A high-belite sulfoaluminate special cementitious material for cement-based high-early-strength non-shrinkage grouting materials

Abstract

The invention relates to a high-belite sulfoaluminate special gelatinizing material for a cement based high early strength shrinkage-free grouting material. The material is obtained by dry blending of, by weight, 60-70 parts of high-belite sulfoaluminate cement clinker powder, 5-10 parts of alpha type high strength gypsum powder, 5-10 parts of beta type gypsum powder and 15-20 parts of superfine powdered coal. The alkalinity coefficient Cm value of the high-belite sulfoaluminate cement clinker is 50-60%, the aluminum sulfur ratio P value is 1.3-1.5, and fSO3 is 5-7%; the high-belite sulfoaluminate cement clinker is prepared from, by weight, 30-35% of C2S, 50-60% of C4A3S, 9-12% of CaSO4 and 1.3-1.8% of C4AF. The 2h strength of the special gelatinizing material can reach 25 MPa or more, thematerial has the certain plasticity and rigidity micro-expanding performance, and the link of adding an expanding agent can be omitted when the grouting material is prepared.

Description

technical field [0001] The invention belongs to the technical field of cement-based materials, in particular to a high-belite special sulfoaluminate cementitious material used for cement-based high-early-strength non-shrinkage grouting materials. Background technique [0002] Non-shrinkage grouting material is a cement-based material that can be poured and grouted in narrow gaps and dense reinforcement under the condition of no vibration. It is mainly used for anchor bolt anchorage, emergency repair of airstrip, fixation of nuclear power equipment, reinforcement of road and bridge engineering, secondary grouting of equipment foundation, crack treatment of old concrete structure, installation of electromechanical equipment, installation of track and steel structure, installation of wall structure For projects such as thickening and repair of leakage and seepage, grouting construction is also required for the steel sleeve connection between prefabricated building components. ...

AI Technical Summary

Problems solved by technology

The current non-shrinkage grouting materials cannot meet these requirements at the same time, especially the strength in the early age is not enough, resulting in construction quality defects

Chinese Patent Publication No. CN103482928A discloses a high-performance non-shrinkage cement-based grouting material. Portland cement is used as the main cementitious material, and the mechanical strength of the grouting material is greatly enhanced by adding thermosetting resin fibers. The strength in one day is about 40 MPa, 28 The daily strength is about 90MPa, but this method requires a complicated preparation process, and the early age strength of 2-4 hours is not mentioned

Chinese Patent Publication No. CN107176812A discloses a high-strength non-shrinkage grouting material. The composite of Portland cement and sulphoaluminate cement is used as the main cementitious material. In order to improve the strength of the grouting material, Portland cement is superfinely ground. 800-1000 mesh, the strength of the obtained grouting material is about 36-39MPa in 1 day, and 92-97MPa in 28 days. This method requires ultra-fine grinding of Portland cement, which cannot be realized by the current actual production equipment. The patent There is also no mention of the early age strength of the grout for 2-4 hours

Chinese Patent Publication No. CN101921086A discloses a cement ultra-high-strength non-shrinkage grouting material. Ordinary Portland cement is used as the cementitious material. By adding steel fibers, the 1-day strength of the grouting material reaches 70-90 MPa, and the 28-day strength reaches 120 MPa. However, due to the addition of steel fibers, the construction performance of the grouting material is greatly reduced, and it cannot enter narrow gaps for key construction, and the scope of use is greatly limited. Although the patented grouting material has very high strength, the early age is 2-4 hours. The strength of

Although this type of cementitious material can make the grouting material have good fluidity and long-term strength growth rate, due to the influence of its hydration reaction mechanism, the 1-day age strength of the cementitious material itself is very low, and it is often necessary to add a large amount of Accelerators and accelerators can significantly improve the 1-day age strength of grouting materials

And at the early age of 2-4 hours, the cementitious material based on Portland cement will not produce obvious strength at all, which is why the 2-4 hour early age strength is not mentioned in the above-mentioned existing invention patents s reason

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