Experimental Research on the Mechanical Properties and Autogenous Shrinkage of Precast Members Joint Concrete

Abstract

In the precast building structure, the joint is the key part that affects the mechanical performance of the assembly structure. By selecting coarse and fine fraction aggregate; adding high quality mineral admixture, expansive agent, and water-reducing agent; and optimizing the mixture ratio design, precast members joint concrete (PMJC) with self-compacting performance, micro-shrinkage, good volume stability, and strength matching with precast concrete is developed. In this study, the PMJC with a water-binder ratio, fly ash, ultra-fine silicon powder, sand rate, expansive agent, and water-reducing agent of 0.38, 30%, 3%, 47.7%, 8%, and 0.7%, respectively, showed a good workability which could meet the conditions of on-site construction. In addition, the strength matched the precast members, and the PMJC had certain ductility and stability, small early contraction, and met the requirements of the joint material.