pour concrete properties such as compressive strength, as another example. In some highway slab projects, it is desired to achieve a particular compressive strength target (400 psi) within a given period of time (e.g., 4 hours). Again, the set time values ​​or ranges of values ​​for which it may be desired to monitor and adjust the concrete load will depend on the particular application in which the concrete load is to be used.

[0036] As another example, in a prestressed concrete application where steel wires, cables, or rods are used to prestress the concrete, a set time value or range of values ​​can include the earliest time (from batching) to anchor or grout the cable into the concrete and / or to release the tensioned cable from the jack.

[0037] The term "assignment" or "input" as used herein refers to a set time value or range of values ​​that is input into a processor to monitor and / or adjust a concrete load, which may include, for example, a processor-controlled concrete monitoring system that monitors the rheology (e.g., slump or slump flow) of a concrete mix load contained in a delivery truck drum. As discussed above, this set time value or range of values ​​may be derived from an electronic ticket provided by a concrete batch manufacturer (e.g., many batching plants simply use 15-minute intervals as the batch processing time whereby a delivery truck drives under a powered system that loads cement, sand / rock, and water into a mixer drum and any chemical admixtures). Alternatively, the set time value or range of values ​​may be calculated by an on-board (truck) processor based on the rheology (or slump or slump flow) or other factors by the processor.

[0038] An exemplary method and system of the present invention utilizes an automated slump management (monitoring) system commercialized by GCP Applied Technologies Inc. through its affiliate, Verifi, LLC, both of Cambridge, Massachusetts, USA. It is contemplated by the inventors that such a concrete monitoring system may be implemented using a batch plant or other rheological properties (e.g., slump flow, yield stress, viscosity) during transportation and delivery of the concrete from a batch plant to a work site where the concrete is placed. Various automated process control concrete monitoring systems are described in the patent literature. Such systems may be configured and / or programmed to monitor rheology and various other concrete properties and deliver admixtures to the mix load. For example, U.S. Pat. Nos. 8,020,431, 8,118,473, 8,311,678, 8,491,717, 8,727,604, 8,764,273, and 8,989,905, which are incorporated herein by reference, as well as U.S. Patent Application No. 11 / 834,002 (U.S. Patent Application Publication No. 2009 / 0037026), U.S. Patent Application No. 14 / 052,289, and the like. See the specification (U.S. Patent Application Publication No. 2012 / 0016523), U.S. Patent Application No. 14 / 052,289 (U.S. Patent Application Publication No. 2014 / 0104066), U.S. Patent Application No. 14 / 052,310 (U.S. Patent Application Publication No. 2014 / 0104972), International Application No. PCT / US2015 / 025054 (WO 2015 / 160610), and International Application No. PCT / US2014 / 065709 (WO 2015073825).

[0039] Additionally, it is contemplated that other sensors, such as force sensors (using stress or strain gauges), may be used to monitor the slump of the concrete in the truck mixer drum. See, for example, U.S. Pat. No. 8,848,061 and U.S. Patent Application Publication No. 2015 / 0051737 to Berman (Sensocrete Inc. / GCP See U.S. Patent No. 9,199,391 to Denis Beaupre et al. (IBBRheologie Inc.), or U.S. Patent Application Publication No. 2009 / 0171595 and WO 2007 / 060272 to Benegas.

[0040] Although automated concrete monitoring systems are commonly used to monitor "slump," it should be understood that the present invention includes monitoring of other rheological parameters, such as slump flow, yield stress, viscosity, and other rheological parameters. The specific term "slump" is used for convenience.

[0041] The assigned or entered set time value or range of values ​​may be modified by using an automated concrete monitoring system based on data analyzed by the system processor, as described above. Such data may include data obtained from electronic sensors used at the job site to obtain, for example, moisture, humidity, temperature, or other properties. Data may also be obtained from a concrete monitoring system used on another (e.g., lead) truck pre-delivering concrete at the same pour site, such data may include slump, temperature, moisture content, mix or batch percentages, or other information stored or derived by the on-board monitoring system.

[0042] In various exemplary embodiments, modification of the assigned or entered set time value may be made by the management system processor based on sensor data obtained from sensors used to monitor one or more properties of the concrete after it has been placed (i.e., poured, poured, screeded, leveled, smoothed, etc.) on the job site.

[0043] Sensors placed on or at the concrete surface. The inventors have proposed using one or more mobile or It is envisioned that a portable or portable sensor may be used. For example, one or more sensors may be used on an "unmanned aerial vehicle" (UAV) or drone, or may be hung on a handheld pole, or may be suspended using a cable or pulley assembly that may be moved over a slab, patch, or other segment of poured concrete, as described further in the following paragraphs. As another example, one or more sensors may be used in a nozzle for spraying, pouring, or depositing concrete (e.g., shotcrete, pouring concrete into mines, depositing concrete in a 3D printing process, etc.). The types of sensors that may be used may be selected from optical, infrared, acoustic, radio wave, microwave, electrical resistivity, capacitance, and ultrasonic sensors, as well as other sensor types, all of which are types of sensors known for measuring properties of concrete while it is in its plastic and / or hardened state.

[0044] Sensors on Drones. The phrase "unmanned aerial vehicles" (UAVs), or drones, refers to devices that can be flown by remote control and can carry one or more sensors for monitoring concrete placement at a job site and a wireless transmitter for transmitting data signals to a processor, such as one or more processors in the cloud, one or more other delivery trucks, and / or a processor mounted on a concrete delivery truck that communicates with one or more mobile devices, including on-site smartphones, tablets, or other mobile devices at the job site. For example, in U.S. Pat. No. 8,599,646, Parrot describes using a drone with an ultrasonic telemetry device to measure distance and topography without interference from adjacent drone signals. In U.S. Pat. No. 13 / 998871, Newman describes a data collection system that allows a drone to collect image data, process the data for anomalies, and pair the images to a physical location. U.S. Patent Application Publication No. 14 / 843455 (MetLife) describes the use of drones to collect sensor data, convert the data into insurance-related information, and transmit the data information via wireless communication. There are also improvements that can enable the use of drones in difficult areas. U.S. Patent No. 8,874,283 describes a method that allows drones to be utilized in enclosed spaces and controlled with or without line of sight to the drone, which can be advantageous on construction sites.

[0045] In the construction field, drones have been primarily used to enable digitization and visualization of construction sites (see, e.g., CN 104536456). They have been used to capture aerial images that can be presented to contractors or other site planners (see, e.g., TREMCO SkyBEAM™ asset mapping). U.S. Patent Application Publication No. 2017 / 0016874 discloses that drones can collect data signals from sensors embedded in the concrete of a construction site.

[0046] Sensors embedded in concrete. In an exemplary embodiment of the invention, embeddable sensors may be used. They are placed in the matrix of poured concrete or tied to rebar before the concrete is poured into a form or framework, and transmit data corresponding to the moisture, temperature, hardening, and other properties of the placed concrete via wired or wireless means. For example, embedded sensors have been used in concrete structures for structural monitoring, see, e.g., U.S. Pat. Nos. 4,943,930, 8,913,952), strength development, see, e.g., U.S. Pat. No. 7,551,085, moisture measurement, see, e.g., U.S. Pat. App. Pub. No. 2007 / 0116402, as well as for other applications including corrosion detection, see, e.g., U.S. Pat. App. Pub. No. 2015 / 0048844. Sensors have even been envisioned to be placed inside plastic concrete housed in concrete delivery trucks, see, e.g., U.S. Pat. See U.S. Patent Application Publication No. 2015 / 0212061, and are intended to monitor properties such as slump, temperature, and humidity, among others. These sensors can remain in the concrete as the concrete is poured and can provide, for example, temperature readings that can be used to predict strength development of the hardened concrete slab. Several commercially available sensors can be embedded in the concrete to generate signals indicative of or corresponding to the temperature and / or humidity conditions of the concrete. These include Giatec of Canada (SMARTROCK™ and BLUEROCK2™ sensors), Concrete Sensors Co. of Cambridge, Massachusetts (NOVOCRETE™ sensors), MATOlog of Finland (e.g., CURE™ sensors), Wake Inc. of Granville, Michigan (HARDTRACK™ sensors), Quadrel LLC of Pittsburgh, Pennsylvania (vOrb™ sensors), Flir of Wilsonville, Oregon (INTELLIROCK™ sensors), and AOMS of Canada (LUMICON™ sensors).

[0047] Many of the sensors described above include thermocouples and / or piezoelectric sensors for measuring humidity through electrical resistivity or capacitance measurements, and temperature, which wirelessly transmit data signals to a handheld device, a remote processor, and / or the cloud for real-time monitoring and logging of temperature, humidity, and other maturity data. Signal data from sensors such as these can be correlated with one or more physical properties (e.g., compressive strength at various times after batching) and used by the system processor of the slump monitoring system to adjust the current concrete load, such as by introducing one or more accelerators, retarders, or a mixture of both to the concrete.

[0048] Some of the sensors mentioned in the previous section that can be embedded in concrete can also be used when positioned relative to or placed on the surface of the concrete. For example, one or more sensors can be affixed to a framework or form into which the concrete is poured, or bonded or fastened to rebar, exterior cladding, tunnel walls, foundations, or other structures into which the concrete is poured or sprayed.

[0049] Various exemplary embodiments of the present invention are described below along with some further exemplary aspects of these various embodiments.

[0050] In a first exemplary embodiment, the present invention provides a method for coordinating delivery of concrete, comprising: (A) providing at least two delivery trucks, each having a mixer drum containing a concrete load and a processor controlled system for monitoring the rheology (e.g., slump, slump flow, and yield stress) and at least one set time value or range of values ​​(e.g., initial set time, final set time, compressive strength or a combination thereof, or other values) of the concrete load in the drum, wherein the processor: i. accessing at least one stored set time value or range of values ​​assigned to a load of concrete in a mixer drum for delivery to a job site; ii. calculating at least one current set time value or range of values ​​for the concrete load based on the monitored hydration over time; iii. comparing at least one stored cure time value or range of values ​​with at least one calculated current cure time value or range of values; and (B) Sequential placement of concrete loads poured from at least two delivery trucks. adjusting a current set time value(s) or range(s) of values ​​by introducing a set accelerator, set retarder, or mixture thereof into at least one of the at least two delivery truck concrete loads to perform or modify a finishing, demolding, framing removal, or compressive strength stage; The present invention provides a method comprising:

[0051] In a first aspect of this first exemplary embodiment, the system for monitoring rheology (e.g., slump) can be based on the use of one or more hydraulic sensors (e.g., see U.S. Pat. No. 8,818,561 for sensors on both the charge and discharge pressure ports), force sensors (e.g., strain gauges or stress gauges), acoustic sensors, or combinations thereof. Various known rheology monitoring systems have been described above. A particularly preferred monitoring system is based on a hydraulic sensor in combination with a drum rotation speed monitor (e.g., a gyroscope, an accelerometer on the drum, or both). Either stored or current set time value or range of values ​​can be generated, for example, by monitoring the temperature change of the concrete load over time, preferably at a given concrete slump, using an automated slump monitoring system. Monitoring the concrete load over time can be done in several ways. For example, the temperature of the concrete load can be measured over time and taken into account along with the batch volume (including the load size at the batch plant and any additional water or admixtures added at any time, plus the age of the concrete). The concrete load after pouring at the job site will have set time values ​​or ranges of values ​​that preferably do not coincide, although there may be some overlap. In other exemplary embodiments, the first job site may not be the final "pour site," in which case trucks are rerouted from the first job site to travel to another job site to deliver the full or partial load. Adjusting the current set time value or range of values ​​for the concrete load may be accomplished, for example, by managing dosages of accelerators, retarders, or mixtures thereof.

[0052] In a second aspect of the first exemplary embodiment, the phrase appearing in section A(ii) above including "calculating at least one current set time value or range of values ​​for the concrete load based on the monitored hydration over time" may include one of many known methods for tracking the hydration of concrete over time, including tracking temperature change or rate of temperature change, as well as other known means of tracking water content, slump change, or hydration state. Such tracking preferably includes information regarding the amount of cementitious material initially batched with the concrete ingredients in the mixer drum, which may be obtained from a ticket issued by the batching plant.

[0053] In a third aspect of the first exemplary embodiment, at least two of the at least two concrete delivery trucks carry concrete loads originating from different batch plants.

[0054] In a second exemplary embodiment, which may be based on the first exemplary embodiment above, the present invention provides a method, wherein in step (A), at least three delivery trucks (more preferably at least six trucks) are provided, each having a mixer drum containing a concrete load and a processor control system for monitoring the rheology and monitoring the set time value or range of values ​​of the concrete load in the drum, the processor being programmed to perform functions (i), (ii) and (iii) as described above, and each of the at least three delivery trucks (more preferably at least six trucks) adjusts a stored set time value or range of values ​​or a current set time value or range of values ​​of the concrete load.

[0055] In a third exemplary embodiment, which may be based on the first or second exemplary embodiment above, the present invention provides a method, in which both a stored cure time value or range of values ​​and a current cure time value or range of values ​​are adjusted.

[0056] In a fourth exemplary embodiment, which may be based on any of the above first to third exemplary embodiments, the present invention provides a method, in which a stored set time value or range of values ​​is calculated based on factors including an estimated age of the concrete at the time of pouring. The estimated age may be calculated based on, for example, traffic, work site conditions, or other factors.

[0057] In a fifth exemplary embodiment, which may be based on any of the first through fourth exemplary embodiments above, the present invention provides a method, wherein the set time value or range of values ​​is selected from time values ​​for (a) starting finishing, (b) completing finishing, (c) removing the framework or form from the concrete, (d) allowing foot or vehicular traffic over the concrete, (e) releasing the tensioned cable from the jack (used in prestressed concrete applications), (f) anchoring or grouting the post-tensioned cable (with respect to the post-tensioned concrete), or (g) pouring more concrete on top of the previously poured concrete.

[0058] In a sixth exemplary embodiment, which may be based on any of the first through fifth exemplary embodiments above, the present invention provides a method for determining whether a stored set time value or a range of values ​​accessed, or accessed and adjusted, by at least one of the delivery truck processor control systems is based on: (a) ticket information provided by a batch plant that procured the concrete in the truck mixer drum (e.g., the ticket information may include a mix design, material batch weight, concrete load volume, water content or water / cement ratio, or a combination thereof); (b) a supervisor at a job site where the concrete is poured from the truck mixer drum (e.g., the supervisor may provide information about ambient temperature, relative humidity, wind speed, UV index, traffic congestion, worker conditions, etc.); (c) a processor receiving data signals from a humidity, moisture, and / or temperature sensor (or combination of such sensors) embedded within, positioned relative to a surface of, or embedded in concrete poured or placed at the work site or another work site; or (d) a processor monitoring another concrete delivery truck (e.g., a main delivery truck or other delivery truck pouring concrete at a work site having a previous set time value or range of values) having a processor controlled system for monitoring the rheology and set time value or range of values ​​of the concrete load.

[0059] In a first aspect of the sixth exemplary embodiment, humidity, moisture, and / or temperature sensors may be embedded within and / or placed on the surface of the poured concrete.

[0060] In a second aspect of the sixth exemplary embodiment, one or more sensors may be suspended above the poured concrete at the job site using an aerial drone, cable, pole, or other suspension means. Preferred sensors for this application may be selected from optical, infrared, acoustic, radio wave, microwave, electrical resistivity, electrical capacitance, and ultrasonic sensors, or combinations thereof. These sensors may provide data signals indicative of the hydration state or rate of the concrete, and such data signals may be transmitted, preferably wirelessly, so that a system processor on board the delivery truck can monitor the current hydration state of the concrete load and can record and store the information, so that subsequent measurements can be made. can be used as historical (stored) information and correlated with a target cure time value or range of values.

[0061] In a third aspect of the sixth exemplary embodiment, the sensor (e.g., conductive, ultrasonic) may be used in one or more nozzles or hoses used in spray application of shotcrete, in nozzles for depositing concrete in a 3D printing process, or in hoses for pouring or depositing concrete at a work site, such as in nozzles for extruding concrete sections, such as for creating tunnels or precast concrete shapes.

[0062] In a seventh exemplary embodiment, which may be based on any of the first to sixth exemplary embodiments above, the present invention provides a method further comprising the steps of adjusting at least one stored curing time value or range of values, and providing a report or indication of the adjustment made to the at least one stored curing time value or range of values. In a first aspect of this example, the monitoring system of the delivery truck can use at least one stored curing time value or range of values, e.g., initial curing time, final curing time, time to remove the framing from the concrete, and adjust the stored value or range of values ​​based on new data information, such as obtained as described in the sixth exemplary embodiment above. Thus, a supervisor at a work site where the concrete is poured (or sprayed or placed) can send an instruction to the processor to add 5 or 10 minutes to the curing time for delays at the work site. As another example, a remote processor, or even a processor used to monitor a concrete load in a delivery truck, can receive a data signal or other information derived from a sensor embedded in or positioned on or against previously poured concrete and adjust a stored set time value such that the truck system processor can adjust the current set time value of the concrete load in the truck using the revised value. In a further example, the system allows for recording or confirmation of adjustments made to stored set time values ​​or ranges of values.

[0063] In a second aspect of this exemplary embodiment, adjustments to the stored set time values ​​may be transmitted to or retrieved by concrete monitoring systems on other concrete delivery trucks and used to adjust pouring and finishing events at the pouring site.

[0064] In an eighth exemplary embodiment, which may be based on any of the first through seventh exemplary embodiments above, the present invention provides a method for comparing a current set time value or range of values ​​with a stored set time value or range of values ​​with respect to at least one factor selected from temperature of concrete, rate of temperature change of concrete, batch amount or mix design of concrete, adjustment of water or admixtures (e.g., cement dispersants, chemical plasticizing or superplasticizing admixtures) added to the concrete load, rheology (e.g., slump, slump flow, yield stress), or other property of concrete.

[0065] In a ninth exemplary embodiment, which may be based on any of the first to eighth exemplary embodiments above, the present invention provides a method for producing a concrete mixer comprising the steps of: (a) providing a concrete mixer having a set time of 1000 to 2000 sq. m; (b) providing a concrete mixer having a set time of 1000 to 2000 sq. m; and (c) providing a concrete mixer having a set time of 1000 to 2000 sq. m; and (d) providing a concrete mixer having a set time of 1000 to 2000 sq. m. and (e) providing a concrete mixer having a set time of 1000 to 2000 sq. m. and (f) providing a concrete mixer having a set time of 1000 to 2000 sq. m. and (g) providing a concrete mixer having a set time of 1000 to 2000 sq. m. and (g) providing a concrete mixer having a set time of 1000 to 2000 sq. m. and (h) providing a concrete mixer having a set time of 1000 to 2000 sq. m. and (h) providing a concrete mixer having a set time of 1000 to 2000 sq. m. and (g ...

[0066] A tenth exemplary embodiment may be based on any of the above first to ninth exemplary embodiments. In one embodiment, the invention provides a method for pouring a concrete load into a predetermined location from a first delivery truck, and while the first concrete load is in a plastic state, a second concrete load from a second delivery truck is poured on top of the first concrete load, the first load and the second load having overlapping set time values ​​or ranges of values.

[0067] For example, in U.S. Patent No. 7,968,178, Scurto et al. disclosed that a first slab of concrete can be poured onto a first concrete slab while still in a somewhat plastic state to create an integrated area between successively poured slabs. In this manner, the invention can allow for a slight overlap in set time values ​​or ranges of set time values, such as between successive or adjacent concrete load deliveries at a job site, to facilitate bonding between concrete poured, sprayed, printed, deposited, or otherwise placed onto a previous concrete that is still in a plastic state. In the construction industry, one may hear contractors speak of pouring a "first lift" (e.g., a first concrete mass or configuration) and then pouring a "second lift" on top of the first lift. This is often associated with poured self-consolidating or self-compacting concrete. Concrete can be poured quickly due to its fluidity, but fluid concrete can impart significant forces to the framework, increasing the risk of a "blowout" in which the framework fails catastrophically. Based on the adjusted curing time, the flowable concrete can be left to harden, at which point the next "dose" can be safely poured.

[0068] In an eleventh exemplary embodiment, which may be based on any of the first to tenth exemplary embodiments above, the present invention provides a method, in which a stored set time value or range of values ​​of concrete previously delivered and placed at a work site is obtained or derived from a data signal generated by at least one sensor in a nozzle, hose, or other conduit of the concrete during deposition or spraying of the concrete through the nozzle, hose, or conduit at the work site. For example, the sensor can be an electrical conductivity sensor (or two electrodes spaced apart in the nozzle and / or hose such that an electrical current can be sent through the electrodes and the conductivity of the concrete can be measured), or the sensor can be a sensor of the aforementioned types (e.g., infrared (IR), ultrasonic).

[0069] In a twelfth exemplary embodiment, which may be based on any of the first through eleventh exemplary embodiments above, the present invention provides a method, in which a portion of at least one concrete load in a delivery truck is poured at a first job site, and within 15 minutes, more preferably within 10 minutes, of pouring, a dose of set retarder is introduced into the remaining portion of the concrete load in the delivery truck, and the remaining portion is transported by the delivery truck to a second job site and poured into a predetermined location at the second job site. In a further aspect of this example, at least one subsequent dose of set retarder is administered to the remaining portion of the concrete load during its travel from the first job site to the second job site.

[0070] In a thirteenth exemplary embodiment, which may be based on any of the above first to twelfth exemplary embodiments, the present invention provides a method, wherein at least five (more preferably at least ten) delivery trucks are provided according to step (A) having a concrete load, for which a set time value or range of values ​​is adjusted according to step (B), said adjustment being performed using calculation of the set time value or range of values ​​based on signal data obtained or derived from at least one sensor for monitoring the hydration over time of concrete placed at a work site.

[0071] In a first aspect of the thirteen exemplary embodiments, hydration signal data over time for multiple concrete placement locations at a job site is collected using optical, infrared, acoustic, radio, microwave, electrical resistance, or other methods. The signal is generated by at least one sensor selected from resistivity, capacitance, and ultrasonic sensors, the at least one sensor being preferably moved over the concrete placement site using an aerial drone. A processor, such as one used to monitor the rheology of a truck concrete load, can be programmed to compare the obtained data signals with previously stored data signals to obtain a set time value or range of values ​​that correlates with hydration data over time obtained from at least one sensor, and in an exemplary embodiment, a processor, such as a personal computer, laptop computer, or portable smartphone or smartwatch, can be used to generate a pictorial or map of multiple concrete placement locations along with set time values ​​or ranges of values, or suggested sequence priorities based on set time values ​​or ranges of values, thereby providing placement instructions suitable for sequential processing with respect to (a) starting finishing, (b) completing finishing, (c) removing the framework or form from the concrete, (d) allowing foot or vehicular traffic over the concrete, (e) releasing the tensioned cable from the jack (e.g., as used in prestressed concrete applications), (f) anchoring or grouting the cable after tensioning (e.g., for post-tensioned concrete), or (g) pouring more concrete on top of the previously poured concrete.

[0072] In a second aspect, the hydration state of the various positioned concrete sections can be displayed on a visual monitor in terms of darkened sections that correspond to a hydration state in darkness, or in terms of other visual aids.

[0073] In a fourteenth exemplary embodiment, which can be based on any of the above first to thirteenth exemplary embodiments, the present invention also provides a method for monitoring a cure time condition of a placed concrete load, the method comprising: moving at least one aerial drone having at least one sensor (e.g., a sensor selected from optical, infrared, acoustic, radio wave, microwave, electrical resistivity, electrical capacitance, and ultrasonic sensors) for monitoring the hydration of the placed concrete over time at a job site over a plurality of concrete placement locations to obtain a data signal indicative of hydration; comparing the obtained data signal to previously stored data signals to obtain a set time value or range of values ​​that correlates with the hydration data obtained from the at least one sensor over time; generating a pictorial or map of multiple concrete placement locations along with set time values ​​or ranges of values, or suggested sequence priorities based on set time values ​​or ranges of values, thereby providing placement instructions suitable for sequential processing for (a) starting finishing, (b) completing finishing, (c) removing the framework or form from the concrete, (d) allowing foot or vehicular traffic over the concrete, (e) releasing the tensioned cable from the jack (e.g., for prestressed concrete applications), (f) anchoring or grouting the cable after tensioning (e.g., for post-tensioned concrete), or (g) pouring more concrete on top of the previously poured concrete; Includes.

[0074] In a first aspect of this fourteenth exemplary embodiment, the pictorial diagram or map may be generated on a handheld device or, as another example, on goggles worn by a site supervisor. The pictorial diagram may be, for example, a photo or image of a concrete delivery truck seen on a pour site map, allowing digital values ​​and / or colors to be overlaid on the truck image or the concrete segment image. Thus, the site supervisor can be advised to enter the line for pouring or to stop pouring according to visual information on the pouring status (i.e., curing time value). In one embodiment, the delivery truck can be directed to deliver concrete to a desired location and / or finishing crews can be directed to those segments of poured concrete that have the required set points or characteristics.

[0075] FIG. 3 is a block diagram illustrating an exemplary process according to certain embodiments of the present invention. First, concrete is delivered to a placement location (block 22), and then the concrete is poured, spread, and compacted (block 24). For each concrete delivery truck load (or group of concrete delivery truck loads) of concrete thus placed, the UAV (or fleet of UAVs) can determine one or more perimeters of the placed concrete using telemetry based on optical and thermal signals (block 26). For example, since the framework and the concrete typically have different temperatures, color differences (determined from comparison of sequential images) or thermal signatures from the concrete can delineate the poured concrete from the framework edges or the pre-placed concrete. Alternatively, image analysis comparing pre- and post-pouring can also help determine the perimeter of the placed concrete. Using this information, a processor-accessible database can be uploaded, along with, for example, the identity of the concrete delivery truck that delivered the concrete (e.g., concrete delivery truck number), the batch ticket (containing the concrete ingredients or mix design, e.g., water content), the time the concrete was poured, and the location of the concrete. This information helps determine if all compartments of the form are properly filled and, if not, can alert the contractor to vibrate and add more concrete.

[0076] Also, as shown in FIG. 3, the concrete article can be monitored for different characteristics (blocks 30, 32, 35, 36 and 38). For example, a UAV can scan a poured concrete article for differences in density that may indicate a consolidation problem that should be addressed before the concrete hardens. Available technologies that may be used by a UAV to do this include nuclear density meters, ground penetrating radar, or capacitance energy dissipation (see, e.g., U.S. Pat. No. 5,952,561). The inventors also envision that air-coupled surface wave measurements can be used in the present invention (see, e.g., U.S. Patent Application Publication No. 2013 / 0289896). If a density difference is found (block 40), the affected area can be relayed to the contractor, for example, by a mobile application, so that the contractor can visually see where the consolidation needs to be addressed by further compaction or vibration. This can be accomplished, for example, by inserting a vibrating rod at the specified location, and additional concrete may even need to be added. Additionally, augmented reality techniques may be utilized to more easily view problem areas (see, for example, US Pat. Nos. 8,922,590 and 8,943,569, both of which are incorporated herein by reference).

[0077] After placement and consolidation, the UAV (drone) can periodically scan the topography of the concrete article using imaging devices such as optical telemetry or terrestrial laser scanning, for example, to determine areas of high and low spots requiring refinishing. During the screeding and initial floating processes (which include press-on leveling, straightening, and finishing troweling), the UAV can periodically scan the concrete article to determine properties such as surface moisture, which may be determined by optical telemetry (e.g., optical reflectance or comparison of past and current images), water-sensitive near-infrared sensing (see, e.g., U.S. Pat. No. 7,265,846, incorporated herein by reference), radar (see, e.g., U.S. Pat. No. 9,207,323, incorporated herein by reference), among other methods. Periodic scanning can include continuous scanning, or can include continuous scanning, such as fly-bys every 5 minutes or every 10 minutes, based on the hardening rate or changes in hardening rate of the concrete. It is considered that it is necessary to perform it frequently. The route of the flyby may also be changed, for example, based on the area of ​​the concrete article being monitored, or simply the unobstructed flight route. Once measurements are collected over time and space over the concrete article, a predictive mathematical model can be built so that the surface moisture can be predicted. Such a model can be used to transmit useful information to the contractor at the building site. Mobile applications or augmented reality methods can be used on a laptop or smartphone device to show, for example, a section of poured concrete that has surface moisture that will soon exceed a predetermined threshold, so that the contractor can determine when and where screeding and initial floating must be completed (see block 42 in FIG. 3). Screeding and / or initial floating outside the applicable workability window leads to dusting or scaling of the concrete surface and therefore repair costs that should be avoided.

[0078] FIG. 4 shows a bird's-eye view of a poured concrete slab. This initiates a discussion of how a useful mathematical model can be generated to generate a visual display of the setting time behavior of a poured slab. Moisture measurements are made at two pour sections, A and B (shown side-by-side for convenience). FIG. 5 shows the moisture of each slab section, A and B (66 and 75%) at a specific time (t=20 minutes). The measurement locations do not need to be aligned on a grid or taken consistently at the same location. For the purposes of this discussion, the location of the measurements over time is kept constant. Measurements are taken at each of the two locations (A and B shown in FIG. 4) over time. As more data is collected, the model can be refined in real-time. In other words, with each new data point collected, the model is rebuilt or refined to take the new data into account. The predictive model aims to detect one or more features of the data curve that relate to the monitored property (e.g., temperature, strength, setting time or moisture) over time. The feature can be a local or global extremum (e.g., a peak or valley), or an inflection point, or simply above or below a predefined threshold. In this case, we assume that the inflection point in the curve representing moisture over time represents the optimal time to finish the concrete. Again, finishing the concrete requires a minimum slab stiffness and maximum moisture at the surface. Furthermore, as the concrete hardens and more water leaves the surface, it becomes more difficult to finish. Thus, an optimal time exists.

[0079] In FIG. 5, the complete moisture evolution since the optimal time is plotted for each section. The markers "O" and "X" represent collected data, while the line represents a logistic function fit using standard least squares methods. The shaded areas indicate the appropriate finishing window for sections A and B. This may be determined by a comparison between historical data, for example, a penetration test (see, for example, ASTM C403-16) that directly measures the finishing window and compares it to sensor data signals obtained over the same period of time. As can be seen, an inflection point exists within the window. Thus, if the inflection point can be determined in real time, the contractor may be alerted to begin the finishing process.

[0080] In some cases, it may be more useful to alert the contractor at the beginning of the finishability time window rather than the middle of the window. In this case, the second derivative may be calculated using standard computational techniques for an assumed form of a function that fits the data (e.g., logistic, quadratic, linear, etc.). The second derivative with respect to time may be calculated numerically using finite differences. Using the latter process, smoothing of the original data may be necessary, but an assumed functional form (e.g., logistic) need not be assumed, which may be an advantage when the form of the function is difficult to determine in advance.

[0081] FIG. 6 is a graph diagram of another exemplary embodiment showing when finishing can begin or be completed. To suggest, the second derivative can be used to generate higher resolution data.

[0082] Additionally, further analysis can be performed to predict time values ​​at which finishing can begin and end. Taking the third derivative with respect to time can be useful for monitoring how close the third derivative, which indicates a maximum or minimum value of the second derivative, is to zero. Based on how quickly the third derivative is converging to zero, the times at which the maximum and minimum values ​​will occur (and thus the start and end of the finishing window) can be predicted and reported to the contractor or other job site personnel.

[0083] After the initial floating operation is performed, the concrete must be stiffened slightly before edging or joining is performed, but such stiffening is described as "maintaining a foot pressure with only about 1 / 4 inch (6 mm) of indentation." See, for example, ACI 302.1R-15. Alternatively, drone-mounted sensors may be used for periodic monitoring of properties such as concrete stiffness via pressure means (e.g., drone-mounted force probes or penetrometers), via ultrasonic transducer / receiver / transmitter units to measure shear sound waves or Rayleigh waves, or, as another example, via electrical resistivity or temperature sensors. By measuring continuously over time and space (areas of a concrete article such as a slab), a predictive mathematical model may be constructed to predict stiffening in a similar manner as described above. For example, monitoring temperature for initial setting may indicate the time to finish the concrete article. By taking the second derivative of temperature with respect to time (using an assumed function or via finite differences), a local maximum in the second derivative may indicate initial setting. Similar approaches may be taken with outputs from other sensors, as described above. This information may be presented using such mathematical models to provide a visual indication as to which portions of poured concrete sections indicate sufficient (e.g., above a predetermined threshold). Using this information, the contractor may instruct the finisher to begin power floating and troweling on a particular section of concrete. The placement sequence of the concrete may not accommodate sections that require earlier attention, for example, because concrete placed in areas exposed to a greater degree of sun or wind may have accelerated the set time behavior, or inconsistencies in truck loads of concrete, for example (see, e.g., block 44 of FIG. 3), may also change the set time behavior.

[0084] Once power floating is complete, and during the troweling operation, the UAV can periodically scan the concrete article to determine the surface color and texture by optical telemetry or terrestrial laser scanning (block 46 in FIG. 3). Continuous measurements (of areas of the article, e.g., areas of the slab) over time and space allow comparison between locations (block 50) so that locations that are out of specification (e.g., by color analysis) or not finished (e.g., by texture analysis) can be relayed to the contractor (again, e.g., via a mobile application or augmented reality) to indicate areas that no longer need to be troweled and areas that still require finishing. This can prevent detrimental surface color and texture variations.

[0085] While Figures 4-6 show the use of a time and space model of a simple grid of two plots where measurements were collected in the centre of the plot at regular intervals, Figures 7a-d show how predictive models can be developed in a more complex, but more generalised way, by using data collected using one or more sensors mounted on an unmanned aerial vehicle (UAV), commonly referred to as a drone.

[0086] In Figure 7a, 50 virtual measurements are collected using sensors on a drone. , each measurement location is shown as a circle with a number next to it. The measurements do not have to be made on a regular grid. In each of 7a-7d, 50 measurements were used to create a Voronoi diagram. Each Voronoi "cell" is a region associated with each measurement. This is a standard way of dividing an area into zones based on groups of points within the area. Essentially, for each measurement, a region or cell is defined as all the areas that are closer to that measurement than any other measurement. Figure 7a uses shades of grey for each zone that correspond to normalized values. For example, this could represent moisture, temperature, or stiffness, or even acoustic measurements of the article. Figure 7a further shows normalized values ​​across the article 10 minutes after a reference time (e.g., when the concrete was placed or when the concrete was batched).

[0087] 7b-7d show subsequent virtual set time value (hydration state) measurements using one or more sensors on a drone (UAV) placed over various sections of poured concrete at 30, 60, and 80 minutes, respectively, after the reference time. The measurements do not necessarily have to be at the same location as in the previous period. If different locations are measured over time, preferably multiple measurements should be taken to obtain a representative sampling. It is envisioned that similarly behaving sections of poured concrete can be grouped together (e.g., if the temperature difference between the two is below a predefined threshold). As time progresses, as shown in the exemplary embodiment shown in Figs. 7a-7d, the shaded areas darken, but not all at the same rate. In particular, the bottom right corner does not darken as quickly as the rest of the article. This may simply be the result of this section being poured at a later time than the rest of the article, or it may be for more complex reasons, such as the concrete mix not being the same (e.g., different water content in a particular load). In any case, the data collected for each period for each area (in this case the lower right corner area and the complementary area) can be used to develop a relationship or model over time.

[0088] Figure 8 shows a hypothetical example of the model proposed above. Each marker represents the average sensor measurement or data signal value for a particular area in a given period. At 60 minutes, the data is used to fit a model to predict future behavior represented by the dotted portion of each curve. The horizontal dash-dotted line can represent a threshold that triggers a finishing event such as "start power floating". This trigger point can be determined by comparing the measurements with empirical data obtained from past deliveries. More preferably, a particular characteristic (or combination of characteristics) can be correlated with the trigger point.

[0089] Figure 8 also shows how a logistic function can be used in the model. The trigger point can be correlated to an inflection point in the logistic data curve, e.g., the point where the curve changes from concave to convex (or vice versa). Using this example, power floating of the concrete section shown in the lower right area of ​​Figure 7c can begin in about 20 minutes, while power floating of other sections can begin in about 3 minutes. This predictive tool can prevent serious surface damage from (for example) power floating activity that is too early or too late.

[0090] Many different sensors can provide measurements over both time and space to obtain information that can indicate when to start and complete different stages of the finishing process. Relationships can be developed between physical phenomena such as changes in surface moisture or stiffness of the concrete article. Some of these relationships exist in the literature, for example between penetration tests and slab stiffness. Other relationships require more detailed analysis and additional parameters. For example, when using optical sensors, machine vision (see, for example, Machine Vision, R. Jain, R. Kasturi, B. Schunck) provides useful mathematical tools to extract features on subsequent images that can be related to changes in surface moisture, for example. The determination of color, shading and texture characteristics can be particularly useful. For example, mean intensity, entropy, energy, contrast, uniformity and correlation calculations can be used to analyze subsequent images over time (see, for example, Machine Vision, R. Jain, R. Kasturi, B. Schunck, pp. 234-248). Different characteristics are more or less sensitive to different situations (e.g. indoor slabs vs. outdoor slabs).

[0091] Beyond improving finishing operations, drones have other uses. For example, the same methods of collecting data from concrete articles in both temporal and spatial ways can be used to generate mathematical models of temperature, hydration (e.g., initial and final set), concrete strength (e.g., via maturation methods such as ASTM C1074-17), and moisture changes over time. As each point or group of points is recorded, the sensor measurements can be fed into a processor to regenerate a predictive model or update it to include the new data points. Thus, the predictive model adapts to new data and is not simply a static model. This prediction can further enable contractors to make logistical decisions at the job site.

[0092] Additionally, the set time predictions (initial and final set, as well as the time to begin surface finishing or the time when surface finishing can be completed) may be recorded along with all other data related to concrete, including which concrete delivery truck loads contributed to the section of concrete article, the batch weight of each concrete delivery truck load, the slump of each concrete delivery truck load, other rheological properties of the concrete delivery truck load, the air content of the concrete delivery truck load, the total water and admixture doses including those dosed during the transport of each concrete delivery truck load, etc. By collecting and recording these data as they are generated in a database, additional predictive models can be generated that relate the relevant data for a given load (i.e., pre-pour data) to the post-pour data including set time. Thus, set time can be predicted for a given concrete delivery truck load destined for a particular job site. This is illustrated throughout Example 4 below.

[0093] Alternatively, a set time estimate can be obtained by assuming that a particular load of the same job will have a similar set time as previous loads if the pre-pour conditions are similar (e.g., total water content within 5 pounds per cubic yard of concrete, or slump within 1 inch, etc.). The predicted set time can be used and compared to the target set time to establish the set time difference. Based on this difference, along with any extra time needed, the appropriate dosage of set retarder can be calculated and administered to adjust the concrete set time, which in turn can adjust placement within the concrete route or reroute, as described in the detailed description of the hypothetical example below.

[0094] FIG. 9 shows an example of two batch plants, each of which normally supplies two work sites. The invention allows partial or complete loads that are unused or rejected at one site to be sent directly or indirectly to the other site. Plant 1 (P1 at 102) and Work Site A (J at 104) are A) has a transport time of 45 minutes (1-way). B The transit time for route 114 to plant 2 (P2 at 116) is 25 minutes. B The route between P2(106) and J has a transit time of 10 minutes. A The transit time between (104) and (116) is 6 minutes. A and J. B The transit time between the two locations is 12 minutes.

[0095] Referring to FIG. 9, for purposes of illustration, assume that Plant 1 (102) is dedicated to delivering to Worksite A and Plant 2 (106) is dedicated to delivering to Worksite B (108). Thus, the present invention allows for a scenario in which concrete from Plant 1 to Worksite A (104) is rejected at Worksite A, but can be delivered to Worksite B (108). To receive a ticket authorizing this re-route or to make adjustments to the mix (e.g., add cement), the concrete delivery truck must typically travel route 110 in both directions (i.e., back to Plant 1 at 102) and then route 112 to Worksite B at 108. The total time required for this travel is 45×2+25=115 minutes (not including the time required to receive the ticket and adjust the concrete). Typically, Worksite B (108) receives concrete from Plant B (106) via route 114, which typically requires only 10 minutes. Thus, the rejected delivery from Plant 1 is 105 minutes out of date (115 minus 10=105) compared to a typical delivery from Plant 2 to Worksite B traveling along route 114. It is therefore not surprising that the finishing time of concrete from Plant 1 is different compared to concrete from Plant 2. This leads to serious problems as concrete from Plant A may harden 105 minutes faster compared to concrete normally delivered from Plant B (106) to Job Site B (108).

[0096] Referring to FIG. 9, for purposes of illustrating another example, if one considers concrete from Plant 2 (106) to Worksite B (108) via route 114 being rejected for use at Worksite B, then intended for reuse at Worksite A, the delivery truck would normally have to travel route 114 twice (because it would normally have to return to Plant 2 to obtain a ticket authorizing delivery to Worksite A) and then travel route 116 to Worksite A. The total time (again not including the time to receive a new ticket and adjust the mix design) would be 10×2+6=26 minutes, which is 19 minutes less than a typical concrete delivery from Plant 1 to Worksite A. The concrete from Plant 2 would arrive at Worksite A sooner and harden 19 minutes slower compared to the concrete from Plant 1.

[0097] In a further exemplary illustration based on FIG. 9, assume that Plant 1 (102) is dedicated to deliveries to Worksite A (104), while Plant 2 (106) is dedicated to deliveries to Worksite B (108). Also assume that a concrete load delivered from Plant 1 to Worksite A is rejected, but can be delivered to Worksite B. In an exemplary embodiment of the invention, an electronic ticket can be issued as soon as the concrete delivery truck is confirmed to deliver to Worksite B. This eliminates the need for the concrete delivery truck located at Worksite A to return to Plant 1. The delivery time from Plant 2 to Worksite B can be sent to a processor for the concrete management system to control the monitoring of the concrete load on the concrete delivery truck. This can be based, for example, on the time of the last delivery, an average of several past deliveries, or an early prediction of the next delivery. The processor also receives an estimate of the current concrete delivery truck to reach Worksite B from Worksite A, including the time the concrete has already traveled from Plant 1 to Worksite A. In this case, the delivery time from plant 2 to worksite B via route 114 is 10 minutes, and the delivery time from plant 1 to worksite A and from worksite A to worksite B is 57 minutes in total. Thus, the concrete originating from plant 1 is 47 minutes older than the concrete originating from plant 2. In this case, the processor calculates the amount of retarder required to retard the concrete by 47 minutes, and the retarder is dosed accordingly to the concrete delivery truck. The dosing may be performed manually or automatically.

[0098] FIG. 9 also makes it possible to consider a further scenario, made possible by the present invention, in which a concrete delivery from Plant 2 (106) to Worksite B (108) is rejected for use at Worksite B, but can be used at Worksite A. In this case, Plan When delivery from Plant 2 to Worksite B occurs and concrete is needed for Worksite A, an electronic ticket can be issued (e.g., to a processor controlled management system on board the delivery truck) so that the truck does not need to return to Plant 2 and then travel from Plant 2 to Worksite A. The delivery time from Plant 1 to Worksite A can be transmitted to or stored in the truck, as well as an estimate for the current concrete delivery truck to reach Worksite A including the time already traveled. Thus, in this example, the delivery time from Plant 1 to Worksite A is 45 minutes, and the delivery time from Plant 2 to Worksite B and Worksite B to Worksite A totals 22 minutes. Thus, the concrete originating from Plant 2 is being batched 22 minutes after the batch time of the concrete normally delivered from Plant 1 to Plant 2. In this case, the processor calculates the amount of accelerator needed to advance the concrete by 22 minutes, and the accelerator is dosed into the concrete delivery truck. The accelerator can be dosed either manually or automatically. Alternatively, the concrete delivery truck driver or worksite coordinator is instructed to wait approximately 22 minutes before pouring the concrete.

[0099] In yet a further example of the advantages and features of the present invention, using FIG. 9 as an example, assume that Plant 1 (102) is dedicated to deliveries to Worksite A (104) and Plant 2 (106) is dedicated to deliveries to Worksite B (108). Also assume that a concrete delivery truck moving from Plant 1 to Worksite A is rejected, but can deliver to Worksite B. In addition, the mix design of the current concrete delivery truck needs to be adjusted to match the mix requirements of the concrete articles at Worksite B. As soon as the concrete delivery truck is confirmed to deliver to Worksite B, an electronic ticket is issued. A processor accessible by the concrete delivery truck receives the delivery time from Plant 2 to Worksite B. This can be based, for example, on the time of the last delivery, an average of the past few deliveries, or a forward prediction of the next delivery. The processor also receives a time estimate, including the time already traveled, for the current concrete delivery truck to arrive at Worksite B, and a time estimate required to adjust the mix design in the concrete delivery truck, including the batching at the given plant. At this point, the processor is programmed to consider two alternatives. The first alternative is for the concrete delivery truck to return to Plant 1, condition the mix, and travel to Work Site B. The second alternative is for the concrete delivery truck to travel to Plant 2, condition the mix, and travel to Work Site B.

[0100] In the first alternative, the total time between Plant 1, Worksite A, and back to Plant 1 and Worksite B (via routes 110, 110 and 112) is 45×2+25=115 minutes (excluding time to adjust the mix design). The time difference between this drive time and the time estimate between Plant 2 and Worksite B is 115-10=105 minutes. Thus, retarder is required. In this alternative, at Worksite A, the concrete is dosed with retarder (automatically or manually) to adjust for the 105 minutes. Once the concrete delivery truck is adjusted at Plant 1, additional material can be dosed with retarder to cover the drive time between Plant 1 and Worksite B. The entire dose can be added at Worksite A.

[0101] In the second alternative, ignoring the time to adjust the mix design, the total time between Plant 1, Work Site A, Plant 2, and Work Site B (numbers 110, 116, and 114) is 45+6+10=61 minutes. The time difference between this travel time and the time estimate between Plant 2 and Work Site B is 61-10=51 minutes. Again, retarder is required. However, in this case, if retarder is injected to account for the time between Plant 1, Work Site A, and Plant 2 (including any time needed to adjust the mix design), the remaining legs of the trip are the same as a delivery made directly between Plant 2 and Work Site B, so no further delay is required. No adjustment is required.

[0102] In the above examples, to simplify the calculation of the time difference, the time to adjust the mix design was not included. If the mix design should be adjusted, one skilled in the art based on the disclosure herein would know how to adjust the time to compensate for the exact age of the concrete. For both of these cases, a "dribble dose" can be used. Thus, instead of measuring an exact dose of retarder, enough retarder is added to be effective for a period of time, e.g., 15 minutes. After this period has expired, if more retarder is needed, another dose is added, and so on. This is discussed and illustrated in Example 5.

[0103] The embodiments disclosed herein are described herein using a limited number of exemplary embodiments, but these specific embodiments are not intended to limit the scope of the invention described and claimed elsewhere. Modifications and variations from the described embodiments exist. More specifically, the following examples are given as specific illustrations of the claimed embodiments. It should be understood that the embodiments are not limited to the specific details described in the examples. All parts and percentages in the examples and the rest of the specification are by percentage of dry weight unless otherwise stated.

[0104] Example 1 FIG. 10 graphically illustrates experimental optical measurements over time for a concrete slab. 3 ) Cement, 1700lbs / yd 3 Stone, 1425lbs / yd 3 of sand, 300lbs / yd 3of water and 7.5 ounces / 100 pounds (oz / cwt) of cementitious material at WRDA® 64, a low range water reducer (LRWR). The concrete was mixed according to the following protocol: Stone, sand, and 80% of the water were mixed on high speed for 2 minutes. The remaining water was added to the cement and mixed on high speed for 2 minutes. The LRWR was added and mixed on high speed for 2 minutes. The mixer was turned off and the concrete was allowed to sit for 3 minutes. Mixing resumed on high speed for 3 minutes. After mixing, a portion of the concrete was tested for slump and air, and the remaining concrete was poured into a 2 ft x 3 ft x 6 inch slab, screeded, and hand leveled. After this, images were acquired every 5 minutes from a fixed camera (envisioned to be replaced by a UAV according to embodiments disclosed herein). From each image, the mean, median and standard deviation of the gray scale were determined using typical image analysis tools (see, e.g., Solomon, C. and Breckon, T., Fundamentals of Digital Image Processing: A Practical Approach with Examples in Matlab, Wiley-Blackwell).

[0105] From top to bottom, the following values, ratio between median and mean, median, and standard deviation are plotted over a 90 minute period in Figure 10. This data helps in the formulation of a mathematical model. In this case, a generalized logistic function was fitted using standard regression tools. Using these equations, the time for the water sheen to disappear from the concrete surface of a given concrete section can be predicted, and thus the contractor can know when to move on to the next section and perform finishing. As mentioned before, measurements such as this example can be made using UAV-based sensors, and combined with the ability to automatically collect measurements across the slab over time, can enable contractors to better understand the set time behavior of concrete to ensure proper finishing.

[0106] Example 2 A second concrete was prepared and mixed similarly to Example 1. The mix design was 625 pounds per cubic yard (lbs / yd 3 ) Cement, 1700lbs / yd 3 Stonework, 1450 lbs / yd 3 of sand, 300lbs / yd 3 of water and 4.5 oz / 100 lbs (oz / cwt) of ADVA® 190 cementitious material, high range water reducer (HRWR). A 2 ft x 2 ft x 6 in. slab was produced in the same manner as in Example 1 and monitored over time by a fixed camera (again, envisioned to be replaced by a UAV-based sensor). Unlike in Example 1, the location of the slab was placed in an area where the lighting was variable (e.g., cloud / sun changes). In FIG. 10, the median intensity of each image is shown over time. In this example, there is a poor indication of trends over time. However, texture analysis algorithms (see, for example, Machine Vision, R. Jain, R. Kasturi, B. Schunck, pp. 236-238, incorporated herein by reference) can be used to improve the correlation of the sensor data to the concrete set time values.

[0107] The contrast analysis results are much clearer than those shown using only the median intensity, as shown graphically in Figure 11. Furthermore, the minimum characteristic of the curve can be correlated with the time to initiate the power floating process.

[0108] Example 3 The same concrete specimen observed by the fixed camera in Example 2 above was observed using a near-infrared sensor sensitive to wavelengths in the range of 750-1000 nm. As shown in Figure 12, after approximately 150 minutes, the sensor readings began to decrease linearly. This corresponds to the contrast minimum of the tone co-occurrence matrix in Example 2. As a result, this change in behavior can be used to provide an indication or signal as to when power floating can commence.

[0109] Example 4 Pre-Pour Data The system can be programmed to collect data from each concrete delivery. First, the batch weight, including the amount of cement, aggregate, water and admixtures, is recorded and stored in a database. The batch time is also added to the database. The temperature of the materials can also be added to the database. During delivery, any water or admixtures added to the concrete delivery truck are added to the database. At the time of discharge, the final concrete temperature, current ambient temperature, slump (or slump flow), air content (e.g., from a sensor such as those commercially available under the CiDRA® brand), drum rotations, time since batch, and concrete volume are recorded. All data up to this point can be considered pre-pour data. To simulate this, 29 different concrete mixtures were tested in the laboratory. The same basic mix design was used, including 565 pounds per cubic yard (pcy) ASTM Type I cement, 1700 pcy coarse aggregate, 1425 pcy fine aggregate, and water varying between 260 and 300 pcy water. A high range water reducer (HRWR) (e.g., ADVA® 198 water reducer from GCP Applied Technologies) was used at 4.00 ounces (oz) per 100 pounds of cement (cwt) and an air entrainer (e.g., DAREX® II AEA also available from GCP) was used at 0.4 oz / cwt. All mixtures were mixed using the following protocol: 1) All of the coarse and fine aggregates were placed in the mixer along with 20% water and air entrainer. 2) Mix on high speed for 1 minute. 3) Add the cement and mix again on high speed for 2 minutes. 3) Add the HRWR while continuing to mix for another 2 minutes. 4) Stop the mixer and allow to settle for 3 minutes. 5) Resume mixing on high speed for 2 minutes. 6) Reduce speed and mix for another minute. Finally 7) Stop the mixer and start the test. Of the 48 mixes, 9 mixes did not have AEA, for 8 mixes the cure temperature was 2° C. and for 8 mixes the cure temperature was 38° C. For the remaining 23 mixes the cure temperature was 20° C. Each mix was tested for pre-pour data, slump and air content.

[0110] Post-Pour Data The system also records post-pour data. To simulate this, for each mix tested for pre-pour properties, post-pour properties were also tested, including initial set time, final set time and strength at 1, 3, 7 and 28 days. Initial and final set times were estimated by analyzing the temperature change of a 4 x 8 inch cylinder using typical methods (e.g., www.intrans.iastate.edu / research / documents / research... / CalorimeterReportPhaseIII.pdf). All data was recorded in a database.

[0111] A random forest model was developed to predict the final setting time based on the pre- and post-pouring data. The data was divided into a training set (29 mixes) and a test set (19 mixes). Both sets contained samples with different AEA content, moisture content, and setting temperature. Using a random forest model (see, for example, https: / / en.wikipedia.org / wiki / Random_forest) analysis, the model shown in FIG. 13 was developed, where the x-axis is the actual setting time and the y-axis is the predicted setting time. Contours are plotted with the predicted points for the test set. The model was developed using the pre-pouring properties: slump, air, moisture content, and setting temperature. This setting temperature can be determined using the current and near-future weather conditions at the pouring site. Thus, the setting temperature can be calculated using data from the weather application.

[0112] It should be noted that a variety of methods can be used to develop the model. Once a copy of the data is generated, machine learning techniques can be applied, including supervised learning (e.g., support vector machines, Bayesian methods, random forest methods, etc.) and unsupervised learning (k-means clustering, neural networks, etc.). This is particularly suitable when two or more formulations are considered. Thus, the inputs for the model can be the batch weights of each component in addition to those used in this example.

[0113] The developed models can make set time predictions based on pre-pour information from the concrete load, and these predictions can include slump, air, moisture content and set temperature values ​​or ranges of values.

[0114] The predicted set time values ​​can be compared to the set time of concrete already placed. To adjust the set time of the concrete load, the difference between the predicted set time and the placed set time (based on any other time required before pouring the concrete) can be set as an input to a model that calculates, for example, the appropriate set retarder dosage. These models take the set time adjustment as an input (e.g., another 30 minutes) and output the retarder dosage (e.g., 3 oz / cwt). Concrete producers typically use set retarders to adjust the set time of the mix design (but typically the retarders are only added at the batch plant), however, this general understanding of dosage and set time adjustment exists and the inventors believe is easily adapted to the in-transit / delivery injection method of the present invention. In this manner, the standard model can be used for all mixes, but it is envisioned that as more data is collected (e.g., doses administered and resulting measured set time adjustments), the models resulting from the implementation of the teachings of the present invention can be refined by increasing the amount of data collected. Additionally, additional inputs to the model such as mix design, batch weight, and pre-pour data (e.g., slump, air) can be used. Again, this problem lends itself to solution by machine learning techniques.

[0115] After the set retarder dosage has been calculated, the set retarder can be dosed into the concrete drum to adjust the set time.

[0116] Example 6 The data from Example 5 was reanalyzed using a "difference" method instead of an absolute method. That is, instead of predicting set times based on absolute values ​​of temperature, slump, air, and moisture content, the difference between a particular mix and the reference mix was analyzed. A random forest model was developed using the same method as in Example 5, and the results are shown in Figure 14, where the x-axis is actual set time and the y-axis is predicted set time. Contours are plotted along with the predicted points for the test set. Again, correlations are evident and improve with larger data sets. As in Example 5, the predictive model can be used to determine set times and therefore set time differences.

[0117] Example 7 Same mix design mix protocol as previous example: 1) All coarse and fine aggregates placed in mixer with 20% water and air entrainer. 2) Mix at high speed for 1 minute. 3) Add cement and mix again at high speed for 2 minutes. 3) Add HRWR while continuing to mix for another 2 minutes. 4) Stop mixer and let sit for 3 minutes. 5) Resume mixing at high speed for 2 minutes. 6) Reduce speed and mix for 22 minutes to simulate transportation to job site. 7) Remove 0.25 cubic feet of concrete to simulate partial discharge, and 8) Mix at loading speed for another 15 minutes. Three scenarios were compared: 1) No Recover® addition, hydration set retarder. 2) One dose of Recover® just before mixing after 0.25 cubic feet discharge. 3) Three or four incremental doses (i.e., "dribbled-in") totaling one dose. After mixing, slump, air, strength and set time were measured. Set times were estimated by using the fraction method in analyzing the semi-adiabatic temperature data of concrete. The time corresponding to a temperature rise of 21% of the maximum temperature was used for the initial set and the time corresponding to a temperature rise of 41% of the maximum temperature was used for the final set (see, for example, http: / / www.nrmcaevents.org / ?nav=download&file=541).

[0118] Two different dosage levels were tested. Within each level, both the trickle and single dose had exactly the same total dosage. The first dosage level was tested at 1.0 oz / cwt. For the trickle scenario, four tests were performed with an average of 82 minutes increase in initial set compared to the mix without Recover®. The standard deviation was 24 minutes. For the single dose scenario, three tests were performed with an average of 32 minutes increase in initial set compared to the mix without Recover®. The standard deviation was 27 minutes. Since an earlier, higher dose of Recover would be expected to provide the greatest retardation effect, it is surprising that the gradually increasing dosage schedule provided a more consistent and greater retardation effect.

[0119] Two tests were performed for each scenario at the 4.73 oz / cwt dose. For the low dose scenario, the mean increase in initial set time was 286 minutes, compared to 289 minutes for the single dose scenario. The standard deviations were 7 minutes and 16 minutes, respectively. Thus, at larger doses, the difference between the two scenarios decreases. Thus, depending on the dose required, either the gradually increasing or low dose schedule may be preferred.

[0120] The embodiments disclosed herein are described herein using a limited number of exemplary embodiments that are not intended to limit the scope of the invention(s) otherwise described and claimed herein.

Claims

1. 1. A method for regulating delivery of concrete, comprising: (A) providing at least two delivery trucks, each having a mixer drum containing a concrete load and a processor controlled system for monitoring rheology and at least one set time value or range of values ​​of the concrete load in the drum, wherein the processor: i. accessing at least one stored set time value or range of values ​​assigned to a load of concrete in a mixer drum for delivery to a job site; ii. calculating at least one current set time value or range of values ​​for the load based on the monitored hydration over time; iii. comparing said at least one stored cure time value or range of values ​​with said at least one calculated current cure time value or range of values; and (B) adjusting a current set time value(s) or range(s) of values ​​by introducing a set accelerator, set retarder, or mixtures thereof into at least one of the at least two delivery truck concrete loads to perform or modify a sequential placement, finishing, demolding, framing removal, or compressive strength stage of the concrete load poured from the at least two delivery trucks; The method includes:

2. 2. The method of claim 1, wherein in step (A) at least three delivery trucks (more preferably at least six trucks) are provided, each having a mixer drum containing a concrete load and a processor control system for monitoring rheology and monitoring a set time value or range of values ​​of the concrete load in the drum, the processor performing functions (i), (ii) and (iii) to adjust the stored set time value or range of values ​​or the current set time value or range of values ​​of the concrete.

3. The method of claim 1 , wherein both the stored cure time value or range of values ​​and the current cure time value or range of values ​​are adjusted.

4. The method of claim 1 , wherein the stored set time value or range of values ​​is calculated based on factors including an estimated age of the concrete at the time of pouring.

5. 2. The method of claim 1, wherein the set time value or range of values ​​is selected from time values ​​for: (a) starting finishing; (b) completing finishing; (c) removing framework or forms from the concrete; (d) allowing foot or vehicle traffic over the concrete; (e) releasing tensioned cables from jacks (used in prestressed concrete applications); (f) anchoring or grouting post-tensioned cables (for post-tensioned concrete); or (g) pouring more concrete on top of previously poured concrete.

6. The stored set time values ​​or ranges of values ​​accessed or accessed and adjusted by at least one of the delivery truck processor control systems may be determined based on: (a) ticket information provided by a batch plant that supplied the concrete in the truck mixer drum; (b) a supervisor at a job site where concrete is poured from the truck mixer drum; (c) a temperature sensor placed against a surface of or embedded in concrete poured or placed at the job site or another job site; or (d) a processor receiving data signals from a humidity, moisture, and / or temperature sensor; or (e) a processor monitoring another concrete delivery truck having a processor control system for monitoring the rheology and set time value or range of values ​​of the concrete load.

7. 10. The method of claim 1, further comprising the steps of adjusting the at least one stored cure time value or range of values, and providing a report or indication of the adjustment made to the at least one stored cure time value or range of values.

8. 2. The method of claim 1, wherein the current set time value or range of values ​​is compared to a stored set time value or range of values ​​with respect to at least one factor selected from temperature of the concrete, rate of change of temperature of the concrete, batch volume or mix design of the concrete, adjustment of water or chemical admixtures added within the concrete load, rheology, or other property of the concrete.

9. 2. The method of claim 1, wherein at least one of the concrete loads in one of the at least two delivery trucks is returned concrete, and further wherein comparing a stored set time value or range of values ​​to a current set time value or range of values ​​includes taking into account an age of the concrete from the initial batch of the concrete returned from the job site.

10. 2. The method of claim 1, wherein a first concrete load from a first delivery truck is poured into position and a second concrete load from a second delivery truck is poured on top of the first concrete load while the first concrete load is in a plastic state, the first load and the second load having overlapping set time values ​​or ranges of values.

11. 2. The method of claim 1, wherein the stored set time value or range of values ​​for the pre-delivered and placed concrete at the work site is obtained or derived from a data signal generated by at least one sensor in the nozzle, hose, or other conduit of concrete during deposition or spraying of the concrete through the nozzle, hose, or conduit at the work site.

12. 2. The method of claim 1, wherein a portion of at least one of the concrete loads in the delivery truck is poured at a first job site, and within 15 minutes, more preferably within 10 minutes, of the pouring, a dose of set retarder is introduced into the remaining portion of the concrete load in the delivery truck, and the remaining portion including the dose of set retarder is transported by the delivery truck to a second job site and poured into a predetermined location at the second job site.

13. 2. The method of claim 1, wherein at least five (more preferably at least ten) delivery trucks are provided in accordance with step (A) having concrete loads for which set time values ​​or ranges of values ​​are adjusted in accordance with step (B), said adjustment being performed using calculation of set time values ​​or ranges of values ​​based on signal data obtained or derived from at least one sensor for monitoring the hydration over time of concrete placed at the job site.

14. 1. A method for monitoring set time conditions of a plurality of concrete placements, comprising: Operate at least one aerial drone having at least one sensor for monitoring the hydration of the placed concrete over time to obtain a data signal indicative of hydration. moving the concrete around a plurality of concrete placement locations on the job site; comparing the obtained data signal with previously stored data signals to obtain a set time value or range of values ​​that correlates with hydration data over time obtained from at least one sensor; generating a pictorial or map of multiple concrete placement locations along with set time values ​​or ranges of values, or suggested sequence priorities based on set time values ​​or ranges of values, thereby providing placement instructions suitable for sequential processing for (a) starting finishing, (b) completing finishing, (c) removing framework or forms from said concrete, (d) allowing foot or vehicular traffic over said concrete, (e) releasing tensioned cables from jacks, (f) securing or grouting cables after tensioning, or (g) pouring additional concrete on top of previously poured concrete; The method includes:

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