Cement-based grouting material for improving crack resistance of grouted semi-flexible mixture and preparation method of cement-based grouting material

Abstract

The invention relates to the field of cement-based grouting materials, and particularly discloses a cement-based grouting material capable of improving the crack resistance of a grouted semi-flexible mixture and a preparation method of the cement-based grouting material. The invention discloses a cement-based grouting material for improving the crack resistance of a grouted semi-flexible mixture. The cement-based grouting material is prepared from the following raw materials in parts by weight: 50 to 65 parts of polymer modified cement, 12 to 17 parts of silicon dioxide modified recycled tire fiber, 30 to 45 parts of composite aggregate, 5 to 10 parts of gypsum, 5 to 10 parts of fly ash, 0.6 to 0.8 part of a water reducing agent, 0.1 to 0.2 part of a de-foaming agent and 16 to 21 parts of water, the polymer modified cement comprises hydrophilic modified chloroprene rubber and Portland cement in a mass ratio of (1-3): (8-10). The crack resistance of the cement-based grouting material is improved, the interface bonding strength of the cement-based grouting material and a matrix asphalt mixture is improved, and comprehensive utilization of waste tires is realized.

Description

TECHNICAL FIELD

[0001] The application relates to the field of cement-based grouting materials, in particular to a cement-based grouting material for improving the crack resistance of grouting semi-flexible mixture and a preparation method thereof. BACKGROUND

[0002] The grouting semi-flexible pavement is a new type of pavement structure formed by grouting cement-based grouting material into the base asphalt mixture with large pores. The cement-based grouting material is a dry-mixed material composed of cement as a cementitious material, high-strength aggregate, functional admixture and mineral admixture, etc. In the use process, the cement-based grouting material inevitably encounters drying shrinkage and temperature shrinkage, which easily leads to shrinkage cracks in the later period and affects the integrity. In the combination process of the cement-based grouting material and the base asphalt mixture, there is a problem of weak interface bonding, and under the action of long-term load and temperature stress, the semi-flexible pavement structure is damaged in integrity and loses function. In addition, hundreds of millions of tons of waste tires are produced in China every year, and the traditional stacking and landfill methods occupy a large amount of land, pollute the soil and underground water, and seriously affect the ecological environment.

[0003] Therefore, it is urgent to provide an environmentally friendly cement-based grouting material for recycling waste tires, which not only has high crack resistance, but also has high interface bonding strength with the base asphalt mixture. SUMMARY

[0004] In order to improve the crack resistance of the cement-based grouting material, increase the interface bonding strength with the base asphalt mixture, and realize the comprehensive utilization of waste tires, the application provides a cement-based grouting material for improving the crack resistance of grouting semi-flexible mixture and a preparation method thereof.

[0005] In the first aspect, the application provides a cement-based grouting material for improving the crack resistance of grouting semi-flexible mixture, which adopts the following technical scheme: A cement-based grouting material for improving the crack resistance of grouting semi-flexible mixture, comprising the following raw materials by weight: 50-65 parts of polymer modified cement, 12-17 parts of silica modified recycled tire fiber, 30-45 parts of composite aggregate, 5-10 parts of gypsum, 5-10 parts of fly ash, 0.6-0.8 parts of water reducing agent, 0.1-0.2 parts of defoaming agent, and 16-21 parts of water; the polymer modified cement comprises hydrophilic modified neoprene and portland cement with a mass ratio of 1-3:8-10.

[0006] By adopting the technical scheme, the hydrophilic modified chloroprene rubber modified Portland cement is adopted, which increases the toughness of the cement, and a large number of hydroxyl and carboxyl groups in the hydrophilic modified chloroprene rubber can form a bridge with metal ions in the cement to improve the compactness of the cement-based grouting material and increase the bonding performance with the base asphalt mixture; the recycled tire fiber is modified by the silicon dioxide, the silicon dioxide reacts with the cement hydration product calcium hydroxide to generate calcium silicate hydrate gel, which reduces the porosity, improves the cement compactness and crack resistance, and the fiber structure forms a uniform random support system in the cement, which can prevent the microcracks from expanding into fine cracks, and further enhances the crack resistance of the cement; the composite aggregate is composed of recycled aggregate and superabsorbent resin, the recycled aggregate is dispersed in the cement-based grouting material as a strength support, and the superabsorbent resin can release water molecules as a water storage reservoir, promote the hydration reaction of the interface layer cement between the recycled aggregate and the cement, increase the tightness and strength of the interface layer structure, and improve the homogeneity and crack resistance of the cement-based grouting material.

[0007] Optionally, the preparation method of the hydrophilic modified chloroprene rubber comprises the following steps: The chloroprene rubber is added into toluene, stirred and dissolved, methyl methacrylate, hydroxyethyl methacrylate, glycidyl methacrylate and acrylic acid are added, heated to 80-90℃, benzoyl peroxide is added and reacted for 1-3h, cooled to room temperature, rosin glyceride is added, stirred, rotary evaporated, and ground to obtain the hydrophilic modified chloroprene rubber.

[0008] By adopting the technical scheme, the hydrophilic modified chloroprene rubber is uniformly dispersed in the cement slurry during the cement hydration process, and as the water is consumed and evaporated, the hydrophilic modified chloroprene rubber will flocculate and tightly accumulate to form a continuous polymer film, forming an organic-inorganic interpenetrating network structure, which increases the crack resistance of the cement; the surface of the hydrophilic modified chloroprene rubber contains a large number of hydroxyl and carboxyl groups, which react with metal ions during the hydration process of the cement to form a bridge, thereby improving the compactness of the cement-based grouting material and increasing the bonding performance with the base asphalt mixture, thereby increasing the crack resistance of the cement composite.

[0009] Optionally, the raw material of the silicon dioxide modified recycled tire fiber comprises recycled tire fiber and silicon dioxide in a mass ratio of 1-3:5-7.

[0010] Optionally, the preparation method of the silicon dioxide modified recycled tire fiber comprises the following steps: The tire is crushed, ground, and sieved to obtain the recycled tire fiber; The silane coupling agent is added to deionized water, the pH is adjusted to 5-6, sodium dodecyl benzene sulfonate and silicon dioxide are added, ultrasonic is performed, the recycled tire fiber is added, stirred uniformly, and dried to obtain the silicon dioxide modified recycled tire fiber.

[0011] Optionally, the length of the recycled tire fiber is 5-10 mm.

[0012] By adopting the technical scheme, after the tire is crushed and ground, steel fibers and polymer fibers are obtained, silica is adsorbed on the surface of the fibers through van der Waals force and electrostatic attraction, sodium dodecyl benzene sulfonate is used as a dispersant to prevent silica from agglomerating and promote the uniform distribution of silica on the surface of the fibers; after the silica is coupled by a silane coupling agent, the surface changes from hydrophilic to hydrophobic, which has high interfacial bonding with the organic long chain of hydrophilic modified chlorobutyl rubber, increases the bonding strength of the silica modified recycled tire fiber and the polymer modified cement, and the fibers can reduce the number of crack sources caused by the shrinkage of cement; in addition, the fibers form a uniform random support system inside the mortar, which can prevent crack propagation and enhance the crack resistance of cement during the development of microcracks to fine cracks; the silica chemically reacts with the cement hydration product calcium hydroxide at room temperature to generate calcium silicate hydrate (C-S-H) gel, which reduces the porosity and improves the density and crack resistance of the cement-based grouting material.

[0013] Optionally, the preparation method of the composite aggregate comprises the following steps: The waste concrete is impurity-removed, crushed, sieved, and recycled aggregate is prepared; The recycled aggregate is mixed with the superabsorbent resin according to a mass ratio of 3-6:7-9 to prepare the composite aggregate.

[0014] By adopting the technical scheme, after the waste concrete is crushed and sieved, a mixture of sand, metal reinforcement and light materials (wood, plastic) is obtained, the metal reinforcement and light materials are removed by magnetic separation and water separation, and the recycled aggregate (sand) is obtained as a skeleton to play a supporting role; the superabsorbent resin has a three-dimensional network structure, a large number of strong water-absorbing groups such as carboxyl and hydroxyl groups on the surface, can quickly absorb and hold a large amount of water, and swell into hydrogel particles, which are uniformly distributed in the cement paste; as the cement hydration reaction proceeds, the humidity inside the cement-based grouting material decreases, producing shrinkage stress, the superabsorbent resin slowly releases water, making the hydration reaction more complete and complete, reducing the risk of early cracking of the cement-based grouting material, and further improving its durability; the recycled aggregate, polymer cement and asphalt mixture form a weak interfacial layer, which is easy to produce microcracks, leading to cracking of the mixture, while the superabsorbent resin releases water molecules near the interfacial layer, promoting the hydration reaction of the polymer cement in this area, increasing the tightness of the interfacial layer structure, and improving the homogeneity and crack resistance of the cement-based grouting material.

[0015] Optionally, the preparation method of the superabsorbent resin comprises the following steps: (1) crushing, grinding and sieving the waste ceramic to prepare recycled ceramic powder; (2) neutralizing acrylic acid with NaOH solution in an ice water bath, adding recycled porcelain powder and N,N-methylene bisacrylamide, stirring to prepare a mixed solution; (3) under inert atmosphere, adding ammonium persulfate dropwise to the mixed solution, heating and stirring for 2-4h, washing with ethanol, drying, crushing, sieving to prepare a superabsorbent resin.

[0016] By adopting the technical scheme, the recycled porcelain powder is prepared by crushing waste ceramic, realizing resource utilization, ammonium persulfate is decomposed into anion free radicals under heating conditions, initiating polymerization of acrylic acid monomers to generate polyacrylic acid chain free radicals, with the reaction proceeding, the concentration of chain free radicals and the concentration of carboxyl groups on the polyacrylic acid chain continuously increase, Si-OH on the surface of the recycled porcelain powder meets the carboxyl groups on the polyacrylic acid chain free radicals, esterification reaction occurs, and the polyacrylic acid chain free radicals undergo chain termination reaction due to strong interaction, under the action of N,N-methylene bisacrylamide, a three-dimensional crosslinked resin network is formed, the strength and stability of the cement-based grouting material are improved, and the superabsorbent resin has extremely strong water absorption and water retention performance; the recycled porcelain powder has a porous structure with tiny pores and channels, when water molecules contact the tiny pores, the surface tension of water will promote the water molecules to move into the pores and channels, realizing deep water storage, when the cement dries and cracks, the water molecules move out of the channels, wetting the superabsorbent resin, and then preventing the cement from cracking.

[0017] Optionally, the water reducing agent is a polycarboxylic acid type high-performance water reducing agent.

[0018] Optionally, the defoaming agent is an organic silicon type powder defoaming agent.

[0019] In a second aspect, the application provides a preparation method of a cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, adopting the following technical scheme: A preparation method of a cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, comprising the following steps: adding silica modified recycled tire fibers and a water reducing agent into water, mixing uniformly to prepare a mixed solution; mixing a polymer modified cement, a composite aggregate, gypsum, fly ash and a defoaming agent uniformly to prepare a mixed powder; slowly pouring the mixed solution into the mixed powder under stirring, mixing uniformly to prepare a cement-based grouting material.

[0020] In summary, the application has the following beneficial effects: 1、The application preferably uses polymer modified cement as a gel material to improve the compactness of the cement-based grouting material and increase the bonding performance with the base asphalt mixture; the recycled tire fiber is modified by adding silicon dioxide, which forms a uniform random support system inside the mortar to prevent the expansion of the cement-based cracks, and the composite aggregate can slowly release moisture to make the hydration reaction more complete and reduce the risk of early cracking of the cement-based grouting material, thereby further improving the durability thereof; the polymer modified cement, the silicon dioxide modified recycled tire fiber and the composite aggregate are combined to improve the crack resistance of the cement-based grouting material and the interfacial bonding strength with the base asphalt mixture, thereby achieving comprehensive utilization of waste tires.

[0021] 2、The application uses hydrophilic modified neoprene rubber to modify cement, the hydrophilic modified neoprene rubber contains a large number of hydroxyl and carboxyl groups, can react with metal ions in cement to produce a bridge bond, and can form an organic-inorganic interpenetrating network structure in cement, thereby further increasing the crack resistance of the cement composite.

[0022] 3、The application uses high water absorption resin with recycled porcelain powder as a core material as a water storage reservoir for cement, which slowly releases moisture to promote the cement hydration reaction and increase the cement hydration reaction between the interface layer of the recycled aggregate, polymer cement and asphalt mixture, thereby improving the homogeneity and crack resistance of the cement-based grouting material. DETAILED DESCRIPTION

[0023] The following examples further illustrate the application.

[0024] Preparation example of polymer modified cement The neoprene rubber was purchased from Bayer Company in Germany, and the model number was B210; the methyl methacrylate was purchased from Shanghai Huayi Company, and the CAS number was 80-62-6; the glycidyl methacrylate was purchased from Shanghai Yuan Ye Biological Technology Co., Ltd., and the number was S60373; the rosin glyceride was purchased from Zhangjiagang Sunshine Chemical Co., Ltd., and the model number was 140; the portland cement was purchased from Jiuli Building Material Co., Ltd., and the model number was PO42.5.

[0025] Preparation example 1 (1) 90g of neoprene rubber was added to 220g of toluene, stirred and dissolved, 45g of methyl methacrylate, 2g of hydroxyethyl methacrylate, 3g of glycidyl methacrylate and 12g of acrylic acid were added, heated to 85℃, 0.8g of benzoyl peroxide with a concentration of 0.03mol / L was added and reacted for 2h, cooled to room temperature, 45g of rosin glyceride was added, stirred, rotary evaporated at 60℃, and ground to obtain hydrophilic modified neoprene rubber; (2) 10g of portland cement and 80g of hydrophilic modified neoprene rubber were mixed uniformly to obtain polymer modified cement.

[0026] Preparation example 2 (1) 90 g of chlorobutyl rubber was added to 220 g of toluene, stirred and dissolved, 45 g of methyl methacrylate, 2 g of hydroxyethyl methacrylate, 3 g of glycidyl methacrylate and 12 g of acrylic acid were added, heated to 85°C, 0.8 g of benzoyl peroxide with a concentration of 0.03 mol / L was added and reacted for 2 h, cooled to room temperature, 45 g of rosin glyceride was added, stirred, rotary evaporated at 60°C, and ground to obtain hydrophilic modified chlorobutyl rubber; (2) 30 g of silicate cement and 100 g of hydrophilic modified chlorobutyl rubber were mixed uniformly to obtain polymer modified cement.

[0027] Preparation Example 3 The difference from Preparation Example 1 is that no acrylic acid is added in step (1).

[0028] Preparation Example 4 The difference from Preparation Example 1 is that the hydrophilic modified chlorobutyl rubber is replaced by an equal amount of chlorobutyl rubber.

[0029] Preparation Example of Silica Modified Recycled Tire Fiber The silane coupling agent is purchased from Nanjing Liansihuang Chemical Co., Ltd., and the model number is KH550; the particle size of the silica is 20 nm, and it is purchased from Shanghai Xiaohua Nanometer Technology Co., Ltd., and the product number is XH-SiO2-15.

[0030] Preparation Example 1 (1) The waste tire was crushed, ground, and sieved to obtain recycled tire fibers with a length of 6 mm; (2) 0.1 g of silane coupling agent was added to 15 g of deionized water, the pH was adjusted to 5 with dilute hydrochloric acid, 1 g of sodium dodecyl benzene sulfonate and 1 g of silica were added, ultrasonic treatment was performed for 30 min, 7 g of recycled tire fibers were added, stirred uniformly, and dried at 60°C for 24 h to obtain silica modified recycled tire fibers.

[0031] Preparation Example 2 (1) The waste tire was crushed, ground, and sieved to obtain recycled tire fibers with a length of 9 mm; (2) 0.1 g of silane coupling agent was added to 15 g of deionized water, the pH was adjusted to 5 with dilute hydrochloric acid, 1 g of sodium dodecyl benzene sulfonate and 1 g of silica were added, ultrasonic treatment was performed for 30 min, 7 g of recycled tire fibers were added, stirred uniformly, and dried at 60°C for 24 h to obtain silica modified recycled tire fibers.

[0032] Preparation Example 3 The difference from Preparation Example 1 is that the recycled tire fibers are replaced by an equal amount of recycled tire powder, and the preparation method of the recycled tire powder is as follows: the recycled tire fibers are crushed, ground, and sieved through a 0.5 mm sieve.

[0033] Preparation Example 4 The difference from Preparation Example 1 is that the recycled tire fiber with a length of 6 mm is replaced by an equal amount of recycled tire fiber with a length of 20 mm.

[0034] Preparation Example of Composite Aggregate The talc powder is purchased from Liaoning Aihai Talc Co., Ltd., and the model is AH51210L.

[0035] Preparation Example 1 (1) The waste concrete is preliminarily crushed, the iron filings are removed by magnet adsorption, water is added, stirred, and the light materials such as wood and plastic are removed, dried at 80°C for 24 h, crushed again, sieved through a 1.5 mm screen, and the recycled aggregate is prepared; (2) The waste ceramic is crushed, ground, and sieved through a 0.5 mm screen to prepare the recycled ceramic powder; (3) 270 g of NaOH solution with a concentration of 8 mol / L is neutralized with 150 g of acrylic acid in an ice water bath, 10 g of recycled ceramic powder and 0.075 g of N,N-methylene bisacrylamide are added, stirred, and the mixed solution is prepared; (4) Under a nitrogen atmosphere, 22.5 g of ammonium persulfate is added dropwise to the mixed solution, stirred at 65°C for 4 h, washed with ethanol, dried at 60°C for 24 h, crushed, and sieved through a 0.87 mm screen to prepare the superabsorbent resin; (5) 30 g of recycled aggregate is mixed uniformly with 90 g of superabsorbent resin to prepare the composite aggregate.

[0036] Preparation Example 2 (1) The waste concrete is preliminarily crushed, the iron filings are removed by magnet adsorption, water is added, stirred, and the light materials such as wood and plastic are removed, dried at 80°C for 24 h, crushed again, sieved through a 1.5 mm screen, and the recycled aggregate is prepared; (2) The waste ceramic is crushed, ground, and sieved through a 0.5 mm screen to prepare the recycled ceramic powder; (3) 270 g of NaOH solution with a concentration of 8 mol / L is neutralized with 150 g of acrylic acid in an ice water bath, 10 g of recycled ceramic powder and 0.075 g of N,N-methylene bisacrylamide are added, stirred, and the mixed solution is prepared; (4) Under a nitrogen atmosphere, 22.5 g of ammonium persulfate is added dropwise to the mixed solution, stirred at 65°C for 4 h, washed with ethanol, dried at 60°C for 24 h, crushed, and sieved through a 0.87 mm screen to prepare the superabsorbent resin; (5) 60 g of recycled aggregate is mixed uniformly with 70 g of superabsorbent resin to prepare the composite aggregate.

[0037] Preparation Example 3 The difference from Preparation Example 1 is that in step (3), no recycled ceramic powder is added.

[0038] Preparation Example 4 The difference from Preparation Example 1 is that in step (3), the recycled porcelain powder is replaced by an equal amount of talc powder.

[0039] Preparation Example 5 The difference from Preparation Example 1 is that no super absorbent resin is added, and the specific preparation method is as follows: the waste concrete is preliminarily crushed, the iron filings are removed by magnet adsorption, water is added, stirred, and the light materials such as wood and plastic are removed, dried at 80°C for 24h, and then crushed again and sieved through a 1.5mm screen. Example

[0040] In the following examples, the gypsum was purchased from Tianmen Hengchang Chemical Co., Ltd., with the product number HC3462; the fly ash was purchased from Wuhan Jiyesheng Chemical Co., Ltd., with the product number A01085; the silicone solid powder defoaming agent was purchased from Hefei Yuguan New Materials Co., Ltd., with the model number DE-1185; the polycarboxylic acid water reducing agent was purchased from Shanjiang Xianrui Building Material Co., Ltd., with the model number 101; the river sand had a particle size of 1-2mm and was purchased from Nanjing Liuhu District Gaosheng Yuhua Stone Factory; the quartz sand had a particle size of 0.5-1mm and was purchased from Henan Fange Environmental Protection Material Co., Ltd.

[0041] Example 1: A cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, the raw material usage is shown in Table 1, the polymer modified cement is prepared by the method in the polymer modified cement preparation example 1; the silica modified recycled tire fiber is prepared by the method in the silica modified recycled tire fiber preparation example 1; the composite aggregate is composed of 25% river sand and 75% quartz sand; the water reducing agent is a polycarboxylic acid water reducing agent; and the defoaming agent is a silicone solid powder defoaming agent.

[0042] The above-mentioned preparation method of the cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture includes the following steps: adding the silica modified recycled tire fiber and the water reducing agent into water, mixing uniformly to obtain a mixed liquid; adding the polymer modified cement, the composite aggregate, the gypsum, the fly ash and the defoaming agent into a concrete mixer, mixing uniformly to obtain a mixed powder; slowly pouring the mixed liquid into the mixed powder in the mixer, mixing uniformly to obtain the cement-based grouting material.

[0043] Table 1 Raw material usage of HIPS cement-based grouting material in Examples 1-4 Example 2: A cement-based grout for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the raw material usage is as shown in Table 1, the polymer-modified cement is prepared by the method in Polymer-modified cement preparation example 2; the silica-modified recycled tire fiber is prepared by the method in Silica-modified recycled tire fiber preparation example 2; the composite aggregate is composed of 25% river sand and 75% quartz sand; the water reducing agent is a polycarboxylic acid water reducing agent; and the defoaming agent is an organic silicon solid powder defoaming agent.

[0044] Example 3: A cement-based grout for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the raw material usage is as shown in Table 1, the polymer-modified cement is prepared by the method in Polymer-modified cement preparation example 1; the silica-modified recycled tire fiber is prepared by the method in Silica-modified recycled tire fiber preparation example 2; the composite aggregate is composed of 25% river sand and 75% quartz sand; the water reducing agent is a polycarboxylic acid water reducing agent; and the defoaming agent is an organic silicon solid powder defoaming agent.

[0045] Example 4: A cement-based grout for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the raw material usage is as shown in Table 1, the polymer-modified cement is prepared by the method in Polymer-modified cement preparation example 2; the silica-modified recycled tire fiber is prepared by the method in Silica-modified recycled tire fiber preparation example 1; the composite aggregate is composed of 25% river sand and 75% quartz sand; the water reducing agent is a polycarboxylic acid water reducing agent; and the defoaming agent is an organic silicon solid powder defoaming agent.

[0046] Example 5: A cement-based grout for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the silica-modified recycled tire fiber is prepared by the method in Silica-modified recycled tire fiber preparation example 3.

[0047] Example 6: A cement-based grout for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the silica-modified recycled tire fiber is prepared by the method in Silica-modified recycled tire fiber preparation example 4.

[0048] Example 7: A cement-based grout for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the composite aggregate is prepared by the method in Composite aggregate preparation example 1.

[0049] Example 8: A cement-based grout for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the composite aggregate is prepared by the method in Composite aggregate preparation example 2.

[0050] Example 9: A cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 7 in that the composite aggregate is prepared by the method in Composite Aggregate Preparation Example 3.

[0051] Example 10: A cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 7 in that the composite aggregate is prepared by the method in Composite Aggregate Preparation Example 4.

[0052] Example 11: A cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 7 in that the composite aggregate is prepared by the method in Composite Aggregate Preparation Example 5.

[0053] Comparative Example Comparative Example 1: A cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the polymer-modified cement is prepared by the method in Polymer-Modified Cement Preparation Example 3.

[0054] Comparative Example 2: A cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the polymer-modified cement is prepared by the method in Polymer-Modified Cement Preparation Example 4.

[0055] Comparative Example 3: A cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the polymer-modified cement is replaced with an equal amount of Portland cement.

[0056] Comparative Example 4: A cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that the silica-modified recycled tire fiber is replaced with an equal amount of recycled tire fiber, and the recycled tire fiber is prepared by: crushing, grinding, and sieving waste tires to obtain recycled tire fibers with a length of 6 mm.

[0057] Comparative Example 5: A cement-based grouting material for improving the crack resistance of a poured semi-flexible mixture, which differs from Example 1 in that no silica-modified recycled tire fiber is added.

[0058] Performance Test The antibacterial HIPS plastic for automotive interiors was prepared according to the methods in the examples and comparative examples, and the performance was tested according to the following methods, and the test results are recorded in Table 2.

[0059] 1. Fluidity: Initial fluidity and 30 min fluidity were tested according to GB / T 50448-2008 "Application Technical Specification for Cement-Based Grouting Materials".

[0060] 2) Compressive strength and flexural strength: The compressive strength and flexural strength were tested according to GB / T 17671-1999 "Cement-dust strength test method", and the pouring molding was used instead of vibration molding.

[0061] Table 2 Test results of flowability and crack resistance of cement-based grouting materials prepared by examples and comparative examples As can be seen from Table 2, the cement-based grouting materials prepared by Examples 1-4 have good flowability, compressive strength and flexural strength, the initial flowability is 11.1-12.1 s, the 30 min flowability is 15.3-16.5 s, the 1 d compressive strength is 65-71 MPa, the 7 d compressive strength is 79-84 MPa, the 28 d compressive strength is 99-106 MPa, the 1 d flexural strength is 6.04-6.12 MPa, the 7 d flexural strength is 10.53-11.45 MPa, and the 28 d flexural strength is 15.21-15.34 MPa, indicating that the prepared cement-based grouting material has high flowability and high crack resistance, and the combination of polymer modified cement, silica modified recycled tire fiber and composite aggregate can enhance the crack resistance of the cement-based grouting material.

[0062] In the preparation process of the silica modified recycled tire fiber of Example 5, the recycled tire fiber is replaced by an equal amount of recycled tire powder. As can be seen from Table 2, compared with Example 1, the compressive strength and flexural strength of the cement-based grouting material prepared by Example 5 are decreased, indicating that the addition of recycled tire fiber helps to improve the crack resistance of the cement-based grouting material.

[0063] In the preparation process of the silica modified recycled tire fiber of Example 6, the recycled tire fiber with a length of 6 mm is replaced by an equal amount of recycled tire fiber with a length of 20 mm. As can be seen from Table 2, compared with Example 1, the flowability of the cement-based grouting material prepared by Example 6 is improved, and the compressive strength and flexural strength are decreased, indicating that the addition of 6 mm recycled tire fiber helps to improve the flowability and crack resistance of the cement-based grouting material.

[0064] In the preparation process of the composite aggregate of Example 7 and Example 8, the recycled aggregate is modified by superabsorbent resin. As can be seen from Table 2, compared with Example 1, the 1 d compressive strength and 1 d flexural strength of the cement-based grouting material prepared by Example 7 and Example 8 are slightly reduced, and the 7 d, 28 d compressive strength and flexural strength are significantly reduced, indicating that the modification of recycled aggregate by superabsorbent resin can increase the interfacial bonding strength between the aggregate and the polymer modified cement, and help to improve the crack resistance of the cement-based grouting material.

[0065] Example 9 does not add recycled porcelain powder in the preparation process of composite aggregate, and Example 10 replaces the recycled porcelain powder with talc in the preparation process of composite aggregate. As shown in Table 2, compared with Example 7, the compressive strength and the flexural strength of the cement-based grouting material prepared in Example 9 and Example 10 are significantly reduced, indicating that the addition of recycled porcelain powder helps to improve the crack resistance of the cement-based grouting material.

[0066] Example 11 does not add superabsorbent resin in the preparation process of composite aggregate. As shown in Table 2, compared with Example 7, the 1d compressive strength and the flexural strength of the cement-based grouting material prepared in Example 11 are slightly improved, and the 7d and 28d compressive strength and the flexural strength are significantly reduced, indicating that the addition of superabsorbent resin can improve the surface hydration degree of recycled aggregate and help to improve the crack resistance of the cement-based grouting material.

[0067] Comparative Example 1 does not add acrylic acid in the preparation process of polymer modified cement. As shown in Table 2, compared with Example 1, the compressive strength and the flexural strength of the cement-based grouting material prepared in Comparative Example 1 are significantly reduced, indicating that the addition of acrylic acid helps to improve the crack resistance of the cement-based grouting material.

[0068] Comparative Example 2 replaces the hydrophilic modified chloroprene rubber with chloroprene rubber in the preparation process of polymer modified cement. As shown in Table 2, compared with Example 1, the compressive strength and the flexural strength of the cement-based grouting material prepared in Comparative Example 2 are significantly reduced, indicating that the addition of hydrophilic modified chloroprene rubber helps to improve the crack resistance of the cement-based grouting material.

[0069] Comparative Example 3 replaces the polymer modified cement with Portland cement in the preparation process of the cement-based grouting material for improving the crack resistance of the grouting type semi-flexible mixture. As shown in Table 2, compared with Example 1, the compressive strength and the flexural strength of the cement-based grouting material prepared in Comparative Example 3 are significantly reduced, indicating that the use of polymer to modify Portland cement helps to improve the crack resistance of the cement-based grouting material.

[0070] Comparative Example 4 replaces the silicon dioxide modified recycled tire fiber with recycled tire fiber in the preparation process of the cement-based grouting material for improving the crack resistance of the grouting type semi-flexible mixture. As shown in Table 2, compared with Example 1, the compressive strength and the flexural strength of the cement-based grouting material prepared in Comparative Example 4 are significantly reduced, indicating that the use of silicon dioxide to modify the recycled tire fiber helps to improve the crack resistance of the cement-based grouting material.

[0071] In the preparation process of the cement-based grouting material for improving the crack resistance of the poured semi-flexible mixture, no silica modified recycled tire fiber is added in Comparative Example 5. As can be seen from Table 2, the compressive strength and the flexural strength of the cement-based grouting material prepared in Comparative Example 5 are significantly reduced compared to Example 1, indicating that the addition of silica modified recycled tire fiber helps to improve the crack resistance of the cement-based grouting material.

[0072] The specific embodiments are only an explanation of the present application, which is not a limitation of the present application. Those skilled in the art can make modifications to the embodiments according to the needs after reading the specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A cement-based grouting material for improving the crack resistance of injectable semi-flexible mixtures, characterized in that, The polymer modified cement includes 50-65 parts by weight of polymer modified cement, 12-17 parts by weight of silica modified recycled tire fiber, 30-45 parts by weight of composite aggregate, 5-10 parts by weight of gypsum, 5-10 parts by weight of fly ash, 0.6-0.8 parts by weight of water reducing agent, 0.1-0.2 parts by weight of defoaming agent, and 16-21 parts by weight of water; the polymer modified cement includes 1-3:8-10 mass ratio of hydrophilic modified chloroprene rubber and Portland cement.

2. The cement-based grout of claim 1, wherein the cement-based grout is a cement-based grout for improving crack resistance of a semi-flexible mixture, and the semi-flexible mixture is a mixture of a cement-based grout and a semi-flexible material. The preparation method of the hydrophilic modified chloroprene rubber includes the following steps: The chloroprene rubber is added into toluene, stirred and dissolved, methyl methacrylate, hydroxyethyl methacrylate, glycidyl methacrylate and acrylic acid are added, heated to 80-90 DEG C, benzoyl peroxide is added and reacted for 1-3 hours, cooled to room temperature, and rosin glyceride is added, stirred, rotary evaporated, and ground to obtain the hydrophilic modified chloroprene rubber.

3. The cement-based grout of claim 1, wherein the cement-based grout is a cement-based grout for improving crack resistance of a semi-flexible mixture, and the semi-flexible mixture is a mixture of a cement-based material and a filler. The raw material of the silica modified recycled tire fiber includes 1-3:5-7 mass ratio of recycled tire fiber and silica.

4. The cement-based grout of claim 3, wherein the cement-based grout is a cement-based grout for improving crack resistance of a semi-flexible mixture, and the semi-flexible mixture is a mixture of a cement-based grout and a filler. The preparation method of the silica modified recycled tire fiber includes the following steps: The tire is crushed, ground, and sieved to obtain the recycled tire fiber; The silane coupling agent is added into deionized water, the pH is adjusted to 5-6, sodium dodecyl benzene sulfonate and silica are added, ultrasonic is performed, the recycled tire fiber is added, stirred uniformly, and dried to obtain the silica modified recycled tire fiber.

5. The cement-based grout of claim 4, wherein the cement-based grout is a cement-based grout for improving crack resistance of a semi-flexible mixture, and the semi-flexible mixture is a mixture of a cement-based grout and a semi-flexible material. The length of the recycled tire fiber is 5-10 mm.

6. The cement-based grout of claim 1, wherein the cement-based grout is a cement-based grout for improving crack resistance of a semi-flexible mixture. The preparation method of the composite aggregate includes the following steps: The waste concrete is impurity-removed, crushed, and sieved to obtain the recycled aggregate; The recycled aggregate and the superabsorbent resin are mixed according to a mass ratio of 3-6:7-9 to obtain the composite aggregate.

7. The cement-based grout of claim 6, wherein the cement-based grout is a cement-based grout for improving crack resistance of a semi-flexible mixture. The preparation method of the superabsorbent resin includes the following steps: (1) the waste ceramic is crushed, ground, and sieved to obtain the recycled ceramic powder; (2) the NaOH solution is neutralized with acrylic acid in an ice water bath, the recycled ceramic powder and N,N-methylene bisacrylamide are added, and stirred to obtain a mixed solution; (3) under inert atmosphere, ammonium persulfate is added dropwise into the mixed solution, heated and stirred for 2-4 hours, washed with ethanol, dried, crushed, and sieved to obtain the superabsorbent resin.

8. The cement-based grout of claim 1, wherein the cement-based grout is a cement-based grout for improving crack resistance of a semi-flexible mixture. The water reducing agent is a polycarboxylic acid type high performance water reducing agent.

9. The cement-based grout of claim 1, wherein the cement-based grout is a cement-based grout for improving crack resistance of a semi-flexible mixture, and the semi-flexible mixture is a mixture of a cement-based material and a filler. The defoaming agent is an organic silicon type powder defoaming agent.

10. The method of preparing a cement-based grout for improving the crack resistance of a poured semi-flexible mixture according to any one of claims 1 to 9, characterized in that, The method includes the following steps: The silica modified recycled tire fiber and the water reducing agent are added into water and mixed uniformly to obtain a mixed solution; the polymer modified cement, the composite aggregate, the gypsum, the fly ash, and the defoaming agent are mixed uniformly to obtain a mixed powder; and the mixed solution is slowly poured into the mixed powder in stirring to mix uniformly and obtain the cement-based grouting material.

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