Rapid quantitative evaluation method and device for flowing property of hydraulic concrete
By measuring the weight of fresh concrete discharged within 7 seconds, combining the level and electronic scales and other devices, the characterization indicators of the flow performance of hydraulic concrete are calculated, and the problem of difficulty in quickly and accurately evaluating the flow performance of hydraulic concrete at the construction site is solved, and the rapid and accurate quantity evaluation and timely monitoring of the flow performance of hydraulic concrete is achieved.
Patent Information
- Application Number
- CN202411703463.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-26
- Publication Date
- 2025-03-04
AI Technical Summary
The prior art is difficult to quickly and accurately evaluate the flow performance of hydraulic concrete at the construction site, especially when the gravel grading is greater than 40cm, the test workload is large and the flow performance during transportation to the pouring process cannot be monitored in a timely manner.
A rapid quantitative evaluation method is provided, by measuring the weight of fresh concrete discharged within 7 seconds, calculating flow performance characterization indicators, and using devices such as level, electronic scale, laser induction timer and weighing machine to achieve accurate evaluation of the flow performance of hydraulic concrete.
The rapid and accurate quantitative evaluation of the flow properties of hydraulic concrete has been achieved, and the problems of large workload and inability to monitor in time by traditional methods have been overcome, and the flow properties of freshly mixed hydraulic concrete can be monitored and adjusted in a timely manner.
Smart Images
Figure CN119555542A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of testing and evaluating the flow performance of hydraulic concrete, and in particular to a method and a device for quickly and quantitatively evaluating the flow performance of hydraulic concrete. Background Art
[0002] In civil engineering construction, in order to ensure the uniformity and density of concrete structure, fresh concrete must have good flow properties. Fresh concrete with poor flow properties will become sticky or clump or bleed, which seriously affects the uniformity and density of concrete during the pouring process and after hardening.
[0003] Therefore, in order to ensure the construction quality of the building project and regulate the concrete flowability at the construction site in real time, it is necessary to conduct a true and accurate quantitative evaluation of the flowability of fresh concrete. At present, the test method for the flowability of ordinary concrete at the construction site usually uses the slump method to determine the expansion and slump of fresh concrete, and then combines the empirical method to comprehensively evaluate the state of the concrete flowability. The slump test method is suitable for ordinary concrete with a crushed stone gradation of less than 40cm, but for fresh hydraulic concrete with a crushed stone gradation of more than 40cm, the slump method can only be used after the crushed stone larger than 40cm needs to be screened out, resulting in an increase in the workload of the flowability test, and it is only tested at the mixing stage in the laboratory, and not before the pouring node.
[0004] Traditional testing and evaluation methods for the flow properties of hydraulic concrete can roughly evaluate the flow properties of concrete, but the evaluation parameters are relatively rough, the testing workload is large, it cannot be quickly tested and quantitatively evaluated, and it can only analyze the flow properties of hydraulic concrete in the mixing and pouring stage. This results in the flow properties of freshly mixed hydraulic concrete from transportation to pouring not being monitored, fed back and adjusted in a timely manner, and thus the flow properties of freshly mixed hydraulic concrete cannot be accurately controlled according to the actual flow state of the freshly mixed hydraulic concrete. Summary of the invention
[0005] In order to quantitatively evaluate the flowability of hydraulic concrete at the construction site and solve the limitations of the flowability test of hydraulic concrete, the present invention provides a rapid quantitative evaluation method and device for the flowability of hydraulic concrete, which can facilitate on-site construction personnel to carry out flowability tests. By measuring the weight of fresh concrete discharged within 7 seconds, the flowability characterization index of fresh concrete is calculated, and the flowability of hydraulic concrete at the construction site is accurately evaluated.
[0006] The present invention achieves the above-mentioned object through the following technical scheme: providing a method for rapid quantitative evaluation of the flow properties of hydraulic concrete, comprising the following steps:
[0007] (1) Debug the test device for the flow properties of hydraulic concrete: Use a level to find a horizontal test surface, place the concrete test device on the horizontal surface, turn on the electronic scale and set it to zero, weigh the concrete bucket to observe the weighing accuracy of the weighing machine, and after confirming that it meets the weighing requirements, fix the concrete silo on the support platform and close the silo baffle;
[0008] (2) Record the weight of the concrete bucket at each stage of the flow performance test: Place the concrete bucket on a weighing machine and set it to zero and peel off the tar. Pour the prepared fresh concrete to be tested into the concrete bucket and stir it evenly. The weighing machine is W1. Adjust the connection position between the upper end of the concrete silo and the high-strength bolts so that the test angle is 60°, and close the concrete silo baffle. Then fill the concrete silo with the fresh concrete to be tested in the concrete bucket. Use a scraper to scrape off the excess concrete on the surface of the silo and vibrate it thoroughly. Collect the scraped concrete and pour it back into the concrete bucket. The weighing machine is W2. After scraping the concrete on the top of the concrete silo and letting it stand for 3 seconds, open the lower baffle of the concrete silo. Start timing when the fresh concrete to be tested leaks out. When the time reaches 7 seconds, immediately close the lower baffle of the concrete silo to prevent the concrete from continuing to fall. Record the displayed value of the weighing machine at this time, W3. After the above experimental test is completed, adjust the test angles of the test device to 45° and 30° respectively, and then repeat the above test steps;
[0009] (3) Based on the weight of each concrete mixture measured in step (2), the quantitative evaluation index of the flowability of hydraulic concrete is calculated: the weight values of the concrete buckets at each stage obtained in each test experiment are combined to calculate the quantitative evaluation index of the flowability of hydraulic concrete at three different test angles of 60°, 45° and 30°;
[0010] The specific calculation formula for calculating the quantitative evaluation index of the flow performance of hydraulic concrete is:
[0011]
[0012] Where, W1 is the weight of the fresh concrete to be tested; W2 is the weight of the concrete in the concrete bucket after the concrete silo is filled and leveled; W3 is the weight of the concrete in the bucket 7s after the concrete silo is unloaded; η θ : It is an evaluation index of the flow performance of hydraulic concrete under the test angle θ, and the value ranges of θ and η are (30°, 45° and 60°), 0<η<1, where the larger the η value, the better the flow performance of concrete.
[0013] The concrete silo in the hydraulic concrete flowability testing device described in step (1) is an open-type chamber with a capacity of 15L and an internal space size of 150mm×150mm×670mm, which is connected to the support platform by bolts and fixed hinge supports.
[0014] The support platform described in step (1) includes five platforms. The first platform is the base of the support platform and is placed on the ground. The free end of the second platform is equipped with a fixed hinge support and is connected to the lower end of the concrete silo. The free ends of the remaining three platforms are equipped with high-strength bolt holes, which can be connected to the upper end of the concrete silo, and the angle between the concrete silo and the horizontal direction can be adjusted to 30°, 45°, and 60° respectively.
[0015] The laser induction timer described in step (1) is fixed at the lower discharge port of the concrete silo, and the accuracy of the laser induction timer is ±0.1s.
[0016] The weighing machine is fixed on the first layer of the supporting plate, and the accuracy of the weighing machine is ±0.5g.
[0017] The concrete bucket is placed on the first support platform, has a capacity of 20L, an internal space size of φ300×283mm, and is located in the unloading direction of the concrete silo. The concrete bucket opening is 10 to 15cm away from the concrete silo opening.
[0018] The device suitable for the method for rapid quantitative evaluation of the flow properties of hydraulic concrete comprises a concrete silo, fresh concrete to be tested, a silo baffle, a laser induction timer, a fixed hinge support, high-strength bolts, a support plate, a concrete bucket, and a weighing machine, wherein the support plate is placed on a horizontal ground, the upper end of the concrete silo is connected to the support plate through high-strength bolts, the lower end of the concrete silo is connected to the support plate through a fixed hinge support, the silo baffle and the laser induction timer are both connected to the lower end of the concrete silo, wherein the silo baffle can slide along the port of the concrete silo, the laser induction timer can start timing after sensing the fresh concrete to be tested during the test, the weighing machine is placed on a bottom layer of the support platform, the concrete bucket is placed on the weighing machine, after the test starts, the fresh concrete to be tested slides into the concrete bucket, and the weighing machine can display its weight change in real time.
[0019] The outstanding advantages of the present invention are:
[0020] The method of the present invention can quantitatively evaluate the flowability of full-grade hydraulic concrete. The method is simple and quick, and overcomes the defects of inaccurate concrete flowability test after high-grade crushed stone is screened out by traditional evaluation methods and increased test workload. The hydraulic concrete flowability evaluation index is obtained by calculation, and the flowability of freshly mixed hydraulic concrete from transportation to pouring can be monitored, fed back and adjusted in time, which has important engineering application value for quantitative evaluation of concrete flowability in on-site construction. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 Schematic diagram of the initial state of the test experiment of the fluidity performance of hydraulic concrete in Example 1.
[0022] Figure 2 This is a schematic diagram of the end state of the test experiment of the fluidity performance of hydraulic concrete in Example 1.
[0023] Figure 3 This is a schematic diagram of the test and evaluation results of the fluidity performance of hydraulic concrete in Example 1.
[0024] Figure numerals: concrete silo 1, fresh concrete to be tested 2, silo baffle 3, laser sensor timer 4, fixed hinge support 5, high-strength bolt 6, support plate 7, concrete bucket 8, weighing machine 9. DETAILED DESCRIPTION
[0025] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.
[0026] Example 1
[0027] The rapid quantitative evaluation method for the flow properties of hydraulic concrete of the present invention comprises the following steps:
[0028] (1) Debug the flowability test device and conduct the test of the flowability of fresh hydraulic concrete: Use a level to find a horizontal test surface, place the concrete test device on the horizontal surface, turn on the electronic scale and set it to zero, weigh the concrete bucket to observe the weighing accuracy of the weighing machine, and after confirming that it meets the weighing requirements, fix the concrete silo on the support platform and close the silo baffle;
[0029] (2) Record the weight of the concrete bucket at each stage of the flow performance test: Place the concrete bucket on a weighing machine and set it to zero and peel it off. Pour the evenly prepared fresh concrete to be tested into the concrete bucket and stir it evenly. The weight is recorded as W1. Adjust the connection position between the upper end of the concrete silo and the high-strength bolts so that the test angle is 60°, and close the concrete silo baffle. Then fill the concrete silo with the fresh concrete to be tested. Use a scraper to scrape off the excess concrete on the surface of the silo and vibrate it thoroughly. Collect the scraped concrete and pour it back into the concrete bucket. The weight is recorded as W2. After scraping the concrete on the top of the concrete silo and letting it stand for 3s, open the lower baffle of the concrete silo. Start timing as the concrete mixture leaks out. When the time reaches 7s, immediately close the lower baffle of the concrete silo to prevent the concrete from continuing to fall. Record the displayed value of the weighing machine at this time, W3. After the above experimental test is completed, adjust the test angles of the test device to 45° and 30° respectively, and then repeat the above test steps;
[0030] (3) Based on the weight of each concrete mixture measured in step (2), the quantitative evaluation index of the flowability of hydraulic concrete is calculated: the weight values of the concrete buckets at each stage obtained in each test experiment are combined to calculate the quantitative evaluation index of the flowability of hydraulic concrete at three different test angles of 60°, 45° and 30°.
[0031] The specific calculation formula for calculating the quantitative evaluation index of the flow performance of hydraulic concrete is:
[0032]
[0033] Wherein, W1 is the weight of the fresh concrete to be tested; W2 is the weight of the concrete in the concrete bucket after the concrete silo is filled and leveled; W3 is the weight of the concrete in the bucket 7s after the concrete silo is unloaded; η θ : is the evaluation index η of the flow performance of hydraulic concrete under the test angle θ, where the value of θ is (30, 45 and 60); the value range of η is: 0<η<1, where the larger the η value, the better the concrete flow performance.
[0034] The above experimental steps were used to conduct multiple groups of experiments, and the experimental results are shown in the following table.
[0035] Table 1 Test weight of fresh concrete at each test angle (kg)
[0036] test W1 W2 W3 <![CDATA[η 30 ]]> 48 11.5 42 <![CDATA[η 45 ]]> 50 13.5 48.4 <![CDATA[η 60 ]]> 51 12.75 48.3
[0037] Note: Due to unavoidable losses during the concrete mixture testing process, W3≠W1.
[0038] Table 2 Quantitative evaluation indexes of flow properties of hydraulic concrete
[0039]
[0040]
[0041] The experimental results show that according to the flowability test method, the flowability evaluation tests of hydraulic concrete were carried out at three test angles of 30°, 45° and 60°. The evaluation indexes of hydraulic concrete flowability at the three test angles were 0.835616, 0.956164 and 0.98069 respectively. The evaluation results are basically consistent with the conclusions of the empirical method, which shows that this method can quickly and quantitatively evaluate the flowability of hydraulic concrete. The three test angles represent different concrete transportation and pouring conditions, but do not affect the flowability of the concrete itself. When evaluating the flowability of concrete of the same batch and the same construction site, it is recommended to compare the flowability evaluation indexes at the same test angle longitudinally.
[0042] Example 2
[0043] Comparison Figure 1 and Figure 2 The device for the rapid quantitative evaluation method of the flow performance of hydraulic concrete of the present invention comprises a concrete silo 1, fresh concrete to be tested 2, a silo baffle 3, a laser induction timer 4, a fixed hinge support 5, a high-strength bolt 6, a support plate 7, a concrete bucket 8, and a weighing machine 9. The specific structure and connection method are as follows:
[0044] The support plate 7 is placed on a horizontal ground, the upper end of the concrete silo 1 is connected to the support plate 7 by a high-strength bolt 6, the lower end of the concrete silo 1 is connected to the support plate 7 by a fixed hinge support 5, the silo baffle 3 and the laser sensing timer 4 are both connected to the lower end of the concrete silo 1, wherein the silo baffle 3 can slide along the port of the concrete silo 1, and the laser sensing timer 4 can start timing after sensing the fresh concrete 2 to be tested during the test. The weighing machine 9 is placed on the bottom layer of the support platform 7, and the concrete bucket 8 is placed on the weighing machine 9. After the test starts, the fresh concrete 2 to be tested slides into the concrete bucket 8, and the weighing machine 9 can display its weight changes in real time.
Claims
1. A rapid quantitative evaluation method for the flow properties of hydraulic concrete, characterized in that: The following steps are involved: (1) Debug the test device for the flow properties of hydraulic concrete: Use a level to find a horizontal test surface, place the concrete test device on the horizontal surface, turn on the electronic scale and set it to zero, weigh the concrete bucket to observe the weighing accuracy of the weighing machine, and after confirming that it meets the weighing requirements, fix the concrete silo on the support platform and close the silo baffle; (2) Record the weight of the concrete bucket at each stage of the flow performance test: Place the concrete bucket on a weighing machine and set it to zero and peel off the tar. Pour the prepared fresh concrete to be tested into the concrete bucket and stir it evenly. The weighing machine is W1. Adjust the connection position between the upper end of the concrete silo and the high-strength bolts so that the test angle is 60°, and close the concrete silo baffle. Then fill the concrete silo with the fresh concrete to be tested in the concrete bucket. Use a scraper to scrape off the excess concrete on the surface of the silo and vibrate it thoroughly. Collect the scraped concrete and pour it back into the concrete bucket. The weighing machine is W2. After scraping the concrete on the top of the concrete silo and letting it stand for 3 seconds, open the lower baffle of the concrete silo. Start timing when the fresh concrete to be tested leaks out. When the time reaches 7 seconds, immediately close the lower baffle of the concrete silo to prevent the concrete from continuing to fall. Record the displayed value of the weighing machine at this time, W3. After the above experimental test is completed, adjust the test angles of the test device to 45° and 30° respectively, and then repeat the above test steps; (3) Based on the weight of each concrete mixture measured in step (2), the quantitative evaluation index of the flowability of hydraulic concrete is calculated: the weight values of the concrete buckets at each stage obtained in each test experiment are combined to calculate the quantitative evaluation index of the flowability of hydraulic concrete at three different test angles of 60°, 45° and 30°; The specific calculation formula for calculating the quantitative evaluation index of the flow performance of hydraulic concrete is: Wherein, W1: is the weight of the fresh concrete to be tested; W2: is the weight of the concrete in the concrete bucket after the concrete silo is filled and leveled; W3: The weight of concrete in the bucket 7s after the concrete silo is unloaded; η θ : It is an evaluation index of the flow performance of hydraulic concrete under the test angle θ, and the value ranges of θ and η are (30°, 45° and 60°), 0<η<1, where the larger the η value, the better the flow performance of concrete.
2. The rapid quantitative evaluation method for the flow properties of hydraulic concrete according to claim 1 is characterized in that: The concrete silo in the hydraulic concrete flowability testing device described in step (1) is an open-type chamber with a capacity of 15L and an internal space size of 150mm×150mm×670mm, which is connected to the support platform by bolts and fixed hinge supports.
3. The rapid quantitative evaluation method for the flow properties of hydraulic concrete according to claim 1 is characterized in that: The support platform described in step (1) includes five platforms. The first platform is the base of the support platform and is placed on the ground. The free end of the second platform is equipped with a fixed hinge support and is connected to the lower end of the concrete silo. The free ends of the remaining three platforms are equipped with high-strength bolt holes, which can be connected to the upper end of the concrete silo, and the angle between the concrete silo and the horizontal direction can be adjusted to 30°, 45°, and 60° respectively.
4. The rapid quantitative evaluation method for the flow properties of hydraulic concrete according to claim 1 is characterized in that: The laser induction timer described in step (1) is fixed at the lower discharge port of the concrete silo, and the accuracy of the laser induction timer is ±0.1s.
5. The rapid quantitative evaluation method for flow properties of hydraulic concrete according to claim 1, characterized in that: The weighing machine is fixed on the first layer of the supporting plate, and the accuracy of the weighing machine is ±0.5g.
6. The rapid quantitative evaluation method for flow properties of hydraulic concrete according to claim 1, characterized in that: The concrete bucket is placed on the first support platform, has a capacity of 20L, an internal space size of φ300×283mm, and is located in the unloading direction of the concrete silo. The concrete bucket opening is 10 to 15cm away from the concrete silo opening.
7. A device suitable for the method for rapid quantitative evaluation of flow properties of hydraulic concrete according to claim 1, characterized in that: It includes a concrete silo, fresh concrete to be tested, a silo baffle, a laser sensing timer, a fixed hinge support, high-strength bolts, a support plate, a concrete bucket and a weighing machine, and is characterized in that the support plate is placed on a horizontal ground, the upper end of the concrete silo is connected to the support plate by a high-strength bolt, the lower end of the concrete silo is connected to the support plate by a fixed hinge support, the silo baffle and the laser sensing timer are both connected to the lower end of the concrete silo, the weighing machine is placed on the bottom layer of the support platform, and the concrete bucket is placed on the weighing machine.