Method for testing impermeability of mortar based on pnc

Abstract

The application discloses a PNC-based mortar impermeability testing method, and relates to the technical field of building materials.The method comprises the following steps: preparing PNC mortar test piece sets with the same mixing ratio and curing system, and sealing and fixing the test piece sets after being uniformly calibrated to the same water content state to form an impermeability test piece set; performing stable water level difference permeation loading on the impermeability test piece set to form a stable water level difference permeation state, and continuously recording the water outflow of each mortar test piece in the stable water level difference permeation state to form a permeation response time series data set; and constructing a PNC permeation evolution curve and a control permeation evolution curve according to the permeation response time series data set to form a permeation evolution curve set.The application converts the PNC impermeability effect from an overall result into a traceable process section, thereby supporting the description of the evolution law of the impermeability behavior, and improving the stability, repeatability and engineering reference value of the testing conclusion in the time series dimension.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and in particular to a method for testing the impermeability of mortar based on PNC. Background Technology

[0002] With the continuous expansion of the application scope of high-performance concrete and functional admixtures, the mortar impermeability testing technology has gradually shifted from an evaluation method based on final-state permeability indicators to a testing direction that focuses on the characteristics of the permeability process. Related methods have begun to adopt constant water head loading conditions combined with continuous acquisition of outflow rate to dynamically record the permeability behavior of mortar under water action. At the same time, by standardizing specimen preparation conditions and test environment parameters, a more standardized impermeability testing process has been formed.

[0003] However, existing methods for testing the impermeability of mortar mostly focus on the comparative analysis of final-state permeability index and average seepage parameters. They are difficult to reveal the dynamic regulation effect of functional materials on the internal structure of mortar during the permeation process from the perspective of time evolution. In particular, they lack technical means to distinguish different stages of permeation evolution and quantitatively identify the effective time interval of materials, thus limiting the accurate evaluation of the true impermeability contribution mechanism of functional materials. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a PNC-based method for testing the impermeability of mortar, which solves the problem of difficulty in identifying the time intervals during which PNC materials generate effective impermeability at different stages of permeation evolution in the process of mortar impermeability testing.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: This invention provides a method for testing the impermeability of mortar based on PNC (Polymerized Cavity) mortar. The method includes: preparing a set of PNC mortar specimens and a set of control mortar specimens with the same mix proportion and curing regime; uniformly calibrating them to the same moisture content and then sealing and fixing them to form an impermeability performance specimen set; applying a stable water level difference permeation loading to the impermeability performance specimen set to form a stable water level difference permeation state; continuously recording the outflow rate of each mortar specimen under the stable water level difference permeation state to form a permeation response time-series dataset; and constructing PNC permeation evolution curves and control permeation evolution curves based on the permeation response time-series dataset to form a permeation evolution curve set. Each permeability evolution curve in the permeability evolution curve set is divided into three stages according to the characteristics of effluent flow rate change: seepage activation stage, plugging evolution stage, and anti-seepage stability stage, forming a stage-labeled permeability curve set. Based on the stage-labeled permeability curve set, the permeability evolution curves of the PNC mortar specimen set and the control mortar specimen set are compared at the same stage, and the time interval in which the internal structure of the mortar continuously undergoes densification regulation under the participation of PNC is identified as the effective contribution interval of PNC. The permeability in the plugging evolution stage corresponding to the contribution interval is jointly evaluated with the permeability in the anti-seepage stability stage to generate a PNC mortar anti-seepage performance test report.

[0007] As a preferred embodiment of the PNC-based mortar impermeability testing method of the present invention, the steps for preparing a set of PNC mortar specimens and a set of control mortar specimens with the same mix proportion and curing regime are as follows: Weigh the cement, fine aggregate and PNC material, and perform a constant-time water absorption test on the PNC material to obtain the equivalent water absorption. Calculate the effective water-cement ratio of PNC mortar based on the equivalent water absorption. PNC mortar and control mortar were mixed simultaneously according to the effective water-cement ratio, and PNC mortar specimens and control mortar specimens were prepared using the same molding method and the same demolding sequence. PNC mortar specimens and control mortar specimens were placed in the same sealed curing environment, and the moisture supply conditions during the curing period were uniformly controlled to form a set of PNC mortar specimens and a set of control mortar specimens.

[0008] As a preferred embodiment of the PNC-based mortar impermeability testing method of the present invention, the steps for forming the impermeability test specimen set are as follows: Mass measurements were performed on the PNC mortar specimen set and the control mortar specimen set, and an initial mass benchmark was established. Based on the initial quality benchmark, the PNC mortar specimen set and the control mortar specimen set were placed under constant environmental conditions for controlled dehydration, and the quality changes were continuously monitored until the same moisture content was reached. Under the same water content, the non-permeable test surfaces of the PNC mortar specimen set and the control mortar specimen set were sealed and fixed, while the permeable test surfaces were retained to form a permeability resistance specimen set.

[0009] As a preferred embodiment of the PNC-based mortar impermeability testing method of the present invention, the steps for forming a stable water level difference permeability state are as follows: The anti-permeability test specimens are assembled into a permeation clamping structure of uniform specifications, and the permeation test surface is connected and circumferentially sealed to form a permeation clamping state. Establish a height reference between the inlet and outlet ends in the infiltration clamping state, determine the corresponding water level difference, and use the water level difference as the control target. Simultaneously start the water supply and adjust the water supply amount until the water level at the inlet end is stable, forming a stable water level difference infiltration state.

[0010] As a preferred embodiment of the PNC-based mortar impermeability testing method of the present invention, the steps for forming the permeability response time-series dataset are as follows: Under stable water level difference seepage conditions, the outlet of each seepage resistance test specimen is connected to an independent outlet metering channel and a unified time reference is established simultaneously. Under a unified time reference, the outflow volume in each water metering channel is continuously collected at a fixed sampling period, and the outflow rate of each mortar specimen at the corresponding time is calculated to obtain the outflow rate time series. A consistency check is performed on the effluent flow time series and abnormal sampling points are removed to form a seepage response time series dataset.

[0011] As a preferred embodiment of the PNC-based mortar impermeability testing method of the present invention, the steps for constructing the PNC permeability evolution curve are as follows: Based on the effluent flow time series of each PNC mortar specimen in the permeability response time series dataset, the time change rate of effluent flow is calculated, and integral processing is performed in time order to generate a permeability evolution state sequence. The infiltration evolution state sequence is mapped to a unified time base to form an infiltration evolution trajectory; The permeation evolution trajectory within the PNC mortar specimen set was standardized to generate PNC permeation evolution curves.

[0012] As a preferred embodiment of the PNC-based mortar impermeability testing method of the present invention, the steps for forming the permeability evolution curve set are as follows: Structural intrinsic evolution modeling was performed on the effluent flow time series of the control mortar specimen set based on the permeability response time series dataset to generate the permeability evolution trajectory of the control mortar. The control mortar infiltration evolution trajectory was correlated and made continuous with a unified time benchmark to obtain the control infiltration evolution curve; The PNC permeation evolution curves and the control permeation evolution curves were summarized and organized according to a unified time base to form a set of permeation evolution curves.

[0013] As a preferred embodiment of the PNC-based mortar impermeability testing method of the present invention, the step of forming a set of permeability curves is as follows: For each permeation evolution curve in the set of permeation evolution curves, time-varying features are extracted to generate an evolution response sequence; The stage boundary locations are determined based on the changing patterns of the evolutionary response sequence over time. Based on the stage boundary, the permeability evolution curve set is divided into time intervals and labeled with stages, resulting in a stage-labeled permeability curve set including the seepage activation stage, the plugging evolution stage, and the anti-seepage stabilization stage.

[0014] As a preferred embodiment of the PNC-based mortar impermeability testing method of the present invention, the time interval for identifying the continuous densification regulation effect of the mortar internal structure under the participation of PNC is defined as the effective contribution interval of PNC. The steps are as follows. By grouping permeation curves into sets with the same stage type and a unified time reference, the PNC permeation evolution curves and control permeation evolution curves are aligned at the same stage to form a set of permeation curve pairs. Perform persistence of difference discrimination on the PNC permeation evolution curves and control permeation evolution curves within the corresponding stages of the permeation curve set, and identify the set of continuous time intervals in which the permeation evolution differences remain stable; Based on a set of continuous time intervals, the time intervals that reflect the continuous densification regulation effect of PNC on the internal structure of mortar are selected as the effective contribution intervals of PNC.

[0015] As a preferred embodiment of the PNC-based mortar impermeability testing method of the present invention, the steps for generating the PNC mortar impermeability test report are as follows: Extract PNC penetration evolution curve segments corresponding to the effective contribution interval of PNC from the closure evolution stage to form closure evolution evaluation data; Extract control permeability evolution curve segments corresponding to the effective contribution range of PNC from the anti-permeability stabilization stage to form anti-permeability stabilization evaluation data; Joint evaluation data were obtained by combining anti-seepage stability evaluation data and plugging evolution evaluation data; The joint evaluation data were mapped to the corresponding segments of the PNC mortar permeability evolution curve according to the effective contribution interval of PNC and then processed to generate a PNC mortar impermeability test report.

[0016] The beneficial effects of this invention are as follows: by annotating the permeability evolution curve in stages and performing aligned analysis on the permeability evolution behavior of PNC mortar and control mortar under the same stage conditions, it is possible to accurately identify the effective time interval in which the internal structure of mortar continuously undergoes densification regulation under the participation of PNC within a unified time reference and the same permeability stage. This transforms the overall result of PNC anti-permeability effect into a traceable process segment, thereby supporting the characterization of the evolution law of anti-permeability behavior and improving the stability, repeatability and engineering reference value of the test conclusions in the time dimension. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of a PNC-based method for testing the impermeability of mortar.

[0019] Figure 2 A flowchart for forming a set of specimens with impermeability performance.

[0020] Figure 3 A flowchart for forming a set of penetration evolution curves.

[0021] Figure 4 A flowchart for generating a test report on the impermeability of PNC mortar. Detailed Implementation

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0025] Reference Figures 1-4This is one embodiment of the present invention, which provides a method for testing the impermeability of mortar based on PNC, comprising the following steps: S1. Prepare a set of PNC mortar specimens and a set of control mortar specimens with the same mix ratio and curing regime, and calibrate them to the same moisture content before sealing and fixing them to form a set of specimens for impermeability performance.

[0026] S1.1: Weigh the cement, fine aggregate and PNC material, and perform a constant-time water absorption test on the PNC material to obtain the equivalent water absorption. Specifically, cement, fine aggregate, and PNC material were placed in the same weighing environment and weighed sequentially using the same weighing method, with the corresponding mass recorded. The PNC material was placed in a controlled water environment for a constant duration, allowing it to fully contact the water and reach a stable water absorption state within that time. After the constant duration, the surface moisture of the PNC material was removed, and the mass was measured again. By comparing the mass change of the PNC material before and after water absorption, the equivalent water absorption capacity reflecting the water absorption characteristics of the PNC material was obtained.

[0027] It should be noted that PNC material refers to a type of permeable crystalline material that can undergo continuous reaction under water conditions; Constant duration refers to setting a uniform duration for the contact between PNC material and water during the water absorption test of PNC material, and maintaining the same duration in the same batch of tests, so that the water absorption process of PNC material is completed under comparable conditions.

[0028] S1.2: Calculate the effective water-cement ratio of PNC mortar based on the equivalent water absorption; The expression for calculating the effective water-cement ratio of PNC mortar is: ; in, This indicates the effective water-cement ratio of PNC mortar; This indicates the mass of mixing water determined by the initial mix proportion; This indicates the equivalent water absorption of PNC material under constant-time water absorption measurement conditions; This indicates the mass of cement in the mortar.

[0029] It should be noted that the initial mix proportion is determined by selecting a fixed mass ratio of cement to fine aggregate before the start of the experiment, and determining the mass of PNC material to be incorporated and the corresponding mass of mixing water based on the solid mass ratio, thus forming the material mass ratio relationship for mortar specimen preparation.

[0030] S1.3: PNC mortar and control mortar were mixed simultaneously according to the effective water-cement ratio, and PNC mortar specimens and control mortar specimens were prepared using the same molding method and the same demolding sequence. Specifically, according to the effective water-cement ratio, cement, fine aggregate, PNC material, and control mortar material were added to different mixing containers along with mixing water. The PNC mortar and control mortar were mixed synchronously under the same time conditions to achieve a consistent mixing state. The mixed PNC mortar and control mortar were then placed into molding molds of the same specifications and molded using the same vibration method. After molding, they were left to stand under the same environmental conditions and demolded at the same time point to prepare PNC mortar specimens and control mortar specimens with the same molding method and demolding sequence.

[0031] It should be noted that PNC mortar is a mixture obtained by mixing cement, fine aggregate, PNC material and mixing water according to the initial mix proportion; control mortar is a mixture obtained by mixing cement, fine aggregate and mixing water according to the initial mix proportion without adding PNC material.

[0032] S1.4: Place the PNC mortar specimens and the control mortar specimens in the same closed curing environment and uniformly control the moisture replenishment conditions during the curing period to form a set of PNC mortar specimens and a set of control mortar specimens.

[0033] Specifically, PNC mortar specimens and control mortar specimens were placed in the same sealed curing environment, and the moisture conditions in the curing space were uniformly supplied during the curing process, so that the PNC mortar specimens and control mortar specimens were continuously cured under the same humidity conditions until the predetermined curing period was reached, thus forming a set of PNC mortar specimens and a set of control mortar specimens under the same curing conditions.

[0034] S1.5: Perform mass measurements on the PNC mortar specimen set and the control mortar specimen set, and establish an initial mass benchmark; Specifically, based on the PNC mortar specimen set and the control mortar specimen set, the quality of each PNC mortar specimen and each control mortar specimen was measured sequentially, and the corresponding quality status was recorded under the same measurement conditions. The quality measurement results of each PNC mortar specimen and each control mortar specimen were summarized and organized to establish the initial quality benchmarks for the PNC mortar specimen set and the control mortar specimen set.

[0035] S1.6: Based on the initial quality benchmark, the PNC mortar specimen set and the control mortar specimen set were placed under constant environmental conditions for controlled dehydration, and the quality changes were continuously monitored until the same moisture content was reached; Specifically, based on the initial quality benchmark, the quality of the PNC mortar specimen set and the control mortar specimen set were measured and recorded separately. The PNC mortar specimen set and the control mortar specimen set were simultaneously placed in the same constant environmental conditions, allowing the specimens to gradually lose moisture under constant environmental conditions. During the moisture loss process, the quality changes of the PNC mortar specimen set and the control mortar specimen set were continuously recorded at uniform time intervals to form quality change results. When the quality change results reflected that the PNC mortar specimen set and the control mortar specimen set had reached a consistent moisture content, the controlled dehydration process was stopped.

[0036] S1.7: Under the same water content, seal and fix the non-permeable test surfaces of the PNC mortar specimen set and the control mortar specimen set, while retaining the permeable test surfaces to form a permeability resistance specimen set.

[0037] Specifically, after the PNC mortar specimen set and the control mortar specimen set reach the same water content, the outer surface of each mortar specimen is distinguished according to the predetermined permeation direction. The surface corresponding to the predetermined permeation direction is determined as the permeation test surface, and the outer surface other than the permeation test surface is determined as the non-permeation test surface. The non-permeation test surface is continuously covered and circumferentially sealed and fixed so that water can only communicate with the interior of the specimen through the permeation test surface, thus forming a set of impermeability test specimens under the condition of maintaining the same water content.

[0038] The predetermined penetration direction refers to selecting a certain molding end face of the PNC mortar specimen as the water receiving direction connected to the water inlet end during the molding process of the PNC mortar specimen and the control mortar specimen, and determining the direction in which water enters the interior of the specimen from the molding end face as the penetration direction.

[0039] S2. Apply steady-state water level difference permeation loading to the anti-permeability specimen set to form a steady-state water level difference permeation state. Continuously record the outflow rate of each mortar specimen under the steady-state water level difference permeation state to form a permeation response time series dataset.

[0040] S2.1: The anti-permeability test specimens are assembled into a permeation clamping structure of uniform specifications, and the permeation test surface is connected and circumferentially sealed to form a permeation clamping state; Specifically, the permeability resistance test specimens are placed one by one into a permeation clamping structure of uniform specifications, and the permeation test surface of each mortar specimen is aligned with the water inlet channel in the permeation clamping structure. The contact boundary between the permeation test surface and the permeation clamping structure is circumferentially sealed and fixed, so that the permeation test surface and the water inlet channel form a continuous connection, while keeping the permeability resistance test specimens stable in the permeation clamping structure, forming a permeation clamping state.

[0041] S2.2: Establish a height reference between the inlet and outlet ends under the infiltration clamping state, determine the corresponding water level difference, and use the water level difference as the control target to simultaneously start the water supply and adjust the water supply amount until the water level at the inlet end is stable, forming a stable water level difference infiltration state.

[0042] Specifically, in the permeation clamping state, the positions of the inlet and outlet ends in the permeation clamping structure are confirmed respectively, and the relative relationship is established with the water level at the inlet and outlet ends as height references to determine the water level height difference between the inlet and outlet ends; the water level height difference is used as the control target to simultaneously start water supply, so that water enters the interior of the anti-permeability test specimen assembly through the permeation test surface, and the water supply is adjusted during the water supply process to keep the water level at the inlet end stable, so that a stable water level difference permeation state is formed under the condition that the water level height difference remains unchanged during the permeation process.

[0043] S2.3: Under stable water level difference seepage conditions, connect the outlet end of each seepage resistance test specimen to an independent outlet water metering channel and establish a unified time reference simultaneously; Specifically, under the condition that the stable water level difference permeability remains unchanged, the position of the water outlet end of each mortar specimen in the anti-permeability performance specimen set is confirmed one by one, and the water outlet end of each mortar specimen is connected and fixed to the corresponding independent water outlet metering channel in sequence; the starting recording time of each water outlet metering channel is uniformly set so that each water outlet metering channel starts recording the water outlet situation at the same time starting point, thereby realizing the time synchronization of the water outlet behavior of the anti-permeability performance specimen set under the stable water level difference permeability state, and obtaining a unified time benchmark.

[0044] S2.4: Under a unified time reference, the outflow volume in each water metering channel is continuously collected at a fixed sampling period, and the outflow flow rate of each mortar specimen at the corresponding time is calculated to obtain the outflow flow rate time series. Specifically, the same fixed sampling period is set for each water metering channel, and under stable water level difference infiltration conditions, the water volume of each water metering channel is continuously recorded according to the fixed sampling period, so that each sampling period corresponds to a set of water volume record values; the water flow rate of each mortar specimen at the corresponding time is calculated based on the water volume record values ​​corresponding to each sampling time, and the water flow rate of each mortar specimen is arranged in chronological order to obtain the water flow rate time series.

[0045] The expression for calculating the outflow rate of each mortar specimen at the corresponding time is: ; in, Indicates the mortar specimen at the first The outflow rate corresponding to each sampling time; Indicates the water metering channel at the first The volume of water discharged at each sampling time; Indicates the water metering channel at the first The volume of water discharged at each sampling time; This indicates the fixed sampling period between two consecutive samples; Indicates the first determined under a unified time base Each sampling time; Indicates the first determined under a unified time base Each sampling time; This indicates the sampling sequence number, which sequentially numbers the sampling times under a unified time reference.

[0046] S2.5: Perform consistency checks on the effluent flow time series and remove abnormal sampling points to form a permeation response time series dataset.

[0047] Specifically, based on a unified time benchmark, the temporal continuity and record integrity of the effluent flow time series are checked item by item to confirm that the effluent flow corresponding to each adjacent sampling time is continuous in time and there are no missing items; the effluent flow that shows sudden discontinuous changes between the effluent flow corresponding to adjacent sampling times is marked and removed, and the remaining effluent flow time series is sorted in time order to form a seepage response time series dataset.

[0048] S3. Based on the permeation response time series dataset, construct the PNC permeation evolution curve and the control permeation evolution curve respectively to form a permeation evolution curve set.

[0049] S3.1: Based on the time series of effluent flow rate of each PNC mortar specimen in the permeability response time series dataset, calculate the time change rate of effluent flow rate, and perform integral processing in time order to generate the PNC mortar permeability evolution state sequence. Specifically, based on the effluent flow time series of each PNC mortar specimen in the permeability response time series dataset, the effluent flow corresponding to adjacent sampling times is selected sequentially according to a unified time benchmark, and the time change rate of effluent flow is calculated in combination with a fixed sampling period to form a sequence of effluent flow change rates arranged in chronological order. Taking the initial sampling time as the starting point, the effluent flow change rates between each adjacent sampling time are accumulated sequentially within the corresponding continuous time range, and the accumulated effluent flow change rate is converted into a permeability evolution state quantity that reflects the continuous evolution of effluent flow over time. The permeability evolution state quantity is recorded in correspondence with the corresponding sampling time, so that the cumulative evolution process of effluent flow over time unfolds continuously, forming a permeability evolution state sequence.

[0050] It should be noted that continuous time range refers to the time range in the penetration response time series dataset where there are no time gaps, jumps, or interruptions between adjacent sampling moments, based on a unified time reference and a fixed sampling period.

[0051] The expression for calculating the rate of change of water flow over time is: ; in, Indicates the first The rate of change of outflow rate over time at each sampling moment; Indicates the first The outflow rate corresponding to each sampling time.

[0052] S3.2: Correspond the permeation evolution state sequence with a unified time base to form the permeation evolution trajectory of PNC mortar; Specifically, based on the unified time reference established in the permeation response time series dataset, each permeation evolution state quantity in the permeation evolution state sequence is associated with its corresponding sampling time, and arranged in chronological order so that each permeation evolution state quantity is continuously connected along the time axis. This connects the permeation evolution states that were originally recorded discretely according to the sampling time into a continuous evolution process with a clear time sequence, thus forming the PNC mortar permeation evolution trajectory.

[0053] S3.3: Perform uniformization processing on the PNC mortar infiltration evolution trajectory to generate the PNC infiltration evolution curve.

[0054] Specifically, under a unified time reference, the permeation evolution trajectories of PNC mortar are aligned and organized according to the same time sequence, so that the permeation evolution state quantities of different PNC mortar specimens at corresponding times are comparable. At the same time position after alignment, the corresponding permeation evolution state quantities within the PNC mortar specimen set are concentrated and merged into a smooth overall arrangement, so that each permeation evolution trajectory maintains a consistent change rhythm and continuity during the time process. The multiple permeation evolution trajectories scattered within the PNC mortar specimen set are unified and converged into a single PNC permeation evolution curve that can reflect the overall permeation behavior of PNC mortar over time.

[0055] S3.4: Based on the permeability response time series dataset, perform structural intrinsic evolution modeling on the effluent flow time series of the control mortar specimen set to generate the permeability evolution trajectory of the control mortar; Specifically, based on the effluent flow time series of the control mortar specimen set in the infiltration response time series data, the effluent flow time series of each control mortar specimen is synchronously expanded according to a unified time benchmark, while maintaining the continuous relationship within each effluent flow time series; the effluent flow change process of the same control mortar specimen within a continuous time range is correlated as a whole, so that the change pattern of effluent flow over time is continuously expanded on the time axis, and the discrete effluent flow time series in the control mortar specimen set are integrated into the infiltration evolution trajectory of the control mortar.

[0056] S3.5: The infiltration evolution trajectory of the control mortar is correlated and made continuous with a unified time benchmark to obtain the control infiltration evolution curve; Specifically, the trajectory positions corresponding to the changes in effluent flow rate within a continuous time range in the control mortar infiltration evolution trajectory are associated one by one with the sampling times in a unified time reference, and arranged in chronological order to form a continuous correspondence between the control mortar infiltration evolution trajectories on a unified time axis. The positions of the control mortar infiltration evolution trajectories corresponding to the control mortar specimens at the same sampling time are aligned and arranged to ensure that the infiltration evolution trajectories of different control mortar specimens at the same time position have a consistent time reference relationship. The control mortar infiltration evolution trajectories are continuously arranged and converged under a unified time reference to form the control infiltration evolution curve.

[0057] S3.6: Summarize and organize the PNC permeation evolution curves and the control permeation evolution curves according to a unified time base to form a permeation evolution curve set.

[0058] Specifically, the PNC permeation evolution curve and the control permeation evolution curve are aligned one by one according to the same sampling time in a unified time reference, so that the PNC permeation evolution curve and the control permeation evolution curve have a consistent time reference relationship at each time position; the PNC permeation evolution curve and the control permeation evolution curve are arranged side by side in chronological order, so that the two types of permeation evolution curves form a synchronous overall structure under the same time axis, and thus, under the constraint of a unified time reference, the PNC permeation evolution curve and the control permeation evolution curve are jointly organized into a permeation evolution curve set.

[0059] S4. Divide each permeability evolution curve in the permeability evolution curve set into the seepage activation stage, the plugging evolution stage, and the anti-seepage stability stage according to the characteristics of the change in effluent flow rate, and form a stage-labeled permeability curve set.

[0060] S4.1: Extract time-varying features from each permeation evolution curve in the set of permeation evolution curves to generate an evolution response sequence; Specifically, the changes in each permeability evolution curve in the set of permeability evolution curves are read sequentially at continuous time positions along a unified time reference, and the characteristics of water flow change (variation amplitude, change direction and change continuity) are extracted as water flow progresses over time. The permeability evolution curves are then segmented to record the change characteristics corresponding to each time position in the permeability evolution curves in a sequential manner. The change characteristics of the same permeability evolution curve recorded sequentially on the time axis are then linked together according to the original time order, so that the change characteristics unfold continuously over time to form an evolution response sequence.

[0061] S4.2: Identify the time points in the evolution response sequence where the effluent flow rate changes from an initial fluctuating state to a continuously changing state, and from a continuously changing state to a stable changing state, and determine the stage boundary locations. Specifically, the changes in effluent flow rate at each adjacent time point in the evolution response sequence are compared segment by segment. When the evolution response sequence changes from an early state of frequent fluctuations and unstable change direction to a state of consistent and continuous extension, the corresponding time point is identified as the time point where the initial fluctuating state transitions to the continuous change state. Continuing to observe the evolution response sequence in chronological order, when the change in effluent flow rate changes from a state of continuous extension to a state of convergent change amplitude and overall stable trend, the corresponding time point is identified as the time point where the continuous change state transitions to the stable change state. The two time points where the state transition occurs together constitute the stage boundary.

[0062] S4.3: Divide the permeability evolution curve set into time intervals and mark the stages according to the stage boundary positions to obtain a stage-marked permeability curve set including the seepage activation stage, the plugging evolution stage, and the anti-seepage stabilization stage.

[0063] Specifically, each permeability evolution curve in the permeability evolution curve set is segmented according to the stage boundary position, so that each permeability evolution curve is divided into several continuous and non-overlapping time intervals. Based on the change characteristics corresponding to each time interval in the evolution response sequence, the initial time interval is marked as the seepage activation stage, the intermediate continuous time interval is marked as the sealing evolution stage, and the subsequent time interval that tends to be stable is marked as the anti-seepage stability stage. By completing a consistent time interval division and stage labeling for all permeability evolution curves in the permeability evolution curve set, different mortar specimens form a permeability curve set with stage labels including the seepage activation stage, the sealing evolution stage, and the anti-seepage stability stage under a unified time benchmark.

[0064] S5. Based on the stage-labeled permeability curve set, the permeability evolution curves of the PNC mortar specimen set and the control mortar specimen set are compared at the same stage, and the time interval in which the internal structure of the mortar continuously undergoes densification regulation under the participation of PNC is identified as the effective contribution interval of PNC.

[0065] S5.1: The permeability curves are grouped according to the same stage type and unified time reference. The PNC permeability evolution curves are aligned with the control permeability evolution curves at the same stage to form a set of permeability curve pairs. Specifically, based on the stage labels and unified time reference in the set of stage-labeled permeability curves, the PNC permeability evolution curve and the control permeability evolution curve are respectively positioned in stages, so that the PNC permeability evolution curve and the control permeability evolution curve correspond to the same time interval range in the seepage activation stage, the plugging evolution stage and the anti-seepage stabilization stage. Under the constraint of the unified time reference, the PNC permeability evolution curve segments and the control permeability evolution curve segments in the same stage and with the same time interval range are arranged in a one-to-one correspondence, so that the two types of permeability evolution curves form a stable alignment relationship at the same stage and the same time position, forming a set of permeability curve pairs organized according to stage type and time sequence.

[0066] S5.2: Perform a difference persistence judgment on the PNC permeation evolution curves and control permeation evolution curves in the corresponding stages of the permeation curve set, and identify the set of continuous time intervals in which the permeation evolution differences remain stable; Specifically, the relationship between the PNC permeation evolution curve and the control permeation evolution curve in the permeation curve set is recorded hourly along a unified time reference, so that the PNC permeation evolution curve and the control permeation evolution curve form a continuous time correspondence within the stage. Along the time progression direction, the time periods in which the PNC permeation evolution curve and the control permeation evolution curve maintain the same trend of change between adjacent time points without reversal or interruption are identified, and the time periods are continuously connected and organized. Under the same stage, the continuously connected time periods are uniformly summarized, so that each time interval corresponds to the process in which the difference between the PNC permeation evolution curve and the control permeation evolution curve remains stable, forming a continuous time interval set.

[0067] It should be noted that the stability criterion in the difference persistence judgment is the stage labeling of the stage-labeled permeation curve set. Within the stage range with the same stage identifier and continuous time position, the relative change relationship between the PNC permeation evolution curve and the control permeation evolution curve at continuous time position is constrained to be consistent. When the PNC permeation evolution curve and the control permeation evolution curve always maintain the same change relationship in the same direction during the continuous time process and there is no switching, change or interruption of the relative change direction, it is determined that the difference state between the PNC permeation evolution curve and the control permeation evolution curve remains stable within the time range.

[0068] S5.3: Based on the set of continuous time intervals, the time intervals that reflect the continuous densification regulation effect of the internal structure of mortar under the participation of PNC are selected as the effective contribution intervals of PNC.

[0069] Specifically, based on the stage identifiers and time positions corresponding to each continuous time interval in the stage-marked permeability curve set, the continuous time interval set is organized segment by segment to ensure that each continuous time interval is clearly associated with the same stage of change process of the PNC permeability evolution curve and the control permeability evolution curve. Within the sealing evolution stage, time intervals in the continuous time interval set that maintain a continuous difference between the PNC permeability evolution curve and the control permeability evolution curve without stage transition are selected. Continuous time intervals whose time positions do not fall into the sealing evolution stage or that span different stages are excluded. The portions that completely overlap with the sealing evolution stage time intervals in the stage-marked permeability curve set are retained, ensuring that the retained time intervals correspond to the process of continuous densification regulation of the mortar internal structure under the participation of PNC. The retained continuous time intervals are then aggregated into effective PNC contribution intervals.

[0070] S6. Jointly evaluate the permeability in the sealing evolution stage corresponding to the contribution interval and the permeability in the anti-seepage stability stage to generate a PNC mortar anti-seepage performance test report.

[0071] S6.1: Extract the PNC penetration evolution curve segments corresponding to the effective contribution interval of PNC from the closure evolution stage to form closure evolution evaluation data; Specifically, based on the time position corresponding to the effective contribution interval of PNC under a unified time benchmark, PNC permeation evolution curve segments with the same time position are directly extracted from the PNC permeation evolution curves within the blocking evolution stage, so that each extracted PNC permeation evolution curve segment corresponds one-to-one with the effective contribution interval of PNC in terms of time position; the PNC permeation evolution curve segments obtained corresponding to each effective contribution interval of PNC are uniformly organized in chronological order, so that each curve segment remains complete, continuous and comparable within the blocking evolution stage, forming blocking evolution evaluation data.

[0072] S6.2: Extract the control permeability evolution curve segment corresponding to the effective contribution interval of PNC from the anti-permeability stabilization stage to form anti-permeability stabilization evaluation data; Specifically, based on the time position corresponding to the effective contribution interval of PNC under a unified time benchmark, a control permeability evolution curve segment with the same time position is selected from the control permeability evolution curve within the anti-seepage stability stage. This ensures that the selected control permeability evolution curve segment corresponds to the effective contribution interval of PNC in terms of start and end time. The control permeability evolution curve segments selected for each effective contribution interval of PNC are then uniformly organized in chronological order to ensure that each curve segment remains continuous, complete, and comparable within the anti-seepage stability stage, thus forming anti-seepage stability evaluation data.

[0073] S6.3: Jointly analyze the anti-seepage stability evaluation data and the plugging evolution evaluation data to obtain joint evaluation data; Specifically, based on a unified time benchmark, the plugging evolution evaluation data and the seepage resistance stability evaluation data are arranged in a one-to-one correspondence according to the time position corresponding to the effective contribution interval of the PNC, so that the two types of evaluation data form a clear correlation in time position; within the corresponding continuous time interval, the seepage change process reflected by the plugging evolution evaluation data and the seepage maintenance state reflected by the seepage resistance stability evaluation data are compared and organized, so that the plugging evolution stage and the seepage resistance stability stage form a continuous and connected seepage state description within the same time frame; the seepage state descriptions are uniformly collected, so that the plugging evolution evaluation data and the seepage resistance stability evaluation data form a complete stage linkage description in terms of time evolution relationship, resulting in joint evaluation data.

[0074] S6.4: Map the joint evaluation data to the corresponding segments of the PNC mortar permeability evolution curve according to the effective contribution interval of PNC and organize them to generate a PNC mortar impermeability test report.

[0075] Specifically, based on the time position corresponding to the effective contribution interval of PNC under a unified time benchmark, the joint evaluation data is mapped segment by segment to the curve segment with the same time position in the PNC mortar permeability evolution curve, so that each segment of joint evaluation data has a clear correspondence with the curve segment in the PNC mortar permeability evolution curve; according to the chronological order, the mapped joint evaluation data and the PNC mortar permeability evolution curve segments are uniformly organized, so that the relevant information of the sealing evolution stage and the anti-seepage stability stage forms a continuous, complete and traceable description in the PNC mortar permeability evolution curve; the organized joint evaluation data and the corresponding PNC mortar permeability evolution curve segments are collected and arranged to form a PNC mortar anti-seepage performance test report with a clear structure and clear time correlation.

[0076] In summary, this invention, by annotating the permeability evolution curve in stages and performing aligned analysis on the permeability evolution behavior of PNC mortar and control mortar under the same stage conditions, can accurately identify the effective time interval in which the internal structure of mortar continuously undergoes densification regulation under the participation of PNC within a unified time reference and the same permeability stage. This transforms the overall result of PNC anti-permeability effect into a traceable process segment, thereby supporting the characterization of the evolution law of anti-permeability behavior and improving the stability, repeatability and engineering reference value of test conclusions in the time dimension.

[0077] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for testing the impermeability of mortar based on PNC, characterized in that: include, A set of PNC mortar specimens with the same mix ratio and curing regime and a set of control mortar specimens were prepared and uniformly calibrated to the same moisture content before being sealed and fixed to form a set of specimens for impermeability performance. A stable water level difference infiltration loading was applied to the anti-permeability specimen set to form a stable water level difference infiltration state. The outflow rate of each mortar specimen was continuously recorded under the stable water level difference infiltration state to form a time series dataset of infiltration response. Based on the permeation response time-series dataset, PNC permeation evolution curves and control permeation evolution curves were constructed to form a permeation evolution curve set. The steps are as follows. Structural intrinsic evolution modeling was performed on the effluent flow time series of the control mortar specimen set based on the permeability response time series dataset to generate the permeability evolution trajectory of the control mortar. The control mortar infiltration evolution trajectory was correlated and made continuous with a unified time benchmark to obtain the control infiltration evolution curve; The PNC permeation evolution curves and the control permeation evolution curves were compiled and organized according to a unified time base to form a permeation evolution curve set; Each permeability evolution curve in the set is divided into three stages based on its effluent flow rate variation characteristics: seepage activation stage, plugging evolution stage, and anti-seepage stability stage, forming a stage-labeled permeability curve set. The steps are as follows. For each permeation evolution curve in the set of permeation evolution curves, time-varying features are extracted to generate an evolution response sequence; Identify the time points in the evolution response sequence where the effluent flow rate changes from an initial fluctuating state to a continuously changing state, and from a continuously changing state to a stable state, and determine the stage boundary locations. Based on the stage boundary, the permeability evolution curve set is divided into time intervals and stage labels to obtain a stage-labeled permeability curve set including the seepage activation stage, the plugging evolution stage, and the anti-seepage stabilization stage. Based on the stage-annotated permeability curve set, the permeability evolution curves of the PNC mortar specimen set and the control mortar specimen set were compared at the same stage. The time interval in which PNC participated in the continuous densification regulation of the internal structure of the mortar was identified as the effective contribution interval of PNC. The steps are as follows. By grouping permeation curves into sets with the same stage type and a unified time reference, the PNC permeation evolution curves and control permeation evolution curves are aligned at the same stage to form a set of permeation curve pairs. Perform persistence of difference discrimination on the PNC permeation evolution curves and control permeation evolution curves within the corresponding stages of the permeation curve set, and identify the set of continuous time intervals in which the permeation evolution differences remain stable; Based on the set of continuous time intervals, the time intervals that reflect the continuous densification regulation effect of the internal structure of mortar under the participation of PNC are selected as the effective contribution intervals of PNC. The permeability during the plugging evolution stage corresponding to the contribution interval is jointly evaluated with the permeability during the anti-seepage stability stage to generate a test report on the anti-seepage performance of PNC mortar.

2. The method for testing the impermeability of mortar based on PNC as described in claim 1, characterized in that: The steps for preparing a set of PNC mortar specimens with the same mix proportions and curing regime, and a set of control mortar specimens, are as follows. Weigh the cement, fine aggregate and PNC material, and perform a constant-time water absorption test on the PNC material to obtain the equivalent water absorption. Calculate the effective water-cement ratio of PNC mortar based on the equivalent water absorption. PNC mortar and control mortar were mixed simultaneously according to the effective water-cement ratio, and PNC mortar specimens and control mortar specimens were prepared using the same molding method and the same demolding sequence. PNC mortar specimens and control mortar specimens were placed in the same sealed curing environment, and the moisture supply conditions during the curing period were uniformly controlled to form a set of PNC mortar specimens and a set of control mortar specimens.

3. The method for testing the impermeability of mortar based on PNC as described in claim 2, characterized in that: The steps for forming the set of impermeability test specimens are as follows: Mass measurements were performed on the PNC mortar specimen set and the control mortar specimen set, and an initial mass benchmark was established. Based on the initial quality benchmark, the PNC mortar specimen set and the control mortar specimen set were placed under constant environmental conditions for controlled dehydration, and the quality changes were continuously monitored until the same moisture content was reached. Under the same water content, the non-permeable test surfaces of the PNC mortar specimen set and the control mortar specimen set were sealed and fixed, while the permeable test surfaces were retained to form a permeability resistance specimen set.

4. The method for testing the impermeability of mortar based on PNC as described in claim 3, characterized in that: The steps to establish a stable water level difference and permeability are as follows. The anti-permeability test specimens are assembled into a permeation clamping structure of uniform specifications, and the permeation test surface is connected and circumferentially sealed to form a permeation clamping state. Establish a height reference between the inlet and outlet ends in the infiltration clamping state, determine the corresponding water level difference, and use the water level difference as the control target. Simultaneously start the water supply and adjust the water supply amount until the water level at the inlet end is stable, forming a stable water level difference infiltration state.

5. The method for testing the impermeability of mortar based on PNC as described in claim 4, characterized in that: The steps for forming the penetration response time-series dataset are as follows: Under stable water level difference seepage conditions, the outlet of each seepage resistance test specimen is connected to an independent outlet metering channel and a unified time reference is established simultaneously. Under a unified time reference, the outflow volume in each water metering channel is continuously collected at a fixed sampling period, and the outflow rate of each mortar specimen at the corresponding time is calculated to obtain the outflow rate time series. A consistency check is performed on the effluent flow time series and abnormal sampling points are removed to form a seepage response time series dataset.

6. The method for testing the impermeability of mortar based on PNC as described in claim 5, characterized in that: The steps for constructing the PNC penetration evolution curve are as follows: Based on the time series of effluent flow rate of each PNC mortar specimen in the permeability response time series dataset, the time change rate of effluent flow rate is calculated, and integral processing is performed in time order to generate the permeability evolution state sequence of PNC mortar. The permeation evolution state sequence is mapped to a unified time base to form the permeation evolution trajectory of PNC mortar; The permeation evolution trajectory of PNC mortar is standardized to generate a PNC permeation evolution curve.

7. The method for testing the impermeability of mortar based on PNC as described in claim 1, characterized in that: The steps for generating the PNC mortar impermeability test report are as follows: Extract PNC penetration evolution curve segments corresponding to the effective contribution interval of PNC from the closure evolution stage to form closure evolution evaluation data; Extract control permeability evolution curve segments corresponding to the effective contribution range of PNC from the anti-permeability stabilization stage to form anti-permeability stabilization evaluation data; Joint evaluation data were obtained by combining anti-seepage stability evaluation data and plugging evolution evaluation data; The joint evaluation data were mapped to the corresponding segments of the PNC mortar permeability evolution curve according to the effective contribution interval of PNC and then processed to generate a PNC mortar impermeability test report.

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