How to manage the finishing of concrete slabs

Abstract

To provide a finishing control method for a concrete slab capable of easily grasping the timing of finishing work according to required finishing accuracy.SOLUTION: A method for managing a surface finishing work in a concrete slab placing work, comprises the steps of: arranging a soil hardness meter on a surface of concrete at a predetermined measurement position to measure hardness; starting pressing work of the surface of the concrete when the measured hardness reaches a predetermined threshold value and acquiring an elapsed time from a predetermined reference time; and starting finishing work of the surface of the concrete on the basis of the acquired elapsed time and finishing accuracy.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for managing the finishing of a concrete slab. [Background technology]

[0002] Conventionally, the work of pressing down a concrete slab after pouring is generally performed in the following order: (1) leveling (scraping board leveling) → (2) straightedge scraping → (3) leveling (using a mechanical trowel (disc)) → (4) trowel finishing (using a mechanical trowel (propeller)). The order of the precision required for finishing concrete slabs is direct finishing > painted floor finishing base > waterproof base or carpet base (see Figure 4), and the more precision is required for the slab, the more time is required for leveling adjustment, and the more times finishing work with a trowel is repeated.

[0003] The timing of each finishing work varies depending on the setting and hardening speed of the concrete, and understanding the timing is important during construction, but in the past, the timing was determined by the worker's senses, such as the gloss of the concrete surface, the degree to which footprints sink, etc. Therefore, the quality of construction has tended to depend on the skill of the worker.

[0004] Meanwhile, the present patent applicant has already proposed the methods described in Patent Documents 1 and 2 regarding the construction management of concrete slabs. Patent Document 1 measures the hardness of the concrete surface, converts the measured hardness into a concrete penetration resistance value, and determines the concrete setting time based on the converted penetration resistance value. Patent Document 2 measures the penetration resistance value of poured concrete, and finishes the surface of the poured concrete based on the measured penetration resistance value. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-117950 A [Patent Document 2] Patent Publication No. 2021-50469 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the recent decline in the number of construction workers, the number of skilled plasterers is also decreasing, making it difficult to ensure stable construction quality. For this reason, there has been a demand for technology that can easily grasp the timing of finishing work in accordance with the required finishing accuracy, without relying solely on the senses of skilled technicians.

[0007] The present invention has been made in consideration of the above, and aims to provide a method for managing the finishing of concrete slabs, which makes it easy to grasp the timing of finishing work in accordance with the required finishing accuracy. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the objectives, the concrete slab finishing management method of the present invention is a method for managing surface finishing work in concrete slab pouring work, and is characterized by having the steps of placing a soil hardness meter on the surface of the concrete at a predetermined measurement position to measure hardness, starting pressing work on the concrete surface when the measured hardness reaches a predetermined threshold value and acquiring the elapsed time from a predetermined reference time, and then starting finishing work on the concrete surface based on the acquired elapsed time and finishing accuracy.

[0009] Furthermore, another concrete slab finishing management method according to the present invention is characterized in that, in the above-mentioned invention, the soil hardness meter is a Yamanaka type soil hardness meter and uses an index hardness of 25 mm as the threshold value.

[0010] Another concrete slab finishing management method according to the present invention is characterized in that, in the above-mentioned invention, the elapsed time since leveling is obtained. Effect of the Invention

[0011] According to the concrete slab finishing management method of the present invention, which is a method for managing surface finishing work in concrete slab pouring work, the method includes the steps of placing a soil hardness meter on the surface of the concrete at a predetermined measurement position to measure hardness, commencing pressing work on the concrete surface when the measured hardness reaches a predetermined threshold value and acquiring the elapsed time from a predetermined reference time, and then commencing finishing work on the concrete surface based on the acquired elapsed time and finishing accuracy, thereby achieving the effect of making it easy to grasp the timing of the finishing work in accordance with the required finishing accuracy.

[0012] In addition, according to another concrete slab finishing management method of the present invention, the soil hardness meter is a Yamanaka soil hardness meter and uses an index hardness of 25 mm as the threshold value, which has the effect of making it possible to easily grasp the timing of finishing work by utilizing the readings of the Yamanaka soil hardness meter.

[0013] In addition, according to another concrete slab finishing management method of the present invention, the elapsed time since leveling is obtained, thereby achieving the effect of easily grasping the timing of finishing work by utilizing the elapsed time since leveling. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic flow diagram showing an embodiment of a concrete slab finishing management method according to the present invention. [Diagram 2] FIG. 2 is a table showing an example of the timing of pressing the metal iron. [Diagram 3] FIG. 3 is a plan view of a slab showing an example of the measurement position of a soil hardness meter. [Figure 4] FIG. 4 is a table showing a conventional concrete slab finishing method and an example of accuracy measurement. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of a concrete slab finishing management method according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiment.

[0016] (Basic principle of the present invention) First, the basic principle of the present invention will be described. In the present invention, a soil hardness tester is used to measure the hardness of soil, and the state of concrete hardening is grasped, and the timing of trowel pressing is estimated based on this. Until the time of slab pressing, it is easy to repair the measurement marks, so measurements are performed using a soil hardness tester at various locations. Also, measurements are performed at each location where the concrete used and the timing of pouring are different. When it comes to the stage of trowel finishing, it becomes difficult to repair the measurement marks, so the setting and hardening after that is predicted based on the time from smoothing until the soil hardness tester hardness reaches a threshold value (for example, 25 mm). Figure 2 shows the use of the slab to be constructed and the approximate finishing work content. Note that Figure 2 is an approximate guide when ordinary Portland cement is used, and if the type of cement is changed or if it is desired to know the finishing time more precisely, it is desirable to obtain an approximate value by a preliminary test.

[0017] (Soil hardness tester) It is preferable to use a Yamanaka soil hardness tester. When taking measurements, after the concrete bleeding has subsided and moisture is no longer visible at the measurement position, hold the soil hardness tester horizontally and firmly press the cone at the tip of the soil hardness tester against the concrete surface until the brim on the cone is firmly attached. Gently pull out the cone so that the indicator on the body of the soil hardness tester does not move, and read the value on the hardness scale on the body (indicated hardness).

[0018] Since the concrete near the concrete formwork tends to set and harden faster than other areas due to the formwork absorbing moisture from the concrete, the measurement position of the soil hardness meter should be at least 50 cm toward the center (inside) of the slab from the formwork. In principle, it is preferable to only take measurements at the start position of pouring. If pouring is interrupted midway, it is desirable to set a new soil hardness meter measurement position 2 at the position where pouring is to be resumed, in addition to measurement position 1 set at the start position of pouring, as shown in Figure 3, in order to grasp the setting and hardening of subsequent pouring positions.

[0019] It is not necessary to carry out this measurement while the bleeding water is rising. After confirming that the bleeding water has stopped rising, measurements should be taken at 30-minute intervals as a rule. If the nth measurement is the same as the (n-1)th measurement, the measurement interval may be extended to one hour. It is advisable to take five measurements at one time and obtain the average of the three measurements excluding the maximum and minimum values.

[0020] The index hardness measured by the soil hardness meter is the bearing strength (N / mm 2 ), and the bearing strength can be converted to a penetration resistance value. As described in the above Patent Document 1, the relationship between the penetration resistance value for concrete and the bearing strength obtained from a soil hardness meter is that the penetration resistance value of 3.5 N / mm corresponds to the initial setting time. 2 The boundary between the two can be expressed by different regression equations. Penetration resistance value 3.5N / mm 2 In the following cases, the penetration resistance value of the settling = 1.25 x support strength (converted value) + 0.3 (N / mm 2 ) can be used. Penetration resistance value 3.5N / mm 2 If it exceeds this value, the penetration resistance value of the settling = 1.75 x support strength (converted value) + 0.17 (N / mm 2 ) can be used. The penetration resistance value can be calculated by substituting the support strength obtained from the soil hardness meter into the above equation. The concrete setting time can be estimated based on the calculated penetration resistance value. Based on this estimation result, the timing to start pressing work (for example, lining (using a mechanical trowel (disc)) and trowel finishing (using a mechanical trowel (propeller))) can be decided.

[0021] (Specific implementation steps) Next, a specific procedure for carrying out the concrete slab finishing management method according to the present embodiment will be described with reference to FIG.

[0022] As shown in Fig. 1, first, concrete is poured into the construction area (step S1). As shown in Fig. 3, for example, when the planar shape of the construction area is substantially rectangular, the pouring sequence may be such that the position of a corner is set as the starting position for pouring, and pouring proceeds from there in a zigzag pattern in the short side and long side directions.

[0023] Next, measurement of the elapsed time from the smoothing is started (step S2).

[0024] Next, a soil hardness meter is placed on the surface of the concrete at the starting position of pouring to measure the index hardness (step S3). In this way, the concrete hardening condition is grasped. The concrete hardening condition after the starting position of pouring can be estimated from the traceability at the time of pouring, taking into account the elapsed time X.

[0025] Measurements using the soil hardness meter are continued until the reading (index hardness) of the soil hardness meter reaches a preset threshold (e.g., 25 mm) (step S4). When the reading reaches the threshold (Yes in step S4), the work of removing the soil is started using a hand trowel equipped with a disk (step S5). At that time, the time elapsed since leveling is obtained as X (basic time). It is desirable to obtain X for each section to be driven on the day.

[0026] Next, it is determined whether the elapsed time X reaches a preset threshold value (e.g., 1.5X) (step S6). If the elapsed time X reaches the threshold value (Yes in step S6), the finishing work (first time) is performed using a hand trowel equipped with a propeller (step S7).

[0027] Next, it is determined whether the number of times the finishing work has been performed is equal to or greater than the number of times required for the preset slab use (step S8). For slab use that does not particularly require smoothness, such as waterproofing or carpeting, the number of times the finishing work is required can be set to, for example, one time. In this case, it is determined that the number of times the finishing work has been performed is equal to or greater than the number of times required (Yes in step S8), and the finishing work may then be terminated.

[0028] In slab applications that require a certain level of smoothness, such as direct finishing, the number of required finishing operations can be set to, for example, two. If the number of times the finishing operation has been performed is one, it is determined that this is less than the required number of times (No in step S8), and the process returns to step S6. Then, it is determined whether a predetermined threshold value (for example, 2.0X) has been reached. If the result of the determination is that the threshold value has been reached (Yes in step S6), the finishing operation (second time) is performed with a hand trowel (propeller), and then the trowel is removed with a fresno. As a result, the number of times the finishing operation has been performed becomes two, and in step S8, it is determined that this is equal to or greater than the required number of times (two times) (Yes in step S8). Then, the finishing operation may be completed.

[0029] In cases where more accurate direct finishing is required, the number of required finishing operations can be set to, for example, three times. If the number of times the finishing operation has been performed is two, it is determined that this is less than the required number of times (No in step S8), and the process returns to step S6. Then, it is determined whether a predetermined threshold value (for example, 2.5X) has been reached. If the result of the determination is that the threshold value has been reached (Yes in step S6), a riding trowel is used to perform finishing operation (third time) with a metal trowel, and then the trowel is removed with a fresno. As a result, the number of times the finishing operation has been performed is three, and in step S8, it is determined that this is equal to or greater than the required number of times (three times) (Yes in step S8). Then, the finishing operation may be completed.

[0030] According to this embodiment, the timing of pressing operations such as finishing operations can be easily grasped in accordance with the finishing accuracy required for the target slab.

[0031] Also, while skilled workers evaluate the timing based on the luster of the concrete surface and the degree of sinking when footprints are made, in this embodiment, the readings from the soil hardness meter are used directly to evaluate the timing of the work of removing the soil, so even those with relatively little experience can evaluate the work timing with a certain degree of accuracy. Therefore, it is easy to manage the work of finishing with a metal trowel without relying solely on the sense of a skilled worker.

[0032] Note that measurements using a soil hardness tester are not non-destructive, so sinkholes will appear on the concrete surface. However, if the measurement is done during soil preparation, the holes can be repaired immediately.

[0033] Using a soil hardness meter to evaluate the timing of subsequent trowel finishing is undesirable because it makes repairs difficult. Therefore, in this embodiment, some decrease in accuracy is permitted, the time of leveling is set as the reference time, and the time elapsed from the time of leveling until the soil hardness meter reading reaches a threshold value (e.g., 25 mm) is set as the basic time X. Then, as shown in Fig. 2, the time obtained by multiplying this basic time X by a coefficient (1.5, 2.0, 2.5, etc.) set according to the finishing accuracy is predicted as the timing of subsequent trowel finishing.

[0034] As described above, the concrete slab finishing management method of the present invention is a method for managing surface finishing work in concrete slab pouring work, and includes the steps of placing a soil hardness meter on the surface of the concrete at a predetermined measurement position to measure hardness, commencing pressing work on the concrete surface when the measured hardness reaches a predetermined threshold value and acquiring the elapsed time from a predetermined reference time, and then commencing finishing work on the concrete surface based on the acquired elapsed time and finishing accuracy, thereby making it possible to easily grasp the timing of the finishing work in accordance with the required finishing accuracy.

[0035] In addition, according to another concrete slab finishing management method of the present invention, the soil hardness meter is a Yamanaka soil hardness meter and uses an index hardness of 25 mm as the threshold value, so that the timing of the finishing work can be easily grasped using the readings of the Yamanaka soil hardness meter.

[0036] In addition, according to another concrete slab finishing management method of the present invention, the elapsed time since leveling is obtained, so that the timing of finishing work can be easily grasped by utilizing the elapsed time since leveling. [Industrial Applicability]

[0037] As described above, the method for managing the finishing of concrete slabs according to the present invention is useful for managing the construction of concrete slabs, and is particularly suitable for easily understanding the timing of finishing work in accordance with the finishing accuracy required for each slab use.

Claims

1. A method for managing surface finishing work in concrete slab pouring, comprising: A method for managing the finishing of a concrete slab, comprising the steps of: placing a soil hardness meter on the surface of the concrete at a predetermined measurement position to measure hardness; starting pressing work on the concrete surface when the measured hardness reaches a predetermined threshold value and acquiring the elapsed time from a predetermined reference time; and then starting finishing work on the concrete surface based on the acquired elapsed time and finishing accuracy.

2. 2. The method for managing the finishing of a concrete slab according to claim 1, wherein the soil hardness meter is a Yamanaka type soil hardness meter, and an index hardness of 25 mm is used as the threshold value.

3. 3. The method for managing the finishing of a concrete slab according to claim 1, further comprising acquiring the time elapsed since smoothing.

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