Material for repairing microdefects on surface of concrete

Abstract

The invention relates to a material for repairing microdefects on a surface of concrete, belonging to the technical field of concrete engineering. The material comprises the following components by mass percent: less than or equal to 90% of sulfoaluminate cement, less than or equal to 50% of superfine mineral powder, less than or equal to 50% of gypsum, less than or equal to 50% of active silica powder, and less than or equal to 20% of composite additive, wherein the specific surface area of the superfine mineral powder is 400-500m<2> / kg, the specific surface area of the active silica powder is 1500-2500m<2> / kg, the composite additive is the composite of a powdery retarder, polycarboxylate superplasticizer dry powder, a powdery early strength agent, and a powdery defoaming agent, and the water cement ratio is not less than 0.3. The material is mainly technically characterized in that the expansion rate and setting time are controlled by regulating mixing amount of the material through control of expansion. Due to the addition of superfine mineral powder and active silica powder, the surface quality and corrosion resistance of the concrete are improved; by means of the composite additive, the compactness of the surface of the concrete is improved.

Description

technical field [0001] The invention belongs to the technical field of concrete engineering, and discloses a surface micro-defect repairing material based on sulphoaluminate cement, ultrafine mineral powder, silicon powder, composite admixture and expansion regulating material as main materials, which can be used together with quartz sand . The material has the characteristics of controllable setting time, early strength, high strength, strong cohesiveness, quantitative control of expansion size and rate, strong erosion resistance, smooth and dense surface after repair. Background technique [0002] Micro-defects on the concrete surface refer to micro-cracks, micro-shedding, and micro-erosion on the surface of the concrete. Generally, the width of micro-cracks is less than 0.5mm and the depth is less than 5cm. Micro-shedding generally refers to surface sand lines and small parts falling off due to bleeding during concrete pouring, insufficient vibration, defective formwork,...

AI Technical Summary

Problems solved by technology

However, the early expansion can not play an expansion role because the repair material is in a plastic state; the middle expansion makes the structure dense and becomes a component of the strength skeleton; the later expansion makes the expansion source fill the gaps in the repair material structure, making the structure more compact; but excessive expansion will counterproductive