Hardening, microstructure, and shrinkage development of UHPC: A review

Abstract

Ultra-high performance concrete (UHPC) refers to cement-based materials exhibiting com- pressive strength higher than 120 MPa, high ductility, and excellent durability. High cracking tendency of UHPC derived from autogenous shrinkage can be a concern due to its high binder content and low water to binder ratio (w/b). This paper reviewed early hardening, microstructure, and shrinkage develop- ment of UHPC. The effect of supplementary cementitious materials (SCMs), such as silica fume (SF), ground granulated blast furnace slag (GGBS), fly ash, limestone powder, rice husk ash, and nano-mate- rials, and curing methods on hydration and microstructure was reviewed. In addition, the effect of cement, water content, aggregate, chemical admixtures, SCMs, curing methods, and fiber on the shrinkage of UHPC was summarized. Different methods to compensate and/or reduce the early-age shrinkage of UHPC were introduced.