Research on the Application of Expansive Agent in C60 Self-Compacting Concrete

It analyzed the performance, mechanical properties, volume stability, microstructure of hydration cementitious material of C60 self-compacting expansion concrete, which dependent on CSA to expansive ettringite source for the expansion. Results suggest that on the same curing conditions, C60 self-compacting concrete with the water-cement ratio of 0.32 admixture CSA expansive agent can effectively control the shrinkage of concrete, so that it is slightly inflated. The dosage of CSA expansive is higher, early strength of C60 self-compacting concrete is lower and its late strength declines small. It is affected little for the slump and extended degree of concrete under the superplasticizer by the expansive agent. SEM results show that CSA expansion agent can improve the pore structure of hydrated cement paste system with low water-binder ratio. The gel phase after hardening has good compactness and ettringite needlelike crystals mostly distribute at each interface layer.