A full-hole slag concrete and a preparation method thereof

Abstract

The application discloses a kind of full hole slag concrete and preparation method thereof, belong to solid waste resource utilization technical field.The application adopts hole slag crushing into mechanism sandstone aggregate, saves the cost of long-distance transportation sandstone aggregate;Mudstone powder and soil curing agent are mixed first and then stand, make the internal structure of soil dense, also increase hydrophobicity, reduce water absorption;The hole slag fine aggregate of high calcium carbonate content is calcined to obtain hole slag quicklime itself has certain cementing property, and can be used as the chemical activity activator of pozzolanic hole slag stone powder, hole slag quicklime and pozzolanic hole slag stone powder are used as cementing material together instead of portland cement as the raw material of concrete.Adopt the anti-cracking reinforcing bar formed by cutting the plant stem such as branch and trunk in hole slag, can be across the two ends of crack in full hole slag concrete, play the role of "bridging", prevent further development of full hole slag concrete crack, and then play the role of anti-cracking and replace steel bar.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization technology, and specifically relates to a full-cavity slag concrete and its preparation method. Background Technology

[0002] The demand for locally sourced concrete materials, such as cement, mineral admixtures, and sand and gravel aggregates, has surged in large-scale engineering construction. However, remote western regions face stringent environmental regulations, have few sand and gravel mines and cement plants, and their rivers are located upstream, resulting in scarce local material resources that cannot meet the needs of large-scale infrastructure projects. Procuring and transporting locally sourced materials from distant locations significantly increases costs. These constraints pose a substantial challenge to the supply of locally sourced concrete materials in remote western regions.

[0003] The construction of railways, highways, and dams in remote western regions involves the excavation of numerous tunnels. Tunnel excavation waste primarily consists of massive rocks, granular stone chips, and excavated soil with a certain moisture content. Its output is large and its composition complex. Currently, the main method for disposing of tunnel excavation waste is to transport it to waste disposal sites for tailings landfill. However, this requires significant manpower and resources and also pollutes the local environment. Therefore, the resource utilization of tunnel excavation waste is considered the best solution to these problems. In recent years, processing tunnel excavation waste into manufactured sand and crushed stone for concrete preparation has become a new method for resource utilization. However, this method faces challenges such as high requirements for rock quality, rendering much of the waste unusable; high content of excavated soil and stone powder reduces the quality of manufactured sand and gravel; unusable excavated soil, stone powder, and stone chips pollute the environment; and the high cost of purchasing bulk materials such as cement and mineral admixtures increases the cost of concrete production.

[0004] In existing technologies, there are precedents for using tunnel muck materials to prepare concrete. However, some technologies still require the addition of silicate cement, and the problem of procuring and transporting ordinary silicate cement over long distances persists. For some extremely remote areas, the cost of concrete production remains high. For example, patent CN112521089A proposes a high-performance concrete and preparation method using all tunnel muck aggregate, and patent CN114276079A proposes a concrete using tunnel muck stone powder admixture and its preparation method. Patent CN115536341A proposes a concrete using all tunnel muck aggregate heated and shaped, and its preparation method. This patent also requires the addition of silicate cement, and the tunnel muck aggregate needs to be dried and heated at 200–300°C during the preparation process, resulting in excessively high energy consumption and costs. In addition, a patent with publication number CN113738387B discloses a method and device for on-site utilization of TBM stone chips inside tunnels. This patent can effectively utilize stone chips on-site inside tunnels, but the method still has the problem that cement still needs to be purchased and transported over long distances, and the soil in the tunnel slag is not treated. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a full-cavity slag concrete, wherein the concrete is composed of the following raw materials in parts by weight:

[0006] 560–800 parts of cave debris fine aggregate, 60–120 parts of fine-grained low-adsorption stone powder, 130–200 parts of cave debris quicklime, 200–300 parts of volcanic ash cave debris stone powder, 10–20 parts of chopped plant straw, 150–180 parts of water, and 720–1100 parts of cave debris coarse aggregate.

[0007] Furthermore, the fine-particle-size, low-adsorption stone powder is obtained by mixing mud-containing stone powder and soil solidifying agent at a mass ratio of 100:2 to 100:5.

[0008] Furthermore, the soil solidifying agent is a mixture of potassium polyacrylate, calcium stearate, and slag quicklime in a mass ratio of 1:1:8.

[0009] Furthermore, the average particle size of the coarse aggregate from the cave slag is 4.75–20 mm, the average particle size of the fine aggregate from the cave slag is 0.15–4.75 mm, and the mudstone powder is the residue at the bottom of the sieve with a particle size of less than 0.15 mm.

[0010] Furthermore, the chopped plant straw is made from tree branches, trunks, and plant stems mixed in with the rubble, which are cut to form crack-resistant reinforcing ribs with a length of 5-10cm.

[0011] On the other hand, the present invention proposes a method for preparing full-cavity slag concrete, the method comprising the following steps:

[0012] The cave debris is crushed and screened to obtain cave debris coarse aggregate, cave debris fine aggregate, mudstone powder, and tree branches, trunks, and plant stems mixed in with the cave debris;

[0013] After mixing mudstone powder with soil stabilizer and letting it stand for 7 to 14 days, low-adsorption stone powder is obtained. The low-adsorption stone powder is then ground to obtain fine-particle-size low-adsorption stone powder.

[0014] High-calcium-carbonate fine aggregates from the slag were screened out and calcined to obtain slag-based quicklime.

[0015] Fine aggregates of volcanic ash with qualified volcanic ash activity were screened from the volcanic ash and then ground to obtain volcanic ash volcanic ash stone powder.

[0016] The branches, trunks, and plant stems mixed in with the rubble were sifted out and cut to obtain short plant stalks;

[0017] The coarse aggregate, fine aggregate, fine-particle-size low-adsorption stone powder, quicklime, pozzolanic stone powder, and chopped plant straw are mixed evenly in proportion to obtain a dry mix. Water is then added and mixed evenly to obtain full-cavity slag concrete.

[0018] Further, the cave debris fine aggregate consists of 560-800 parts, 60-120 parts of fine-particle-size low-adsorption stone powder, 130-200 parts of cave debris quicklime, 200-300 parts of volcanic ash cave debris stone powder, 10-20 parts of chopped plant straw, 150-180 parts of water, and 720-1100 parts of cave debris coarse aggregate.

[0019] Furthermore, the mixing mass ratio of the mudstone powder to the soil solidifier is 100:2 to 100:5, and the soil solidifier is a mixture of potassium polyacrylate, calcium stearate, and slag quicklime with a mass ratio of 1:1:8.

[0020] Furthermore, the high calcium carbonate content cave slag fine aggregate refers to cave slag fine aggregate with a calcium carbonate content higher than 75%.

[0021] Furthermore, the low-adsorption stone powder was ground into fine powder using a ball mill at a speed of 15–18 r / min and a grinding time of 40–60 min.

[0022] The volcanic ash slag fine aggregate was ground using a ball mill at a speed of 22-25 r / min for 60-80 min.

[0023] The beneficial effects of this invention are:

[0024] This invention utilizes cave debris crushed into machine-made sand and gravel aggregate, eliminating the cost of long-distance transportation of sand and gravel aggregate. The mixture of mudstone powder and soil stabilizer is first mixed and then allowed to stand, resulting in a denser soil structure, increased water repellency, and reduced water absorption. The cave debris-based quicklime, obtained by calcining the high-calcium-carbonate fine aggregate, possesses inherent cementing properties and can act as a chemical activator for pozzolanic cave debris powder. The cave debris-based quicklime and pozzolanic cave debris powder together serve as cementing materials, replacing silicate cement as a raw material for concrete. Crack-resistant reinforcing bars formed from the cutting of tree branches and trunks embedded in the cave debris can bridge cracks across both ends of the concrete, preventing further crack development and thus providing crack resistance and serving as a substitute for steel reinforcement. The performance of the tunnel muck concrete produced by this invention is comparable to that of silicate cement concrete. It can make full use of tunnel muck, improve the resource utilization rate of tunnel muck, and solve the problem of long-distance procurement and transportation of cement, coarse aggregate, fine aggregate, mineral admixtures and steel bars required for concrete preparation in remote areas. It is a high-quality green and low-carbon building material, and it also saves the cost of purchasing cement, which greatly reduces the raw material cost of concrete in tunnel projects in remote areas.

[0025] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims, and drawings. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A flowchart of a method for preparing full-cavity slag concrete according to the present invention is shown. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0029] This invention proposes a method for preparing full-cavity slag concrete, such as... Figure 1 As shown, it includes the following steps:

[0030] S1: The cave debris is crushed and screened to obtain cave debris coarse aggregate, cave debris fine aggregate, mudstone powder, and tree branches, trunks, and plant stems mixed in with the cave debris; wherein, the average particle size of the cave debris coarse aggregate is 4.75-20mm, the average particle size of the cave debris fine aggregate is 0.15-4.75mm, and the mudstone powder is the residue at the bottom of the screen with a particle size of less than 0.15mm;

[0031] S2: Mix mudstone powder with soil solidifier and let stand for 7-14 days to obtain low-adsorption stone powder. Grind the low-adsorption stone powder to obtain fine-particle-size low-adsorption stone powder. The soil solidifier can solidify the mudstone powder and significantly reduce its adsorption. The mass ratio of mudstone powder to soil solidifier is 100:2 to 100:5. The soil solidifier is a mixture of potassium polyacrylate, calcium stearate and slag quicklime with a mass ratio of 1:1:8.

[0032] S3: Select fine aggregates with high calcium carbonate content from the slag and calcine them to obtain slag quicklime; among them, fine aggregates with high calcium carbonate content refer to fine aggregates with calcium carbonate content higher than 75%, which can be finely ground by ball milling low-adsorption stone powder, with a ball milling speed of 15-18 r / min and a ball milling time of 40-60 min;

[0033] S4: Select qualified volcanic ash fine aggregate from the slag and grind it to obtain volcanic ash slag powder; specifically, a ball mill can be used to grind the volcanic ash slag fine aggregate, with a ball mill speed of 22-25 r / min and a ball milling time of 60-80 min;

[0034] S5: Select the mixed branches, trunks and plant stems from the cave debris and cut them to obtain short plant straw;

[0035] S6: Mix coarse aggregate, fine aggregate, fine-particle-size low-adsorption stone powder, quicklime from the slag, pozzolanic slag stone powder, and chopped plant straw in a certain proportion to obtain a dry mix. Then add water and mix evenly to obtain full slag concrete. The fine aggregate consists of 560-800 parts, fine-particle-size low-adsorption stone powder of 60-120 parts, quicklime from the slag of 130-200 parts, pozzolanic slag stone powder of 200-300 parts, chopped plant straw of 10-20 parts, water of 150-180 parts, and coarse aggregate of the slag of 720-1100 parts. The chopped plant straw consists of tree branches, trunks, and plant stems mixed in the slag, cut into crack-resistant reinforcing ribs with a length of 5-10 cm.

[0036] Example 1

[0037] A method for preparing full-cavity slag concrete includes the following steps:

[0038] The cave debris was crushed and screened to obtain coarse aggregate with an average particle size of 4.75-20 mm, fine aggregate with an average particle size of 0.15-4.75 mm, mudstone powder with a particle size of less than 0.15 mm, and tree branches, trunks and plant stems mixed in with the cave debris.

[0039] After mixing mudstone powder and soil stabilizer at a mass ratio of 100:5 and letting it stand for 7 days, low-adsorption stone powder is obtained. The soil stabilizer is a mixture of potassium polyacrylate, calcium stearate and quicklime from cave slag at a mass ratio of 1:1:8.

[0040] The low-adsorption stone powder was finely ground using a ball mill to obtain fine-particle-size low-adsorption stone powder; the ball mill speed was 25 r / min and the ball milling time was 60 min.

[0041] Fine aggregates with a calcium carbonate content higher than 75% were screened from the slag and calcined to obtain slag-based quicklime.

[0042] Fine aggregate of volcanic ash slag was screened from the slag and then ground to obtain volcanic ash slag stone powder;

[0043] The branches, trunks, and plant stems mixed in with the rubble were sifted out and cut to obtain short plant stalks;

[0044] Mix 1100 parts of coarse aggregate from cave slag, 590 parts of fine aggregate from cave slag, 120 parts of fine-grained, low-adsorption stone powder, 130 parts of quicklime from cave slag, 200 parts of volcanic ash stone powder from cave slag, and 10 parts of chopped plant straw evenly to obtain a dry mix. Add 150 parts of water to the dry mix and mix evenly to obtain concrete.

[0045] The difference between Example 2 and Example 1 is that the input amounts of each component are as follows: 1040 parts of cave debris coarse aggregate, 580 parts of cave debris fine aggregate, 120 parts of fine-particle-size low-adsorption stone powder, 200 parts of cave debris quicklime, 200 parts of volcanic ash cave debris stone powder, 150 parts of water and 10 parts of chopped plant straw.

[0046] The difference between Example 3 and Example 1 is that the input amounts of each component are as follows: 960 parts of cave debris coarse aggregate, 560 parts of cave debris fine aggregate, 120 parts of fine-particle-size low-adsorption stone powder, 200 parts of cave debris quicklime, 300 parts of volcanic ash cave debris stone powder, 150 parts of water and 10 parts of chopped plant straw.

[0047] The difference between Example 4 and Example 1 is that the input amounts of each component are as follows: 960 parts of cave debris coarse aggregate, 620 parts of cave debris fine aggregate, 60 parts of fine-particle-size low-adsorption stone powder, 200 parts of cave debris quicklime, 300 parts of volcanic ash cave debris stone powder, 150 parts of water and 10 parts of chopped plant straw.

[0048] The difference between Example 5 and Example 1 is that the input amounts of each component are as follows: 720 parts of cave debris coarse aggregate, 800 parts of cave debris fine aggregate, 120 parts of fine-particle-size low-adsorption stone powder, 200 parts of cave debris quicklime, 300 parts of volcanic ash cave debris stone powder, 150 parts of water and 10 parts of chopped plant straw.

[0049] The difference between Example 6 and Example 1 is that the input amounts of each component are as follows: 930 parts of cave slag coarse aggregate, 560 parts of cave slag fine aggregate, 120 parts of fine-particle-size low-adsorption stone powder, 200 parts of cave slag quicklime, 300 parts of volcanic ash cave slag stone powder, 180 parts of water and 10 parts of chopped plant straw.

[0050] The difference between Example 7 and Example 1 is that the mixing ratio of mudstone powder and soil solidifier is 100:2.

[0051] The difference between Comparative Example 1 and Example 1 is that the input amounts of each component are as follows: 1100 parts of cave debris coarse aggregate, 700 parts of cave debris fine aggregate, 120 parts of fine-particle-size low-adsorption stone powder, 130 parts of cave debris quicklime, 100 parts of volcanic ash cave debris stone powder, and 150 parts of water.

[0052] The difference between Comparative Example 2 and Example 1 is that the input amounts of each component are as follows: 1190 parts of cave debris coarse aggregate, 700 parts of cave debris fine aggregate, 120 parts of fine-particle-size low-adsorption stone powder, 130 parts of cave debris quicklime, 150 parts of water and 10 parts of chopped plant straw.

[0053] The difference between Comparative Example 3 and Example 1 is that the input amounts of each component are as follows: 1220 parts of cave debris coarse aggregate, 700 parts of cave debris fine aggregate, 120 parts of fine-particle-size low-adsorption stone powder, 100 parts of volcanic ash cave debris stone powder, 150 parts of water and 10 parts of chopped plant straw.

[0054] The difference between Comparative Example 4 and Example 1 is that the input amounts of each component are as follows: 1210 parts of cave debris coarse aggregate, 700 parts of cave debris fine aggregate, 130 parts of cave debris quicklime, 100 parts of volcanic ash cave debris powder, 150 parts of water and 10 parts of chopped plant straw.

[0055] Comparative Example 5 used quicklime from the slag pit as a soil solidifying agent, with the same dosage as in Example 1, and other conditions remained unchanged, resulting in concrete.

[0056] Comparative Example 6 was prepared by mixing potassium polyacrylate, calcium stearate and quicklime in a mass ratio of 1:1:5. The amount of the mixture was the same as in Example 4, and the other conditions remained unchanged, resulting in concrete.

[0057] Comparative Example 7 was prepared by mixing potassium polyacrylate, calcium stearate and quicklime in a mass ratio of 1:1:10. The amount of the mixture was the same as in Example 4, and the other conditions remained unchanged, resulting in concrete.

[0058] The concrete samples prepared in Examples 1-7 and Comparative Examples 1-7 were subjected to performance tests according to GB / T50082-2009 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete". The results of the determination of the composition of each raw material and the compressive strength of Examples 1-7 and Comparative Examples 1-7 are shown in Table 1:

[0059] Table 1

[0060]

[0061]

[0062] Compared to the comparative examples, the low-carbon caving muck concretes of Examples 1-7 prepared using the formulation of this invention all exhibit a certain compressive strength, which is higher than that of the comparative examples. The caving muck concrete prepared by this invention can be used as a temporary concrete pavement. Although its strength is lower than that of conventional pavement concrete, it is significantly more economical.

[0063] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A type of full-cavity slag concrete, characterized in that, The concrete is composed of the following raw materials in parts by weight: 560–800 parts of cave debris fine aggregate, 60–120 parts of fine-grained low-adsorption stone powder, 130–200 parts of cave debris quicklime, 200–300 parts of volcanic ash cave debris stone powder, 10–20 parts of chopped plant straw, 150–180 parts of water, and 720–1100 parts of cave debris coarse aggregate; The fine-particle-size, low-adsorption stone powder is obtained by mixing mud-containing stone powder and soil solidifying agent at a mass ratio of 100:2 to 100:

5. The soil solidifying agent is a mixture of potassium polyacrylate, calcium stearate, and slag quicklime at a mass ratio of 1:1:

8.

2. The full-cavity slag concrete according to claim 1, characterized in that, The average particle size of the coarse aggregate from the cave slag is 4.75–20 mm, the average particle size of the fine aggregate is 0.15–4.75 mm, and the mudstone powder is the residue at the bottom of the sieve with a particle size of less than 0.15 mm.

3. The full-cavity slag concrete according to claim 1, characterized in that, The chopped plant straw is made from tree branches, trunks, and plant stems mixed in with the rubble in the cave, which are cut into crack-resistant reinforcing ribs with a length of 5 to 10 cm.

4. A method for preparing full-cavity slag concrete, characterized in that, The preparation method includes the following steps: The cave debris is crushed and screened to obtain cave debris coarse aggregate, cave debris fine aggregate, mudstone powder, and tree branches, trunks, and plant stems mixed in with the cave debris; After mixing mudstone powder with soil solidifier, the mixture is left to stand for 7 to 14 days to obtain low-adsorption stone powder. The low-adsorption stone powder is then ground to obtain fine-particle-size low-adsorption stone powder. The mass ratio of mudstone powder to soil solidifier is 100:2 to 100:

5. The soil solidifier is a mixture of potassium polyacrylate, calcium stearate, and slag quicklime with a mass ratio of 1:1:

8. High-calcium-carbonate fine aggregates from the slag were screened out and calcined to obtain slag-based quicklime. Fine aggregates of volcanic ash with qualified volcanic ash activity were screened from the volcanic ash and then ground to obtain volcanic ash volcanic ash stone powder. The branches, trunks, and plant stems mixed in with the rubble were sifted out and cut to obtain short plant stalks; The coarse aggregate, fine aggregate, fine-particle-size low-adsorption stone powder, quicklime, pozzolanic stone powder, and chopped plant straw are mixed evenly in proportion to obtain a dry mix. Water is then added and mixed evenly to obtain full-cavity slag concrete.

5. The method for preparing full-cavity slag concrete according to claim 4, characterized in that, The cave debris fine aggregate consists of 560-800 parts, 60-120 parts of fine-grained, low-adsorption stone powder, 130-200 parts of cave debris quicklime, 200-300 parts of volcanic ash cave debris stone powder, 10-20 parts of chopped plant straw, 150-180 parts of water, and 720-1100 parts of cave debris coarse aggregate.

6. The method for preparing full-cavity slag concrete according to claim 4, characterized in that, The high calcium carbonate content cave slag fine aggregate refers to cave slag fine aggregate with a calcium carbonate content higher than 75%.

7. The method for preparing full-cavity slag concrete according to claim 4, characterized in that, The low-adsorption stone powder was ground into fine powder using a ball mill at a speed of 15-18 r / min and a time of 40-60 min. The volcanic ash slag fine aggregate was ground using a ball mill at a speed of 22-25 r / min for 60-80 min.

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