Microscopic mechanism research on airport pavement ultra-high-early strength concrete patching material

摘要

This article deals with the microstructure and mechanism of action of ultra-high-early strength concrete patching material through the three modern testing means: XRD, DTA and SEM. The results show that a large quantity of Aft and AFM are generated in the initial stage of the reaction in the patching material and hinge with each other to form an initial skeleton, so there is a high early strength in the macro performance. Meanwhile, there exists a significant reduction in the number of Ca(OH)_2 crystals which is detrimental to the structure, and a growing number of CSH gel are generated and uniformly filled in the initial skeleton, resulting in the formation of a dense structure. Furthermore, the addition of mineral admixtures improves the interface structure of the concrete, thus making the late strength of the concrete stable.