Disclosure of Invention
Aiming at the problems of slow development of early strength, poor freeze-thaw durability and the like of the existing grouting material, the invention provides the grouting material for the large bridge bearing and the preparation method thereof.
In order to achieve the purpose, the invention adopts the following technical scheme:
the grouting material for the large bridge support comprises the following raw material components in parts by mass: 20-40 parts of cement; 30-60 parts of stones; 20-45 parts of natural sand; 3-6 parts of fly ash; 0.3-2 parts of polyacrylate-polyurethane copolymer emulsion; 1-4 parts of gypsum; 0.4-0.8 part of hardening accelerator; 0.08-0.2 part of retarder; 0.02-0.08 part of defoaming agent; 0.1-0.4 part of water reducing agent and 6-12 parts of water.
Compared with the prior art, the grouting material for the large bridge bearing provided by the invention has the advantages that cement, gypsum and a hardening accelerator are compounded for use, the hydration is fast, the free water in the grouting material is consumed, the demulsification and solidification process of the polyacrylate-polyurethane copolymer emulsion is accelerated, the early strength of the grouting material is increased fast, and the early strength of the grouting material is improved. Meanwhile, the gypsum can form ettringite and the fly ash to play a role in filling pores under the combined action in the cement hydration process, so that the density of the grouting material is improved, and the early strength, the crack resistance and the durability are improved. Secondly, the stones and the natural sand play roles in maintaining the shape and increasing the strength in the grouting material, the shrinkage rate and the thermal expansion coefficient of the grouting material can be reduced, and gaps between the stones and the natural sand are filled by the fly ash and the polyacrylate-polyurethane copolymer emulsion through the grading principle, so that the compressive strength and the flexural strength of the grouting material are improved. In addition, the polyacrylate-polyurethane copolymer emulsion is added to modify the grouting material, cement hydrate and polymer form a film to form a composite gel phase, so that the internal bonding capacity of the grouting material is increased, the number of cracks and pores of the grouting material is reduced, the impermeability and freeze-thaw resistance are enhanced, and the compactness and durability of the grouting material are improved.
Further, the solid content of the polyacrylate-polyurethane copolymer emulsion is 30-50%, wherein the molar ratio of a polyurethane part to a polyacrylate part in a polyacrylate-polyurethane copolymer chain segment is (10-20): (80-90). The polyacrylate-polyurethane copolymer is ensured to be cured quickly and has good bonding strength and toughness.
The polyacrylate-polyurethane copolymer emulsion, the water reducing agent and the defoaming agent act together to further improve the dispersibility of cement particles, improve the workability of the grouting material, reduce the water consumption, reduce harmful pores such as capillary pores of cement and improve the compactness and the anti-permeability of the grouting material. At the same time. Active gene in polymer molecule and free Ca in cement hydration process2+、A13+、Fe2+The plasma is exchanged to form a special bridge bond, and the physical and chemical adsorption is carried out around the cement particles, so that the deformation bearing capacity is increased, the possibility of generating micro-gaps is greatly reduced, the generation and development of cracks are inhibited, and the grouting material has good impact resistance toughness and strength. In addition, the polymer reacts to form a tough and compact film which is filled between cement particles and aggregate, and due to the sealing effect of the polymer film, a channel which is connected with the outside is isolated, the invasion of moisture or air is prevented, and the freeze-thaw resistance is improved.
Further, the polyacrylate-polyurethane copolymer emulsion is prepared by polymerizing polyurethane, diacetone acrylamide, methacrylic acid, methyl methacrylate and butyl acrylate, wherein the polyurethane is prepared by reacting polypropylene glycol 600 with castor oil, the polyacrylate-polyurethane copolymer emulsion well avoids the defects of poor brittleness, toughness and long polyurethane curing time of polyacrylate, and has the advantages of quick polyacrylate curing and strong polyurethane toughness.
Further, the molar ratio of the polypropylene glycol 600 to the castor oil is 1: 1; the molar ratio of diacetone acrylamide to methacrylic acid to methyl methacrylate to butyl acrylate is 1 (2.5-3.8) to (20-23) to (22-25). The method comprises the steps of firstly preparing polyurethane by using polypropylene glycol 600 and castor oil as raw materials, then using diacetone acrylamide and methacrylic acid as functional monomers, using methyl methacrylate as hard monomers, using butyl acrylate as soft monomers and carrying out continuous polymerization reaction with the obtained polyurethane to obtain polyacrylate-polyurethane copolymer emulsion, so that the obtained polyacrylate-polyurethane copolymer emulsion well avoids the defects of poor brittleness and toughness of polyacrylate and long polyurethane curing time, and has the advantages of quick polyacrylate curing and strong polyurethane toughness. The polyacrylate-polyurethane copolymer emulsion is used in grouting material, can better form a composite gel phase with cement hydrate, and improves the physical, mechanical and durability properties of the grouting material.
Further, the polymerization temperature is 72-93 ℃, and the time is 8-10 h; the reaction temperature is 60-90 ℃, and the reaction time is 4-8 h.
Further, the preparation method of the polyacrylate-polyurethane copolymer emulsion comprises the following steps:
s1: the polyurethane is prepared by taking polypropylene glycol 600 and castor oil as raw materials to react;
s2: and mixing the polyurethane with diacetone acrylamide, methacrylic acid, methyl methacrylate and butyl acrylate, adding a cross-linking agent, an initiator and an emulsifier, and polymerizing to obtain the polyacrylate-polyurethane copolymer emulsion.
Further, in step S2, the crosslinking agent is adipic acid dihydrazide; the initiator is ammonium persulfate; the emulsifier is one of sodium dodecyl benzene sulfonate, sodium dodecyl sulfate or octyl phenol polyoxyethylene ether. The addition amounts of the cross-linking agent, the initiator and the emulsifier are all conventional amounts.
Furthermore, the cement is 72.5-grade quick-hardening sulphoaluminate cement, and the early strength of the grouting material is ensured.
Furthermore, the stones are crushed stones with the particle size of 5-10 mm and the apparent density of 2711kg.m-3Bulk density of 1540kg.m-3(ii) a The particle size of the natural sand is 0.5-1.8 mm, the fineness modulus is 2.85, and the stones and the natural sand are used as aggregates and play roles in maintaining the shape and increasing the strength in the grouting material.
Further, the fly ash is grade II fly ash; the gypsum is dihydrate gypsum, and the purity is more than or equal to 95%. The fly ash is adhered to the surfaces of aggregate and cement particles through an interface effect, and is uniformly distributed in the grouting material through a micro-aggregate effect to fill pores and capillary holes, so that the structure of an interface transition region of the aggregate and the set cement is improved, the compactness of the interface transition region is improved, a bleeding channel of the interface of the set cement and the aggregate is reduced, and the crack resistance and the durability of the grouting material are improved. The ettringite formed by the dihydrate gypsum in the cement hydration process and the fly ash play a role in filling pores, improve the density of the grouting material, and improve the impermeability and the freeze-thaw resistance under the combined action of the copolymerized emulsion.
Further, the hardening accelerator is a mixture of calcium formate and sodium nitrite in a mass ratio of 1: 0.8-1.2; the retarder is a mixture of sodium gluconate and boric acid in a mass ratio of 1: 3.2-3.8; the defoaming agent is a powder defoaming agent; the water reducing agent is a polycarboxylic acid high-efficiency water reducing agent. The addition of the hardening accelerator and the retarder properly delays the hydration of cement, reduces the crack generation of the grouting material, improves the stability of the grouting material, and effectively improves the early strength of the grouting material under the combined action of the cement and the gypsum; and the water reducing agent and the defoaming agent are matched for use, so that the aggregation of cement particles can be prevented, the quantity of slurry bubbles is reduced, the fluidity and compactness of the grouting material are improved, and the workability and impermeability of the grouting material are effectively improved.
The invention also provides a preparation method of the grouting material for the large bridge bearing, which comprises the following steps:
s1: mixing 40-60 wt% of the cement and 40-60 wt% of water with the stones and the retarder to obtain a premix;
s2: adding the residual cement, the residual water, the natural sand, the fly ash, the gypsum, the hardening accelerator, the defoamer and the water reducer into the obtained premix, stirring and adding the polyacrylate-polyurethane copolymer emulsion to obtain the grouting material.
Compared with the prior art, the preparation method of the grouting material for the large bridge bearing provided by the invention has the advantages that the process is simple, the operation is convenient, the cement, the stones, the retarder, the natural sand, the fly ash, the gypsum, the hardening accelerator, the defoaming agent, the water reducing agent and the copolymerization emulsion are sequentially mixed to obtain the grouting material, and the obtained grouting material has the characteristics of high hardening speed, good early strength, high compactness, good freezing resistance and durability and the like.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The embodiment of the invention provides a grouting material for a large bridge bearing, which comprises the following raw material components in parts by weight: 20-40 parts of cement; 30-60 parts of stones; 20-45 parts of natural sand; 3-6 parts of fly ash; 0.3-2 parts of polyacrylate-polyurethane copolymer emulsion; 1-4 parts of gypsum; 0.4-0.8 part of hardening accelerator; 0.08-0.2 part of retarder; 0.02-0.08 part of defoaming agent; 0.1-0.4 part of water reducing agent and 6-12 parts of water.
According to the invention, the polyacrylate-polyurethane copolymer emulsion is added to modify the grouting material, cement hydrate and polymer form a film to form a composite gelled phase, pebbles and natural sand are used as aggregates, fly ash is used as an admixture and a micro-aggregate to interact with gypsum and a functional assistant, so that the physical, mechanical and durability properties of the grouting material are improved, and the obtained grouting material has high early strength, good compressive strength, breaking strength and freeze-thaw durability.
In order to better illustrate the grouting material for a large bridge bearing provided by the embodiment of the invention, the following further illustrates the grouting material by the embodiment.
Example 1
The grouting material for the large bridge support comprises the following raw material components in parts by mass: 30 parts of 72.5-grade quick-hardening sulphoaluminate cement; 30 parts of stones; 28 parts of natural sand; 4 parts of class II fly ash; 1.2 parts of polyacrylate-polyurethane copolymer emulsion (the solid content is 50%); 1.5 parts of dihydrate gypsum; 0.5 part of hardening accelerator; 0.1 part of retarder; 0.04 part of AGITANR P803 powder antifoaming agent; 0.3 part of polycarboxylic acid high-efficiency water reducing agent and 9.6 parts of water,
wherein the hardening accelerator is a mixture of calcium formate and sodium nitrite with the mass ratio of 1: 1.2; the retarder is a mixture of sodium gluconate and boric acid in a mass ratio of 1: 3.8;
the solid content of the polyacrylate-polyurethane copolymer emulsion is 50%, and the molar ratio of the polyurethane part to the polyacrylate part in the polyacrylate-polyurethane copolymer chain segment is 20: 80, the specific preparation method comprises the following steps:
s1: taking polypropylene glycol 600 and castor oil with a molar ratio of 1:1 as raw materials, and reacting at 80 ℃ to obtain polyurethane;
s2: mixing the obtained polyurethane with diacetone acrylamide, methacrylic acid, methyl methacrylate and butyl acrylate in a molar ratio of 1:3.2:21:24, and polymerizing at 80 ℃ by using adipic dihydrazide as a cross-linking agent, ammonium persulfate as an initiator and sodium dodecyl benzene sulfonate as an emulsifier to obtain the polyacrylate-polyurethane copolymer emulsion.
The preparation method of the grouting material comprises the following steps:
s1: mixing 50 wt% of the 72.5-grade quick-hardening sulphoaluminate cement and 50 wt% of water with stones and a retarder to obtain a premix;
s2: adding the residual 72.5-grade quick-hardening sulphoaluminate cement, the residual water, the natural sand, the II-grade fly ash, the dihydrate gypsum, the hardening accelerator, the AGITANR P803 powder defoamer and the polycarboxylic acid high-efficiency water reducing agent into the obtained premix, stirring, adding the polyacrylate-polyurethane copolymer emulsion, and continuously stirring until the system is uniform to obtain the grouting material.
Example 2
The grouting material for the large bridge support comprises the following raw material components in parts by mass: 28 parts of 72.5 grade quick hardening sulphoaluminate cement; 38 parts of stones; 30 parts of natural sand; 3 parts of grade II fly ash; 1.7 parts of polyacrylate-polyurethane copolymer emulsion (the solid content is 40%); 2 parts of dihydrate gypsum; 0.5 part of hardening accelerator; 0.2 part of retarder; 0.04 part of AGITANR P803 powder antifoaming agent; 0.2 part of polycarboxylic acid high-efficiency water reducing agent and 9.5 parts of water,
wherein the hardening accelerator is a mixture of calcium formate and sodium nitrite with the mass ratio of 1: 0.8; the retarder is a mixture of sodium gluconate and boric acid in a mass ratio of 1: 3.2;
the solid content of the polyacrylate-polyurethane copolymer emulsion is 40%, and the molar ratio of the polyurethane part to the polyacrylate part in the polyacrylate-polyurethane copolymer chain segment is 10: 90, the specific preparation method is as follows:
s1: taking polypropylene glycol 600 and castor oil with a molar ratio of 1:1 as raw materials, and reacting at 70 ℃ to obtain polyurethane;
s2: mixing the obtained polyurethane with diacetone acrylamide, methacrylic acid, methyl methacrylate and butyl acrylate in a molar ratio of 1:2.5:20:22, and polymerizing at 72 ℃ by using adipic dihydrazide as a cross-linking agent, ammonium persulfate as an initiator and sodium dodecyl sulfate as an emulsifier to obtain the polyacrylate-polyurethane copolymer emulsion.
The preparation method of the grouting material comprises the following steps:
s1: mixing 40wt% of the 72.5-grade quick-hardening sulphoaluminate cement and 40wt% of water with stones and a retarder to obtain a premix;
s2: adding the residual 72.5-grade quick-hardening sulphoaluminate cement, the residual water, the natural sand, the II-grade fly ash, the dihydrate gypsum, the hardening accelerator, the AGITANR P803 powder defoamer and the polycarboxylic acid high-efficiency water reducing agent into the obtained premix, stirring, adding the polyacrylate-polyurethane copolymer emulsion, and continuously stirring until the system is uniform to obtain the grouting material.
Example 3
The grouting material for the large bridge support comprises the following raw material components in parts by mass: 26 parts of 72.5-grade quick-hardening sulphoaluminate cement; 32 parts of stones; 28 parts of natural sand; 6 parts of II-grade fly ash; 0.5 part of polyacrylate-polyurethane copolymer emulsion (the solid content is 30 percent); 1 part of dihydrate gypsum; 0.8 part of hardening accelerator; 0.08 part of retarder; 0.04 part of AGITANR P803 powder antifoaming agent; 0.4 part of polycarboxylic acid high-efficiency water reducing agent and 9.4 parts of water,
wherein the hardening accelerator is a mixture of calcium formate and sodium nitrite with the mass ratio of 1: 1; the retarder is a mixture of sodium gluconate and boric acid in a mass ratio of 1: 3.5;
the solid content of the polyacrylate-polyurethane copolymer emulsion is 30%, and the molar ratio of the polyurethane part to the polyacrylate part in the polyacrylate-polyurethane copolymer chain segment is 15: 85, the specific preparation method is as follows:
s1: taking polypropylene glycol 600 and castor oil with a molar ratio of 1:1 as raw materials, and reacting at 90 ℃ to obtain polyurethane;
s2: mixing the obtained polyurethane with diacetone acrylamide, methacrylic acid, methyl methacrylate and butyl acrylate in a molar ratio of 1:2.5:23:25, and polymerizing at 93 ℃ by using adipic dihydrazide as a crosslinking agent, ammonium persulfate as an initiator and sodium dodecyl sulfate as an emulsifier to obtain the polyacrylate-polyurethane copolymer emulsion.
The preparation method of the grouting material comprises the following steps:
s1: mixing 60 wt% of the 72.5-grade quick-hardening sulphoaluminate cement and 60 wt% of water with stones and a retarder to obtain a premix;
s2: adding the residual 72.5-grade quick-hardening sulphoaluminate cement, the residual water, the natural sand, the II-grade fly ash, the dihydrate gypsum, the hardening accelerator, the AGITANR P803 powder defoamer and the polycarboxylic acid high-efficiency water reducing agent into the obtained premix, stirring, adding the polyacrylate-polyurethane copolymer emulsion, and continuously stirring until the system is uniform to obtain the grouting material.
Example 4
The grouting material for the large bridge support comprises the following raw material components in parts by mass: 20 parts of 72.5 grade quick hardening sulphoaluminate cement; 30 parts of stones; 20 parts of natural sand; 3 parts of grade II fly ash; 0.3 part of polyacrylate-polyurethane copolymer emulsion (the solid content is 50 percent); 1 part of dihydrate gypsum; 0.4 part of hardening accelerator; 0.08 part of retarder; 0.03 part of AGITANR P803 powder antifoaming agent; 0.2 part of polycarboxylic acid high-efficiency water reducing agent and 6 parts of water,
wherein the hardening accelerator is a mixture of calcium formate and sodium nitrite with the mass ratio of 1: 1.2; the retarder is a mixture of sodium gluconate and boric acid in a mass ratio of 1: 3.2;
the solid content of the polyacrylate-polyurethane copolymer emulsion is 50%, and the molar ratio of the polyurethane part to the polyacrylate part in the polyacrylate-polyurethane copolymer chain segment is 20: 90, the specific preparation method is as follows:
s1: taking polypropylene glycol 600 and castor oil with a molar ratio of 1:1 as raw materials, and reacting at 90 ℃ to obtain polyurethane;
s2: mixing the obtained polyurethane with diacetone acrylamide, methacrylic acid, methyl methacrylate and butyl acrylate in a molar ratio of 1:3.8:22:22, and polymerizing at 93 ℃ by using adipic dihydrazide as a cross-linking agent, ammonium persulfate as an initiator and octylphenol polyoxyethylene ether as an emulsifier to obtain the polyacrylate-polyurethane copolymer emulsion.
The preparation method of the grouting material comprises the following steps:
s1: mixing 40wt% of the 72.5-grade quick-hardening sulphoaluminate cement and 50 wt% of water with stones and a retarder to obtain a premix;
s2: adding the residual 72.5-grade quick-hardening sulphoaluminate cement, the residual water, the natural sand, the II-grade fly ash, the dihydrate gypsum, the hardening accelerator, the AGITANR P803 powder defoamer and the polycarboxylic acid high-efficiency water reducing agent into the obtained premix, stirring, adding the polyacrylate-polyurethane copolymer emulsion, and continuously stirring until the system is uniform to obtain the grouting material.
Example 5
The grouting material for the large bridge support comprises the following raw material components in parts by mass: 35 parts of 72.5-grade quick-hardening sulphoaluminate cement; 50 parts of stones; 40 parts of natural sand; 5 parts of II-grade fly ash; 2 parts of polyacrylate-polyurethane copolymer emulsion (solid content is 50%); 3 parts of dihydrate gypsum; 0.8 part of hardening accelerator; 0.2 part of retarder; 0.08 part of AGITANR P803 powder antifoaming agent; 0.4 part of polycarboxylic acid high-efficiency water reducing agent and 12 parts of water,
wherein the hardening accelerator is a mixture of calcium formate and sodium nitrite with the mass ratio of 1: 0.8; the retarder is a mixture of sodium gluconate and boric acid in a mass ratio of 1: 3.8;
the solid content of the polyacrylate-polyurethane copolymer emulsion is 50%, and the molar ratio of the polyurethane part to the polyacrylate part in the polyacrylate-polyurethane copolymer chain segment is 10: 80, the specific preparation method comprises the following steps:
s1: taking polypropylene glycol 600 and castor oil with a molar ratio of 1:1 as raw materials, and reacting at 60 ℃ to obtain polyurethane;
s2: mixing the obtained polyurethane with diacetone acrylamide, methacrylic acid, methyl methacrylate and butyl acrylate in a molar ratio of 1:2.5:20:25, and polymerizing at 85 ℃ by using adipic dihydrazide as a cross-linking agent, ammonium persulfate as an initiator and sodium dodecyl sulfate as an emulsifier to obtain the polyacrylate-polyurethane copolymer emulsion.
The preparation method of the grouting material comprises the following steps:
s1: mixing 60 wt% of the 72.5-grade quick-hardening sulphoaluminate cement and 50 wt% of water with stones and a retarder to obtain a premix;
s2: adding the residual 72.5-grade quick-hardening sulphoaluminate cement, the residual water, the natural sand, the II-grade fly ash, the dihydrate gypsum, the hardening accelerator, the AGITANR P803 powder defoamer and the polycarboxylic acid high-efficiency water reducing agent into the obtained premix, stirring, adding the polyacrylate-polyurethane copolymer emulsion, and continuously stirring until the system is uniform to obtain the grouting material.
Example 6
The grouting material for the large bridge support comprises the following raw material components in parts by mass: 40 parts of 72.5-grade quick-hardening sulphoaluminate cement; 60 parts of stones; 45 parts of natural sand; 4 parts of class II fly ash; 2 parts of polyacrylate-polyurethane copolymer emulsion (the solid content is 30%); 4 parts of dihydrate gypsum; 0.5 part of hardening accelerator; 0.1 part of retarder; 0.02 part of AGITANR P803 powder antifoaming agent; 0.1 part of polycarboxylic acid high-efficiency water reducing agent and 12 parts of water,
wherein the hardening accelerator is a mixture of calcium formate and sodium nitrite with the mass ratio of 1: 1.2; the retarder is a mixture of sodium gluconate and boric acid in a mass ratio of 1: 3.8;
the solid content of the polyacrylate-polyurethane copolymer emulsion is 30%, and the molar ratio of the polyurethane part to the polyacrylate part in the polyacrylate-polyurethane copolymer chain segment is 10: 80, the specific preparation method comprises the following steps:
s1: taking polypropylene glycol 600 and castor oil with a molar ratio of 1:1 as raw materials, and reacting at 70 ℃ to obtain polyurethane;
s2: mixing the obtained polyurethane with diacetone acrylamide, methacrylic acid, methyl methacrylate and butyl acrylate in a molar ratio of 1:3:21:23, and polymerizing at 72 ℃ by using adipic dihydrazide as a cross-linking agent, ammonium persulfate as an initiator and sodium dodecyl benzene sulfonate as an emulsifier to obtain the polyacrylate-polyurethane copolymer emulsion.
The preparation method of the grouting material comprises the following steps:
s1: mixing 50 wt% of the 72.5-grade quick-hardening sulphoaluminate cement and 50 wt% of water with stones and a retarder to obtain a premix;
s2: adding the residual 72.5-grade quick-hardening sulphoaluminate cement, the residual water, the natural sand, the II-grade fly ash, the dihydrate gypsum, the hardening accelerator, the AGITANR P803 powder defoamer and the polycarboxylic acid high-efficiency water reducing agent into the obtained premix, stirring, adding the polyacrylate-polyurethane copolymer emulsion, and continuously stirring until the system is uniform to obtain the grouting material.
In order to better illustrate the technical solution of the present invention, further comparison is made below by means of a comparative example and an example of the present invention.
Comparative example 1
A grouting material for a large bridge bearing is prepared by replacing polyacrylate-polyurethane copolymer emulsion with polyacrylate emulsion (emulsion prepared by adopting acrylic acid monomer in example 1) with the same amount on the basis of example 1, and obtaining the grouting material by adopting the preparation method the same as that of example 1, wherein other components are the same as those in example 1.
Comparative example 2
A grouting material for a large bridge support is prepared by replacing polyacrylate-polyurethane copolymer emulsion with equal amount of epoxy resin emulsion (conventional emulsion) on the basis of example 1, and obtaining the grouting material by the same preparation method as in example 1, wherein other components are the same as in example 1.
Comparative example 3
A grouting material for a large bridge bearing is prepared by replacing polyacrylate-polyurethane copolymer emulsion with equal amount of polyurethane emulsion (prepared by reacting polypropylene glycol 600 and castor oil) on the basis of example 1, and obtaining the grouting material by the same preparation method as example 1, wherein the other components are the same as example 1.
Comparative example 4
A grouting material for a large bridge bearing is prepared by replacing fly ash with equivalent gangue powder on the basis of example 1, and obtaining the grouting material by adopting the same preparation method as in example 1, wherein other components are the same as those in example 1.
In order to better illustrate the characteristics of the grouting material for the large bridge bearing provided by the embodiment of the invention, the grouting materials prepared in the embodiments 1-6 and the comparative examples 1-4 are subjected to performance tests, the compressive strength is determined according to the JTG E30-2005 and executed in GB 50504-. The test results are shown in table 1.
TABLE 1
According to the data, the grouting material for the large bridge support has high early strength, the difference value between the compressive strength 1d and the compressive strength 28d is 9.3-13.7MPa, the strength growth speed is high, and the setting speed is high. The grouting material for the large bridge support has good bending strength and frost resistance, and shows that the grouting material for the large bridge support has certain superiority in engineering rush repair in extremely severe cold areas.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents or improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.