A self-leveling low-shrinkage high-strength mortar

Abstract

The invention discloses self-leveling mortar with low shrinkage and high strength. The mortar is prepared from a cementitious material, fine aggregate, a fiber, an additive and water, wherein the cementitious material is prepared from Portland cement, sulphoaluminate cement and a mineral admixture and accounts for 28%-36% of the total mass; the fine aggregate contains light sand and river sand and accounts for 54%-60% of the total mass, and the mass ratio of the fine aggregate to the cementitious material is 1.5-2.2; the fiber is a steel fiber, accounting for 0.1%-0.5% of the total volume; the additive is a water-reducing agent, accounting for 0.8%-2.5% of the mass of the cementitious material; the water and the cementitious material are in a mass ratio of 0.26-0.35, and the water accounts for 8 %-10% of the total mass. According to the mortar, the problems about inherent high shrinkage and high fluidity of the high-strength mortar are mainly solved, self-leveling can be realized, the shrinkage index of the mortar can meet the shrinkage requirement of the concrete with equal strength and low shrinkage, the 28d compressive strength exceeds 60 MPa, and requirements of severe service environments such as carbonization, freeze-thawing and ion erosion can also be met; the mortar has the characteristics of low shrinkage, high fluidity, high strength and full durability.

Description

technical field [0001] The invention belongs to the field of building materials, in particular to a self-leveling low-shrinkage high-strength mortar. Background technique [0002] The structure used in modern engineering is becoming more and more complex, and the environment is becoming more and more diverse, and the requirements for various properties of mortar are gradually increasing. Traditional mortar is generally composed of Portland cement, yellow sand and water. Water is only used to improve fluidity, and the water-binder ratio is not used to control the strength. Modern mortar technology has developed, and the types of commercially available mortar have increased, but most of the mortar is still ordinary masonry mortar and thermal insulation mortar, and the cementitious material has been changed from simple ordinary Portland cement to Portland cement. Ash, the water-binder ratio is reduced from about 1.0 to about 0.6. At the same time, a small amount of water reduc...

AI Technical Summary

Problems solved by technology

Modern mortar technology has developed, and the types of commercially available mortar have increased, but most of the mortar is still ordinary masonry mortar and thermal insulation mortar, and the cementitious material has been changed from simple ordinary Portland cement to Portland cement. Ash, the water-binder ratio is reduced from about 1.0 to about 0.6. At the same time, a small amount of water reducer and thickener are added to ensure the water retention and fluidity of the mortar, but its shrinkage value is very large, and the shrinkage value of 28d can reach more than 1mm. The use of high-strength mortar will further increase the shrinkage of the mortar. Similarly, the mortar that improves the fluidity of the mortar to a self-leveling state generally has a high content of cementitious materials, so its shrinkage will be further increased, and it is difficult to have both high strength and large fluidity. Low shrinkage, good durability