Fiber reinforced industrial waste residue-based curing agent as well as preparation method and application thereof

Abstract

The invention provides a fiber reinforced industrial waste residue based curing agent, which relates to the technical field of curing agents, and comprises the following components by weight: 5-12% of fly ash, 4-7% of blast furnace slag, 2-5% of steel slag powder, 3-8% of water glass, and 0.2-0.6% of palm fiber. The invention also provides a preparation method and application of the fiber-reinforced industrial waste residue-based curing agent. Industrial waste residues (fly ash, steel slag powder and the like are mixed according to a certain proportion) are utilized, the physical and mechanical properties of soft soil are improved through an alkali (water glass) excitation reaction, meanwhile, a certain amount of plant fibers (palm fibers) with a certain length are doped into the mixed soil, and the unconfined compressive strength and the splitting tensile strength of the soil can be enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of curing agents, in particular to a fiber-reinforced industrial waste residue-based curing agent and a preparation method and application thereof. Background Art

[0002] Roadbed filling projects require a large amount of soil, and heavy-load roads have high requirements for the bearing capacity of the roadbed. The soil conditions in areas such as soft soil, expansive soil, and collapsible loess are poor, and the mechanical properties after compaction do not meet the requirements of the standard indicators. The application of soil solidifiers can effectively improve the bearing and shear capacity of the soil. However, the production of traditional solidifiers (similar to cement, etc.) has high carbon emissions, and the pure solidifier addition method is not effective in improving soft soil. How to effectively reduce carbon emissions and achieve environmentally friendly and economical reinforcement of soft soil has become the key. Summary of the invention

[0003] In view of the above-mentioned prior art, the present invention proposes a fiber-reinforced industrial waste residue-based curing agent and its preparation method and application to solve the problems of high carbon emissions and poor effect of improving soft soil in the production of traditional curing agents. The present invention reuses industrial waste residues, mixes them with alkali-activated materials such as water glass, and adds a certain proportion of palm fiber to compositely improve the physical and mechanical properties of soft soil and enhance the compression and shear resistance of reinforced soil.

[0004] The invention provides a fiber-reinforced industrial waste slag-based curing agent, which comprises the following components by weight percentage: 5%-12% fly ash, 4%-7% blast furnace slag, 2%-5% steel slag powder, 3%-8% water glass, and 0.2%-0.6% palm fiber.

[0005] Preferably, in the water glass, the molar ratio of silicon dioxide to sodium oxide is 2.5-4.

[0006] Preferably, the length of the palm fiber is 5-12 mm.

[0007] The present invention also provides a method for preparing a fiber-reinforced industrial waste residue-based curing agent, comprising the following steps:

[0008] Step 1: Weigh 5%-12% of fly ash, 4%-7% of blast furnace slag, and 2%-5% of steel slag powder, and mix them thoroughly for 30 minutes to obtain a mixture;

[0009] Step 2: adding 3%-8% of water glass to the mixture, and continuing stirring in a mixer for 20 minutes to obtain a mixture; in the water glass, the molar ratio of silicon dioxide to sodium oxide is 2.5-4;

[0010] Step 3: chop the palm fiber into pieces of 5-12 mm in length, add 0.2%-0.6% by weight to the stirred substance, control the amount of palm fiber added per unit time to not exceed 0.01% / min to prevent the palm fiber from agglomerating, and continue stirring for 30 minutes after the palm fiber is added to obtain a fiber-reinforced industrial waste residue-based curing agent.

[0011] The present invention also provides the use of the fiber-reinforced industrial waste residue-based curing agent or the prepared fiber-reinforced industrial waste residue-based curing agent in treating slightly expansive soil.

[0012] Preferably, the chemical composition of the micro-expansive soil is 45%-62% SiO2, 18%-28% Al2O3, 9%-16% Fe2O3, 15%-30% water content, and a natural density of 1.3-1.9 g·cm -3 .

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. The present invention adopts industrial waste residue-based curing agent to realize the recycling of solid waste resources. Compared with cement, when the solidified soil achieves the same strength effect, the CO2 emission is 40%-65% lower. At the same time, palm fiber is an environmentally friendly material and is easy to obtain. The fiber-reinforced industrial waste residue-improved solidified soil has significant environmental and economic benefits.

[0015] 2. The present invention utilizes water glass alkaline agent to stimulate fly ash and steel slag powder, accelerates the formation of hydration products, and improves the strength of expansive soil. At the same time, the two industrial waste slag components have large specific surface areas, and fly ash can absorb free calcium oxide in steel slag powder, solving the problem of poor stability of steel slag powder. The combined blending of the two improves the poor working performance of the single-blended components.

[0016] 3. The addition of plant fiber in the present invention can effectively improve the stress mode of expansive soil. When the fiber is mixed into the soil, a spatial network structure is formed inside the soil. The contact surface between the two produces relative friction, which limits the expansion and micro-deformation of the entire soil and improves the mechanical properties of the soil.

[0017] 4. Different from the effect of ordinary curing agents on improving soil, the present invention adopts fiber-reinforced industrial waste residue-based soil curing method, which can effectively improve the soil's later compression, shear strength and ductility. At the same time, the alkali activation reaction can shorten the curing age. DETAILED DESCRIPTION

[0018] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments.

[0019] Example 1: Preparation of a solidified soil mixture, the soil to be treated has a soil moisture content of 15.8% and a natural density of 1.52 g·cm -3 , the best moisture content is 18.2%, of which SiO2 is 53%, Al2O3 is 21%, and Fe2O3 is 10%. According to weight percentage, 6% fly ash, 4% blast furnace slag, and 2.5% steel slag powder are added to the soil, and the mixture is fully mixed for 30 minutes to obtain a mixture; 3% water glass is added to the mixture, and the mixture is stirred in a mixer for 20 minutes to obtain a mixture, in which the molar ratio of silicon dioxide to sodium oxide is 3.1; palm fiber is chopped into 5mm lengths, and added to the mixture in a weight percentage of 0.3%, and the amount of palm fiber added per unit time is controlled not to exceed 0.01% / min to prevent the palm fiber from agglomerating. After the palm fiber is added, stirring is continued for 30 minutes to form the final solidified soil mixture, and the compaction degree after solidification is 95%, and the solidification age is 7 days.

[0020] Example 2: Preparation of a solidified soil mixture, the soil to be treated has a soil moisture content of 15.8% and a natural density of 1.52 g·cm -3 , the best moisture content is 18.2%, of which SiO2 is 53%, Al2O3 is 21%, and Fe2O3 is 10%. According to weight percentage, 6% fly ash, 4% blast furnace slag, and 2.5% steel slag powder are added to the soil, and the mixture is fully mixed for 30 minutes to obtain a mixture; 3% water glass is added to the mixture, and the mixture is stirred in a mixer for 20 minutes to obtain a mixture, in which the molar ratio of silicon dioxide to sodium oxide is 3.1; palm fiber is chopped into 5mm lengths, and added to the mixture in a weight percentage of 0.3%, and the amount of palm fiber added per unit time is controlled not to exceed 0.01% / min to prevent the palm fiber from agglomerating. After the palm fiber is added, stirring is continued for 30 minutes to form the final solidified soil mixture, and the compaction degree after solidification is 95%, and the solidification age is 28 days.

[0021] Example 3: Preparation of a solidified soil mixture, the soil to be treated has a soil moisture content of 19.2% and a natural density of 1.71 g·cm -3, the best moisture content is 25.6%, of which SiO2 is 71%, Al2O3 is 11%, and Fe2O3 is 5%. According to weight percentage, 9% fly ash, 4% blast furnace slag, and 2% steel slag powder are added to the soil, and the mixture is fully mixed for 30 minutes to obtain a mixture; 3% water glass is added to the mixture, and the mixture is stirred in a mixer for 20 minutes to obtain a stirrer, in which the molar ratio of silicon dioxide to sodium oxide is 3.1; palm fiber is chopped into 10mm lengths, and added to the stirrer in a weight percentage of 0.5%, and the amount of palm fiber added per unit time is controlled not to exceed 0.01% / min to prevent the palm fiber from agglomerating. After the palm fiber is added, stirring is continued for 30 minutes to form the final solidified soil mixture, and the compaction degree after solidification is 95%, and the solidification age is 7 days.

[0022] Example 4: Preparation of a solidified soil mixture, the soil to be treated has a soil moisture content of 19.2% and a natural density of 1.71 g·cm -3 , the best moisture content is 25.6%, of which SiO2 is 71%, Al2O3 is 11%, and Fe2O3 is 5%. According to weight percentage, 9% fly ash, 4% blast furnace slag, and 2% steel slag powder are added to the soil, and the mixture is fully mixed for 30 minutes to obtain a mixture; 3% water glass is added to the mixture, and the mixture is stirred in a mixer for 20 minutes to obtain a mixture, in which the molar ratio of silicon dioxide to sodium oxide is 3.1; palm fiber is chopped into 10mm lengths, and added to the mixture in a weight percentage of 0.5%, and the amount of palm fiber added per unit time is controlled not to exceed 0.01% / min to prevent the palm fiber from agglomerating. After the palm fiber is added, stirring is continued for 30 minutes to form the final solidified soil mixture, and the compaction degree after solidification is 95%, and the solidification age is 28 days.

[0023] Comparative Example 1: Preparation of a solidified soil mixture, in which the soil to be treated has a soil moisture content of 15.8% and a natural density of 1.52 g·cm -3 The optimum moisture content is 18.2%, including 53% SiO2, 21% Al2O3 and 10% Fe2O3. According to the weight percentage, 12.5% ​​cement (PO32.5) is added to the soil to obtain a solidified soil mixture. The compaction degree after solidification is 95% and the curing period is 7 days.

[0024] Comparative Example 2: Preparation of a solidified soil mixture, in which the soil to be treated has a soil moisture content of 19.2% and a natural density of 1.71 g·cm -3The optimum moisture content is 25.6%, including 71% SiO2, 11% Al2O3 and 5% Fe2O3. According to the weight percentage, 15% cement (PO32.5) is added to the soil to obtain a solidified soil mixture. The compaction degree after solidification is 95% and the curing period is 7 days.

[0025] Comparative Example 3: Preparation of a solidified soil mixture, in which the soil to be treated has a soil moisture content of 19.2% and a natural density of 1.71 g·cm -3 The optimum moisture content is 25.6%, including 71% SiO2, 11% Al2O3 and 5% Fe2O3. According to the weight percentage, 15% cement (PO32.5) is added to the soil to obtain a solidified soil mixture. The compaction degree after solidification is 95% and the curing period is 28 days.

[0026] For the above embodiments and comparative examples, test specimens were made in accordance with the Geotechnical Test Method Standard (GB / T50123-2019), and the unconfined compressive strength results were measured as shown in Table 1.

[0027] Table 1 Unconfined compressive strength and shear strength results of various embodiments and comparative examples

[0028]

[0029]

[0030] In summary, the present invention utilizes industrial waste residue (fly ash, steel slag powder, etc. mixed in a certain proportion) to improve the physical and mechanical properties of soft soil through alkali (water glass) stimulation reaction, and at the same time, a certain amount and length of plant fiber (palm fiber) is added into the mixed soil, which can enhance the unconfined compressive strength and splitting tensile strength of the soil.

[0031] The above are only implementation modes of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent schemes made using the contents of the present invention specification, directly or indirectly applied in other related technical fields, are also within the patent protection scope of the present invention.

Claims

1. A fiber-reinforced industrial waste residue-based curing agent, characterized in that: Calculated by weight percentage, it includes the following components: fly ash 5%-12%, blast furnace slag 4%-7%, steel slag powder 2%-5%, water glass 3%-8%, and palm fiber 0.2%-0.6%.

2. The fiber-reinforced industrial waste residue-based curing agent according to claim 1, characterized in that: In the water glass, the molar ratio of silicon dioxide to sodium oxide is 2.5-4.

3. The fiber-reinforced industrial waste residue-based curing agent according to claim 1, characterized in that: The length of the palm fiber is 5-12 mm.

4. A method for preparing a fiber-reinforced industrial waste residue-based curing agent, characterized in that: The steps include: Step 1: Weigh 5%-12% fly ash, 4%-7% blast furnace slag, and 2%-5% steel slag powder, and mix them thoroughly for 30 minutes to obtain a mixture; Step 2: Add 3%-8% of water glass to the mixture, continue stirring for 20 minutes, and obtain a stirrer; in the water glass, the molar ratio of silicon dioxide to sodium oxide is 2.5-4; Step 3: chop the palm fiber into pieces of 5-12 mm in length, add 0.2%-0.6% by weight to the stirred substance, control the amount of palm fiber added per unit time to not exceed 0.01% / min, and continue stirring for 30 minutes after the palm fiber is added to obtain a fiber-reinforced industrial waste residue-based curing agent.

5. Use of the fiber-reinforced industrial waste residue-based curing agent according to any one of claims 1 to 3 or the fiber-reinforced industrial waste residue-based curing agent prepared according to claim 4 in treating slightly expansive soil.

6. The use according to claim 5, characterized in that The chemical composition of the micro-expansive soil is SiO2 45%-62%, Al2O3 18%-28%, Fe2O3 9%-16%, water content 15%-30%, and natural density 1.3-1.9 g·cm -3 .

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