A grouting material for rubble masonry reinforcement

Abstract

The application discloses a grouting material for rubble masonry reinforcement, which comprises the following components in mass: cement 60-70 parts, expanding agent 8-12 parts, fly ash 10-20 parts, silica ash 5-10 parts, silicate 1-5 parts, superplasticizer 1-3 parts, water-based epoxy modified acrylic resin 2-8 parts, viscosity modifier 0.02-0.2 parts, floating beads 4-8 parts and defoaming agent 0.3-0.8 parts. The grouting material has the characteristics of strong adhesion, good impermeability, slight expansion, good fluidity and long-term durability, is suitable for rubble masonry reinforcement engineering, and prolongs the service life of the rubble masonry.

Description

TECHNICAL FIELD

[0001] The present application relates to a cement-based material, in particular to a grouting material for rubble masonry reinforcement, and belongs to the technical field of building materials. BACKGROUND

[0002] With the rapid development of human society and the increasing progress of science and technology, people pay more and more attention to the quality and long-term service life of construction projects. Due to scientific and technological reasons, a large number of multi-story masonry structure projects were built in China before the 1990s. Although some of them have been gradually demolished with the development of construction, many of them are still in use. If they are demolished and rebuilt, it will have an adverse impact on people's life and production, so it is necessary to use reinforcement methods to extend their service life as much as possible. Rubble masonry is often used as the foundation of a house, steep slope protection, and a single-story house wall. Due to the influence of construction quality differences and other factors, the compressive, shear, tensile and bending strengths of masonry structures are relatively low, and the overall performance of the structure is poor, resulting in insufficient bearing capacity of the masonry and reduced stability. In order to ensure the safety of masonry structures, it is necessary to reinforce the masonry structure.

[0003] At present, the reinforcement technology for masonry in China includes steel mesh cement mortar outer layer reinforcement method, reinforced concrete outer layer reinforcement method, increase structural column reinforcement method and add buttress column reinforcement method. The above construction methods are relatively complex, the cement mortar or concrete materials used for reinforcement cannot work together with the existing masonry structure, and the stress performance of the reinforced masonry is not significantly improved. Cracks may occur in masonry engineering due to cement drying, thermal expansion and cold contraction. SUMMARY

[0004] In view of the defects of the existing rubble masonry, such as low compressive, shear and tensile strength, weak adhesion between the reinforced cement-based material and the existing masonry structure, and inability to work together, the present application aims to provide a grouting material for rubble masonry reinforcement, which has the characteristics of strong adhesion, good impermeability, micro-expansion, good flowability and long-term durability, and is suitable for rubble masonry reinforcement engineering and prolongs the service life of rubble masonry.

[0005] In order to achieve the above technical purpose, the present application adopts the following technical scheme:

[0006] A grouting material for rubble masonry reinforcement, comprising the following components by mass:

[0007]

[0008] As a preferred scheme, the cement is ordinary portland cement, and the strength grade is 52.5 or 42.5, and further preferably 52.5.

[0009] As a preferred scheme, the expansive agent is calcium sulphoaluminate expansive agent. Calcium sulphoaluminate produces certain limited expansion through its own chemical reaction or reaction with other ingredients in the cement stone, which reduces shrinkage, and the generated ettringite crystals can fill and block capillary holes, thereby improving the mechanical interlocking force with the pores of the masonry, and improving the bonding performance as a whole.

[0010] As a preferred scheme, the fly ash is grade I or grade II power plant fly ash.

[0011] As a preferred scheme, the silica fume particle size is 0.2-0.5 μm, and further preferably 0.3-0.4 μm. The silica fume greatly reduces the pore size in the hydrated slurry, improves the pore size distribution, and the filling effect on the pores of the cement particles can improve the impermeability of the cement slurry. At the same time, the silica fume can reduce the early hydration heat of the cement slurry, and ensure the late strength of the cement slurry.

[0012] As a preferred scheme, the silicate is at least one of sodium silicate, lithium silicate and potassium silicate, and further preferably potassium silicate.

[0013] As a preferred scheme, the superplasticizer is at least one of melamine high-efficiency water reducing agent and polycarboxylic acid high-performance water reducing agent, which can be purchased from Sika Company.

[0014] The water-based epoxy modified acrylic resin of the present application can be prepared by using existing conventional processes, such as polymerization of acrylic acid, hydroxyethyl acrylate, butyl acrylate, methyl methacrylate, styrene, epoxy resin, etc., or can be directly purchased, such as ZTC-018 water-dispersible epoxy modified acrylic resin from Hunan Zhi-to Environmental Protection Technology Co., Ltd. The polymer can fill the pores and microcracks in the cement and concrete, can enhance the compactness thereof, and can enhance the adhesive force of the cement stone, and through water-based epoxy modification, the polymer has the advantages of high strength, corrosion resistance, strong adhesion, and water resistance of the epoxy resin.

[0015] As a preferred scheme, the viscosity modifier is a complex of sarcosine and L-galactose. Further preferably, the mass percentage of sarcosine to L-galactose is 30-60%: 40-70%. The complex viscosity modifier of sarcosine and L-galactose can enhance the plasticity, anti-settling force and anti-segregation of the cement slurry, so that the cement slurry has good fluidity under pressure and good thixotropy under no pressure.

[0016] As a preferred scheme, the size of the floating bead is 120-200 mesh. The floating bead has a ball bearing lubrication effect, which significantly reduces the shear stress of the cement slurry, reduces the plastic viscosity, and makes the cement slurry have excellent fluidity and good permeability, and is convenient to construct.

[0017] As a preferred solution, the defoaming agent is an organosilicon defoaming agent.

[0018] The grouting material for rubble masonry reinforcement of the present application can fill the pores and micro-cracks in cement and concrete by polymer, enhance the density, improve the impermeability of cement paste, and enhance the adhesive force of cement stone, and is modified by water-based epoxy, so that the polymer has the advantages of high strength, corrosion resistance, strong adhesion, and water resistance of epoxy resin; the expansion agent produces certain limited expansion through its chemical reaction or reaction with other components in the cement stone, which not only reduces shrinkage, but also generates ettringite crystals that can fill and block capillary holes, thereby improving the mechanical interlocking force with the masonry pores and the overall bonding performance; the filling effect of silica fume on the pores of cement particles can improve the impermeability of the grouting material; the high-efficiency water-reducing mechanism of the superplasticizer and the ball bearing lubrication provided by the floating beads significantly reduce the shear stress of the cement paste, reduce the plastic viscosity, and make the cement paste have excellent fluidity and good permeability; the anti-settling effect of the viscosity modifier can make the grouting material have high fluidity without bleeding and segregation. The scientific combination and synergy of the present application make the grouting material for rubble masonry reinforcement have the characteristics of strong adhesion, good impermeability, micro-expansion, good fluidity, strong permeability, and good long-term durability, which is suitable for rubble masonry reinforcement engineering and can prolong the service life of rubble masonry.

[0019] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0020] 1) The grouting material for rubble masonry reinforcement of the present application can have high fluidity, low viscosity, and no bleeding and segregation through the water-reducing effect of the superplasticizer, the ball bearing lubrication provided by the floating beads, and the anti-settling effect of the viscosity modifier, has suitable thixotropy during reinforcement construction, has good fluidity under pressure, and the grouting material can easily penetrate into the masonry, so that the voids are filled; has good thixotropy under no pressure, the grouting material does not bleed and segregate, can ensure that the grouting space is full and not empty, and the stable grouting state can ensure the good quality of the reinforced masonry as a whole.

[0021] 2) The grouting material for rubble masonry reinforcement of the present application improves the impermeability of the cement paste and enhances the adhesive force of the cement stone by adding polymers, greatly enhances the adhesive force between the grouting material and the existing rubble masonry structure, can form a whole to work together, and is modified by water-based epoxy, so that the polymer has the advantages of high strength, corrosion resistance, strong adhesion, and water resistance of epoxy resin, so that the reinforced rubble masonry structure has good overall corrosion resistance and can resist corrosion by hydrogen sulfide, weak acid, sulfate, etc., and has excellent durability.

[0022] 3)The grouting material for reinforcing rubble masonry of the present application generates certain limited expansion through the chemical reaction of the expanding agent or the reaction with other components in the cement stone, which reduces shrinkage and reduces later cracking, and the generated ettringite crystals can play the role of filling and blocking capillary holes, which can improve the mechanical interlocking force with the masonry pores, thereby improving the overall bonding performance. DETAILED DESCRIPTION

[0023] The present application is further illustrated by the following examples, but the scope of protection of the present application is not limited to the following examples.

[0024] In the following specific examples, each raw material is a commercialized raw material directly purchased unless otherwise specified.

[0025] Example 1

[0026] PO52.5 grade cement 60 parts, calcium sulphoaluminate expanding agent 12 parts, Class I fly ash 10 parts, silica fume (0.3 μm) 10 parts, sodium silicate 2 parts, melamine superplasticizer 2 parts, ZTC-018 (water-based epoxy modified acrylic resin) 2 parts, viscosity modifier (sarcosine: L-galactose = 4:6) 0.02 parts, 120-200 mesh floating beads 4 parts, and silicone defoaming agent 0.3 parts.

[0027] Example 2

[0028] PO52.5 grade cement 65 parts, calcium sulphoaluminate expanding agent 8 parts, Class I fly ash 15 parts, silica fume (0.3 μm) 8 parts, sodium silicate 3 parts, melamine superplasticizer 3 parts, ZTC-018 (water-based epoxy modified acrylic resin) 5 parts, viscosity modifier (sarcosine: L-galactose = 3:7) 0.1 parts, 120-200 mesh floating beads 8 parts, and silicone defoaming agent 0.8 parts.

[0029] Example 3

[0030] PO52.5 grade cement 70 parts, calcium sulphoaluminate expanding agent 8 parts, Class I fly ash 10 parts, silica fume (0.3 μm) 5 parts, sodium silicate 5 parts, melamine superplasticizer 1 part, ZTC-018 (water-based epoxy modified acrylic resin) 8 parts, viscosity modifier (sarcosine: L-galactose = 4:6) 0.05 parts, 120-200 mesh floating beads 6 parts, and silicone defoaming agent 0.8 parts.

[0031] Example 4

[0032] PO 52.5 grade cement 65 parts, calcium sulphoaluminate expansive agent 10 parts, Class I fly ash 20 parts, silica fume (0.3 μm) 5 parts, sodium silicate 1 part, melamine superplasticizer 3 parts, ZTC-018 (water-based epoxy-modified acrylic resin) 2 parts, viscosity modifier (sarcosine : L-galactose = 5 : 5) 0.2 parts, 120-200 mesh floating bead 4 parts, silicone defoaming agent 0.5 part.

[0033] Comparative Example 1

[0034] The difference between this comparative example and Example 1 is that it does not contain ZTC-018. Specifically, it is:

[0035] PO 52.5 grade cement 60 parts, calcium sulphoaluminate expansive agent 12 parts, Class I fly ash 10 parts, silica fume (0.3 μm) 10 parts, sodium silicate 2 parts, melamine superplasticizer 2 parts, ZTC-018 (water-based epoxy-modified acrylic resin) 0 parts, viscosity modifier (sarcosine : L-galactose = 4 : 6) 0.02 parts, 120-200 mesh floating bead 4 parts, silicone defoaming agent 0.3 part.

[0036] Comparative Example 2

[0037] The difference between this comparative example and Example 1 is that it does not contain calcium sulphoaluminate expansive agent. Specifically, it is:

[0038] PO 52.5 grade cement 60 parts, calcium sulphoaluminate expansive agent 0 parts, Class I fly ash 10 parts, silica fume (0.3 μm) 10 parts, sodium silicate 2 parts, melamine superplasticizer 2 parts, ZTC-018 (water-based epoxy-modified acrylic resin) 2 parts, viscosity modifier (sarcosine : L-galactose = 4 : 6) 0.02 parts, 120-200 mesh floating bead 4 parts, silicone defoaming agent 0.3 part.

[0039] Comparative Example 3

[0040] The difference between this comparative example and Example 1 is that it does not contain viscosity modifier. Specifically, it is:

[0041] PO 52.5 grade cement 60 parts, calcium sulphoaluminate expansive agent 12 parts, Class I fly ash 10 parts, silica fume (0.3 μm) 10 parts, sodium silicate 2 parts, melamine superplasticizer 2 parts, ZTC-018 (water-based epoxy-modified acrylic resin) 2 parts, viscosity modifier (sarcosine : L-galactose = 4 : 6) 0 parts, 120-200 mesh floating bead 4 parts, silicone defoaming agent 0.3 part.

[0042] Comparative Example 4

[0043] The difference between this comparative example and Example 1 is that it does not contain floating bead. Specifically, it is:

[0044] PO 52.5 grade cement 60 parts, calcium sulphoaluminate expansive agent 12 parts, Class I fly ash 10 parts, silica fume (0.3 μm) 10 parts, sodium silicate 2 parts, melamine superplasticizer 2 parts, ZTC-018 (water-based epoxy-modified acrylic resin) 2 parts, viscosity modifier (sarcosine : L-galactose = 4 : 6) 0.02 parts, 120-200 mesh floating bead 0 parts, silicone defoaming agent 0.3 parts.

[0045] Comparative Example 5

[0046] This comparative example differs from Example 1 in that ZTC-018 (water-based epoxy-modified acrylic resin) is replaced with butadiene and styrene copolymer PSB150 styrene-butadiene rubber powder (purchased from the United States of America's Hansen Company). Specifically:

[0047] PO 52.5 grade cement 60 parts, calcium sulphoaluminate expansive agent 12 parts, Class I fly ash 10 parts, silica fume (0.3 μm) 10 parts, sodium silicate 2 parts, melamine superplasticizer 2 parts, PSB150 styrene-butadiene rubber powder 2 parts, viscosity modifier (sarcosine : L-galactose = 4 : 6) 0.02 parts, 120-200 mesh floating bead 4 parts, silicone defoaming agent 0.3 parts.

[0048] Comparative Example 6

[0049] This comparative example differs from Example 1 in that it is a single viscosity modifier. Specifically:

[0050] PO 52.5 grade cement 60 parts, calcium sulphoaluminate expansive agent 12 parts, Class I fly ash 10 parts, silica fume (0.3 μm) 10 parts, sodium silicate 2 parts, melamine superplasticizer 2 parts, ZTC-018 (water-based epoxy-modified acrylic resin) 2 parts, viscosity modifier (sarcosine : L-galactose = 10 : 0) 0.02 parts, 120-200 mesh floating bead 4 parts, silicone defoaming agent 0.3 parts.

[0051] Comparative Example 7

[0052] This comparative example differs from Example 1 in that it is a single viscosity modifier. Specifically:

[0053] PO 52.5 grade cement 60 parts, calcium sulphoaluminate expansive agent 12 parts, Class I fly ash 10 parts, silica fume (0.3 μm) 10 parts, sodium silicate 2 parts, melamine superplasticizer 2 parts, ZTC-018 (water-based epoxy-modified acrylic resin) 2 parts, viscosity modifier (sarcosine : L-galactose = 0 : 10) 0.02 parts, 120-200 mesh floating bead 4 parts, silicone defoaming agent 0.3 parts.

[0054] The construction is mixed with the above examples and comparative examples respectively, and then water is added and stirred to form a slurry for use (the weight ratio of water to the dry powder mortar product is 0.28). The performance test results are shown in Table 1. The bleeding rate, fluidity and free expansion rate are tested according to the standard JTG 3420 “Cement and Cement Concrete Test Procedures for Highway Engineering”. The bonding strength is tested according to the standard GB50728 “Technical Specification for Safety Identification of Engineering Structure Reinforcing Materials”. The flexural strength and compressive strength are tested according to the standard GB / T 17671 “Cement Mortar Strength Test Method (ISO Method)”. The impermeable pressure is tested according to the standard JGJ 70 “Standard for Building Mortar Basic Performance Test Method”.

[0055] Table 1 Performance test results of examples and comparative examples

[0056]

[0057] The results show that the grouting material for rough stone masonry reinforcement of examples 1, 2, 3 and 4 has good working performance, no bleeding, slight expansion, high compressive strength and excellent bonding strength.

[0058] The bonding strength of comparative example 1 decreases significantly, and the impermeable pressure also decreases, indicating that the water-based epoxy modified acrylic resin has a significant effect on the bonding strength and impermeability. The bonding strength and impermeable pressure of comparative example 5 also decrease, indicating that the type of polymer (or whether it is modified by epoxy) also has an effect on the bonding strength and impermeability.

[0059] The expansion rate of comparative example 2 is negative, indicating that the expansion agent has a great effect on the expansion performance.

[0060] Comparative examples 3, 4, 6 and 7 have poor workability and bleeding, resulting in a decrease in bonding strength and impermeability, indicating that the proportion and type of viscosity modifier and the effect of the floating beads on the workability of the grouting material are great, and it also affects other properties.

[0061] In summary, a reasonable ratio is necessary to prepare a grouting material with excellent performance. The grouting material for rough stone masonry reinforcement of the present application can achieve the best synergistic effect when the components reach a scientific balance, and has the characteristics of strong adhesion, good impermeability, slight expansion, good fluidity, long-term durability, excellent workability and mechanical properties, and is suitable for rough stone masonry reinforcement engineering. It can effectively solve the problems of post-cracking and durability of reinforced rough stone masonry, and prolong the service life of rough stone masonry.

Claims

1. A grout for rubble masonry reinforcement, characterized in that: The cement 60~70 parts by mass; the expanding agent 8~12 parts by mass; the fly ash 10~20 parts by mass; the silica ash 5~10 parts by mass; the silicate 1~5 parts by mass; the superplasticizer 1~3 parts by mass; the water-based epoxy modified acrylic resin 2~8 parts by mass; the viscosity modifier 0.02~0.2 parts by mass; the floating bead 4~8 parts by mass; the defoaming agent 0.3~0.8 parts by mass. The viscosity modifier is a complex of sarcosine and L-galactose; the mass percentage of sarcosine and L-galactose is 30~60%:40~70%. The cement is ordinary Portland cement, and the strength grade is 52.5 or 42.5; the expanding agent is calcium sulphoaluminate type expanding agent; the fly ash is grade I or grade II power plant fly ash. The particle size of the silica ash is 0.2~0.5μm. The silicate is at least one of sodium silicate, lithium silicate and potassium silicate. The superplasticizer is at least one of melamine high efficiency water reducing agent and polycarboxylic acid high performance water reducing agent. The specification of the floating bead is 120~200 mesh. The defoaming agent is silicone defoaming agent. ​ ​ ​ ​ 2. The casting slurry according to claim 1, characterized in that: ​ 3. The casting slurry according to claim 1, characterized in that: ​ 4. The casting slurry according to claim 1, characterized in that: ​ 5. The casting slurry of claim 1, wherein: ​ 6. The casting slurry of claim 1, wherein: ​ 7. The casting slurry of claim 1, wherein: ​

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