Preparation method of low-pressure crushing value hole slag mechanism aggregate based on parent rock mixed matching

Abstract

The application discloses a preparation method of low-pressure crushing value tunnel slag mechanism aggregate based on parent rock mixing and matching, and belongs to the technical field of building materials. The steps are as follows: tunnel and non-tunnel parent rocks of tunnel slag which are not weathered, naturally dried and flat in surface are randomly selected; a rock rebound tester is used to test the rock rebound hardness of the tunnel and non-tunnel parent rocks of tunnel slag; the tunnel and non-tunnel parent rocks of tunnel slag are mixed based on the rock rebound hardness; and a sand and gravel processing yard is used to crush, shape and screen the mixed parent rocks to obtain the low-pressure crushing value tunnel slag mechanism aggregate. The application realizes the preparation of the low-pressure crushing value tunnel slag mechanism aggregate which meets the requirements by using parent rock grading and shaping, and changes the tunnel slag which is abandoned in the past into the tunnel slag for producing the mechanism aggregate, so that the added value of the tunnel slag is greatly improved, and the problems of land occupation and environmental damage of the tunnel slag are solved to a great extent.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and more specifically to a method for preparing low-compression crushing value slag aggregate based on parent rock mixing and matching. Background Technology

[0002] Currently, many transportation engineering projects utilize tunnels to traverse mountains and valleys, generating a large amount of tunnel debris. Disposing of this debris requires significant land acquisition, substantial transportation and maintenance costs, and carries the potential risks of environmental pollution and dam failure. To address these issues and transform this debris into a valuable resource, the current mainstream approach is to process it into manufactured aggregate. However, in most mountainous areas of western China, the crushing value of manufactured aggregate from tunnel debris is relatively high, necessitating optimized preparation methods to reduce this value and ensure its reliability and usability.

[0003] However, existing methods have not effectively solved the problem of excessively high crushing values ​​in cave debris aggregate. For example, utility model patent CN 210146101U, "A Gravel Crushing and Processing Device with High Crushing Ratio and Low Crushing Value," discloses a gravel crushing and processing device with high crushing ratio and low crushing value, but this device is only applicable to the gravel processing field; invention patent CN 117735876A, "A Modified Recycled Aggregate and Its Preparation Method and Production Device," proposes that modification can significantly reduce the crushing value of recycled aggregate, but this method, due to the use of different solution soaking and electric field setting, is not applicable to cave debris parent rock and on-site processing; utility model patent CN 218308287U, "A High-Efficiency Sand and Gravel Shaping Machine," mainly solves the problem of overly cumbersome adjustment of the guard plate in existing vertical shaft impact shaping machines. Patent 215612150U integrates stone shaping, screening, and conveying. However, this patent does not address methods for preparing low-compression-value mine aggregate from slag heaps. Invention patent CN105060753A, "A Particle Shaping Method for Mature Aggregates," uses a roller press for shaping, reducing the needle-like and flaky content of the aggregate. Invention patent CN104844042B, "A Closed-Circuit Cyclic Shaping and Crushing Method for Concrete Aggregates," uses a stone-on-stone method to achieve the shaping effect of the aggregate. These methods do not mention reducing the crushing value of mine aggregate from slag heaps, and only mention the processing technology, without considering the source of the parent rock used in the aggregate processing.

[0004] Therefore, how to adopt a fast, effective, and on-site applicable method to reduce the crushing value of aggregates in slag heaps is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a method for preparing low-compression crushing value slag aggregate based on parent rock mixing and matching.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The preparation method of low-compression crushing value cavern aggregate based on parent rock mixing and matching includes the following steps: (1) Sampling: Randomly select unweathered, naturally air-dried, and flat-surfaced tunnel muck parent rock and non-tunnel muck parent rock; (2) Testing: The rock rebound hardness of the parent rock of tunnel muck and non-tunnel muck was tested using a rock rebound hammer; (3) Mixing: Based on the rock rebound hardness of tunnel muck parent rock and non-tunnel muck parent rock, tunnel muck parent rock and non-tunnel muck parent rock are mixed; Specifically, when the rebound hardness of the tunnel muck parent rock is less than 60 (45 ≤ tunnel muck parent rock), the rebound hardness of the non-tunnel muck parent rock is less than 60, and the mass percentage of the non-tunnel muck parent rock is 50%~80%, with the remainder being tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is less than 70 (60 ≤ tunnel muck parent rock), the mass percentage of the non-tunnel muck parent rock is 40%~70%, with the remainder being tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is less than 80 (70 ≤ tunnel muck parent rock), the mass percentage of the non-tunnel muck parent rock is 30%~60%, with the remainder being tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is ≥80 (80 ≤ tunnel muck parent rock), the mass percentage of the non-tunnel muck parent rock is 20%~50%, with the remainder being tunnel muck parent rock. When the rebound hardness of the tunnel muck parent rock is 60 ≤ < 70; when the rebound hardness of the non-tunnel muck parent rock is 60 ≤ < 70, the mass percentage of the non-tunnel muck parent rock is 40%~70, and the remainder is tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is 70 ≤ < 80, the mass percentage of the non-tunnel muck parent rock is 30%~60%, and the remainder is tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is ≥ 80, the mass percentage of the non-tunnel muck parent rock is 20%~50%, and the remainder is tunnel muck parent rock. When the rebound hardness of the tunnel muck parent rock is less than or equal to 70, and the rebound hardness of the non-tunnel muck parent rock is less than or equal to 80, the mass percentage of the non-tunnel muck parent rock is 20% to 50%, and the remainder is tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is greater than or equal to 80, the mass percentage of the non-tunnel muck parent rock is 10% to 40%, and the remainder is tunnel muck parent rock. When the rock hardness of the tunnel muck parent rock is ≥80, the rock rebound hardness of the non-tunnel muck parent rock is ≥80, the mass ratio of the non-tunnel muck parent rock is 0%~40%, and the rest is tunnel muck parent rock. (4) Preparation: The mixed parent rock is crushed, shaped and screened by a sand and gravel processing plant to obtain low crushing value cave slag aggregate.

[0008] Furthermore, before sampling in step (1), the state and size of the parent rock must be observed, and multiple samples are randomly selected to form an aggregate of parent rock samples. The parent rock samples are selected as unweathered, naturally air-dried, with flat surfaces and length, width and height all greater than 10cm.

[0009] The beneficial effects of adopting the above-mentioned further technical solutions are as follows: the above solutions clarify that the parent rock should be unweathered, naturally air-dried, with a flat surface and a length, width and height of more than 10cm, thereby reducing the sample preparation process during the rebound hardness test, and randomly selecting multiple samples based on probability statistics makes the sampling more representative.

[0010] Furthermore, the parent rock of the tunnel slag in step (1) is at least one of limestone slag, dolomite slag, granite slag, diorite slag, basalt slag, quartz sandstone slag, and gneiss slag; The parent rock is at least one of the following: granite mine parent rock, diorite mine parent rock, basalt mine parent rock, quartz sandstone mine parent rock, granite riverbed material, and diorite riverbed material parent rock.

[0011] Furthermore, the rock rebound hardness test method in step (2) is as follows: Nine measuring points were uniformly selected on the surface of a single parent rock to be tested; each measuring point was tested three times, and the maximum value was taken as the rock rebound hardness of that measuring point; the test results of the rebound hardness R of a single parent rock are shown in Equation (1): R = (R1 + R2 + ... + R9) / 9 (1) In the formula: R —The rebound hardness of a single parent rock is calculated and rounded to the nearest integer. R 1—Maximum rock rebound hardness in 3 repeated rebounds at measuring point 1; R 2—Maximum rock rebound hardness during three repeated rebounds at measuring point two; … R 9—Maximum rock rebound hardness in three repeated rebounds at measuring point nine; The rebound hardness R of multiple parent rock aggregates n The test results are calculated according to formula (2): R n =(R 11 +R 12 +…+R 1n ) / n(2) In the formula: R n —The rebound hardness of rocks from multiple parent rock aggregates is calculated and rounded to the nearest integer. R 11 —The first parent rock's rebound hardness; R 12 —The second parent rock's rebound hardness; … R 1n —The rebound hardness of the nth parent rock.

[0012] The beneficial effects of adopting the above-mentioned further technical solution are as follows: The above solution selects nine measuring points evenly on the surface of the parent rock, with three points in each row at the top, middle and bottom, which can achieve full coverage of the parent rock test area and make the test results more accurate; a single measuring point is repeatedly rebounded 3 times, and the maximum value is taken as the rock rebound hardness of the measuring point, which can quickly and accurately obtain the rock rebound hardness of the parent rock.

[0013] Furthermore, the shaping described in step (4) includes coarse aggregate shaping and fine aggregate shaping.

[0014] Furthermore, the coarse aggregate shaping is performed using a vertical shaft impact shaping machine and / or a vertical shaping machine; The fine aggregate shaping is carried out using a vertical roller mill shaping machine and / or a disc mill shaping machine.

[0015] Furthermore, the evaluation method for low-compression crushing value slag aggregate in step (4) is as follows: When the crushing index of coarse aggregate is ≤6% and the crushing index of fine aggregate is ≤15%, the prepared low crushing value slag aggregate is classified as Class I. When 6% < coarse aggregate crushing index ≤ 9% and fine aggregate crushing index ≤ 20%, or when coarse aggregate crushing index ≤ 9% and 15% < fine aggregate crushing index ≤ 20%, the prepared low-crushing-value slag aggregate is classified as Class II. When 9% < coarse aggregate crushing index ≤ 12% and fine aggregate crushing index ≤ 25%, or when coarse aggregate crushing index ≤ 12% and 20% < fine aggregate crushing index ≤ 25%, the prepared low-crushing-value slag aggregate is classified as Class III.

[0016] The beneficial effects of adopting the above-mentioned further technical solutions are as follows: an innovative classification grade of low-compression crushing value slag aggregate products based on the technical requirements of coarse and fine aggregate indicators is proposed, which can provide a reference for the workability and mechanical properties of concrete with different structures.

[0017] The beneficial effects of this invention are as follows: 1. Improving the accuracy of cave debris testing based on probability statistics and testing procedures: This invention uses multiple samples to form a collection of cave debris specimens. Based on the probability statistics evaluation method, the fluctuation performance of cave debris can be homogenized, thereby ensuring the accuracy of the rock rebound hardness test results of cave debris. In addition, nine measuring points are evenly selected on the surface of the parent rock. Each measuring point is repeatedly rebounded 3 times and the maximum value is taken as the rock rebound hardness of that measuring point. This can achieve full coverage of the parent rock testing area and the test results are more accurate.

[0018] 2. Lower crushing value of tunnel slag aggregate based on parent rock mixing and matching technology: This invention proposes for the first time the mixing ratio of tunnel slag parent rock with different rock rebound hardness and other types of parent rock. This mixing and matching can ensure that the prepared product is a tunnel slag aggregate with low crushing value.

[0019] 3. Better matching of concrete performance requirements based on the crushing value classification of slag aggregate: This invention proposes a classification grade of low crushing value slag aggregate products based on the technical requirements of coarse and fine aggregate indicators. According to the concrete performance requirements of different structural parts, the matching relationship between different grades of low crushing value slag aggregate and concrete workability and mechanical properties can be established, providing a reference for the selection of slag aggregates for different types of concrete.

[0020] 4. Achieving low-value, high-utilization, low-carbon, and environmentally friendly use of cave slag: This invention uses parent rock grading, optimization, and shaping to prepare low-compression-value cave slag aggregate that meets the requirements. It transforms cave slag, which was previously discarded, into cave slag used to produce machine-made aggregate, greatly increasing the added value of cave slag and largely solving the problems of land occupation and environmental damage caused by cave slag. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1 Using limestone tunnel slag and granite mine parent rock as research objects, low-compression crushing value tunnel slag mechanical aggregate was prepared based on parent rock mixing and matching.

[0023] (1) Sampling: 20 limestone tunnel slag parent rocks and 20 granite mine parent rocks were randomly selected to form sample aggregates. The parent rock samples were selected as unweathered, naturally air-dried, with flat surfaces and length, width and height all greater than 10cm. (2) Testing: The rock rebound hardness of the parent rock was quickly tested using a rock rebound hammer. Nine test points were evenly selected on the surface of the parent rock, with three points in each row at the top, middle and bottom. Each test point was rebounded three times, and the maximum value was taken as the rock rebound hardness of that test point. The test results showed that the rebound hardness of limestone tunnel slag was 75, and the rebound hardness of granite mine parent rock was 82. (3) Mixing: Based on the rock rebound hardness of limestone tunnel slag parent rock and granite mine parent rock, limestone tunnel slag parent rock and granite mine parent rock are mixed, with limestone tunnel slag accounting for 70% by mass and granite mine parent rock accounting for 30% by mass.

[0024] (4) Preparation: The mixed parent rock was crushed, shaped, and screened at a sand and gravel processing plant. The coarse aggregate was shaped using a vertical shaft impact shaper, and the fine aggregate was shaped using a vertical roller mill. After grading, low-crushing-value mine aggregate was obtained. The crushing value test results of the prepared mine aggregate are shown in Table 1.

[0025] Table 1. Test results of crushing value of machine-made aggregate

[0026] As can be seen from Example 1 and Table 1, the rock rebound hardness of limestone quarry and granite mine is 75 and 82, respectively, and the mixing ratio is 70% and 30%, respectively. The low-compression-value quarry quarry aggregate product is classified as Class I, indicating that Class I low-compression-value quarry quarry aggregate product can be prepared by using mixing and matching.

[0027] Example 2 Using gneiss tunnel muck and granite riverbed material as parent rocks, low-compression crushing value tunnel muck mechanical aggregate was prepared based on the mixing and matching of parent rocks.

[0028] (1) Sampling: Randomly select 15 gneiss tunnel slag parent rocks and 15 granite riverbed material parent rocks to form sample aggregates. The parent rock samples should be unweathered, naturally air-dried, have a flat surface, and have a length, width and height of more than 10cm. (2) Testing: The rock rebound hardness of the parent rock was quickly tested using a rock rebound hammer. Nine test points were evenly selected on the surface of the parent rock, with three points in each row at the top, middle and bottom. Each test point was rebounded three times, and the maximum value was taken as the rock rebound hardness of that test point. The test results showed that the rebound hardness of the granite tunnel slag was 65, and the rebound hardness of the granite riverbed material parent rock was 75. (3) Mixing: Based on the rock rebound hardness of the granite tunnel debris and the granite riverbed material parent rock, the granite tunnel debris and the granite riverbed material parent rock are mixed, with the granite tunnel debris accounting for 60% by mass and the granite riverbed material parent rock accounting for 40% by mass.

[0029] (4) Preparation: The mixed parent rock was crushed, shaped, and screened at a sand and gravel processing plant. The coarse aggregate was shaped using a vertical shaft impact shaper, and the fine aggregate was shaped using a vertical roller mill. After grading, low-compression-value mine aggregate was obtained. The test results of the crushing value of the prepared mine aggregate are shown in Table 2.

[0030] Table 2 Results of Crushing Value Test for Mechanized Aggregates

[0031] As can be seen from Examples 2 and 2, the rock rebound hardness of gneiss quarry slag and granite riverbed material are 65 and 75, respectively, and the mixing ratios are 60% and 40%, respectively. The low-compression-value quarry slag machine aggregate product is classified as Class III, indicating that Class III low-compression-value quarry slag machine aggregate products can be prepared by using mixing and matching.

[0032] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing low-compression crushing value cavitation aggregate based on parent rock mixing and matching, characterized in that, Includes the following steps: (1) Sampling: Randomly select unweathered, naturally air-dried, and flat-surfaced tunnel muck parent rock and non-tunnel muck parent rock; (2) Testing: The rock rebound hardness of the parent rock of tunnel muck and non-tunnel muck was tested using a rock rebound hammer; (3) Mixing: Based on the rock rebound hardness of tunnel muck parent rock and non-tunnel muck parent rock, tunnel muck parent rock and non-tunnel muck parent rock are mixed; Specifically, when the rebound hardness of the tunnel muck parent rock is less than 60 (45 ≤ tunnel muck parent rock), the rebound hardness of the non-tunnel muck parent rock is less than 60, and the mass percentage of the non-tunnel muck parent rock is 50%~80%, with the remainder being tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is less than 70 (60 ≤ tunnel muck parent rock), the mass percentage of the non-tunnel muck parent rock is 40%~70%, with the remainder being tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is less than 80 (70 ≤ tunnel muck parent rock), the mass percentage of the non-tunnel muck parent rock is 30%~60%, with the remainder being tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is ≥80 (80 ≤ tunnel muck parent rock), the mass percentage of the non-tunnel muck parent rock is 20%~50%, with the remainder being tunnel muck parent rock. When the rebound hardness of the tunnel muck parent rock is 60 ≤ < 70; when the rebound hardness of the non-tunnel muck parent rock is 60 ≤ < 70, the mass percentage of the non-tunnel muck parent rock is 40%~70, and the remainder is tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is 70 ≤ < 80, the mass percentage of the non-tunnel muck parent rock is 30%~60%, and the remainder is tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is ≥ 80, the mass percentage of the non-tunnel muck parent rock is 20%~50%, and the remainder is tunnel muck parent rock. When the rebound hardness of the tunnel muck parent rock is less than or equal to 70, and the rebound hardness of the non-tunnel muck parent rock is less than or equal to 80, the mass percentage of the non-tunnel muck parent rock is 20% to 50%, and the remainder is tunnel muck parent rock; when the rebound hardness of the non-tunnel muck parent rock is greater than or equal to 80, the mass percentage of the non-tunnel muck parent rock is 10% to 40%, and the remainder is tunnel muck parent rock. When the rock hardness of the tunnel muck parent rock is ≥80, the rock rebound hardness of the non-tunnel muck parent rock is ≥80, the mass ratio of the non-tunnel muck parent rock is 0%~40%, and the rest is tunnel muck parent rock. (4) Preparation: The mixed parent rock is crushed, shaped and screened by a sand and gravel processing plant, and the undersize material is taken to obtain the low crushing value of the cave slag aggregate.

2. The method for preparing low-compression crushing value slag aggregate based on parent rock mixing and matching according to claim 1, characterized in that, Before taking samples in step (1), the state and size of the parent rock must be observed. Multiple samples are randomly selected to form an aggregate of parent rock samples. The parent rock samples are selected as unweathered, naturally air-dried, with flat surfaces and length, width and height all greater than 10cm.

3. The method for preparing low-compression crushing value slag aggregate based on parent rock mixing and matching according to claim 1 or 2, characterized in that, The parent rock of the tunnel muck in step (1) is at least one of limestone muck, dolomite muck, granite muck, diorite muck, basalt muck, quartz sandstone muck, and gneiss muck; The parent rock is at least one of the following: granite mine parent rock, diorite mine parent rock, basalt mine parent rock, quartz sandstone mine parent rock, granite riverbed material, and diorite riverbed material parent rock.

4. The method for preparing low-compression crushing value cavitation aggregate based on parent rock mixing and matching according to claim 1, characterized in that, The rock rebound hardness test method in step (2) is as follows: Nine measuring points were uniformly selected on the surface of a single parent rock to be tested; each measuring point was tested three times, and the maximum value was taken as the rock rebound hardness of that measuring point; the test results of the rebound hardness R of a single parent rock are shown in Equation (1): R = (R1 + R2 + ... + R9) / 9 (1) In the formula: R —The rebound hardness of a single parent rock is calculated and rounded to the nearest integer. R 1—Maximum rock rebound hardness in 3 repeated rebounds at measuring point 1; R 2—Maximum rock rebound hardness during three repeated rebounds at measuring point two; … R 9—Maximum rock rebound hardness in three repeated rebounds at measuring point nine; The rebound hardness R of multiple parent rock aggregates n The test results are calculated according to formula (2): R n =(R 11 +R 12 +…+R 1n ) / n(2) In the formula: R n —The rebound hardness of rocks from multiple parent rock aggregates is calculated and rounded to the nearest integer. R 11 —The first parent rock's rebound hardness; R 12 —The second parent rock's rebound hardness; … R 1n —The rebound hardness of the nth parent rock.

5. The method for preparing low-compression crushing value slag aggregate based on parent rock mixing and matching according to claim 1, characterized in that, The shaping described in step (4) includes coarse aggregate shaping and fine aggregate shaping.

6. The method for preparing low-compression crushing value slag aggregate based on parent rock mixing and matching according to claim 5, characterized in that, The coarse aggregate shaping is performed using a vertical shaft impact shaping machine and / or a vertical shaping machine; The fine aggregate shaping is carried out using a vertical roller mill shaping machine and / or a disc mill shaping machine.

7. The method for preparing low-compression crushing value cavitation aggregate based on parent rock mixing and matching according to claim 1, characterized in that, The evaluation method for low-compression crushing value slag aggregate in step (4) is as follows: When the crushing index of coarse aggregate is ≤6% and the crushing index of fine aggregate is ≤15%, the prepared low crushing value slag aggregate is classified as Class I. When 6% < coarse aggregate crushing index ≤ 9% and fine aggregate crushing index ≤ 20%, or when coarse aggregate crushing index ≤ 9% and 15% < fine aggregate crushing index ≤ 20%, the prepared low-crushing-value slag aggregate is classified as Class II. When 9% < coarse aggregate crushing index ≤ 12% and fine aggregate crushing index ≤ 25%, or when coarse aggregate crushing index ≤ 12% and 20% < fine aggregate crushing index ≤ 25%, the prepared low-crushing-value slag aggregate is classified as Class III.

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