Hydration, phase and microstructure development of Ultra-High Performance Concrete
Summary: This paper gives an overview of the microstructural results regarding hydration, phase and microstructure development of Ultra-High Performance Concretes which differ in their binder composition. A matter of particular interest was the way in which ground granulated blast furnace slag influences the hydration process and the microstructure development. The results show that the hydration of Ultra-High Performance Concretes containing ground granulated blast furnace slag is significantly retarded although reduced superplasticizer content was used. Due to an optimised grain granulometry, high content of fine particles as well as low w/c ratio and an extremely strong interlocking of the C-S-H phases, a considerable microstructure densification is visible.
During the last decades Ultra-High Performance Concrete has gained more interest in research and concrete application due to the development of highly effective concrete additives. In the middle of the nineties Cheyrezy et al. [1] established the term “Reactive Powder Concrete” (RPC) for high performance concretes with a high content of particles ≤ 125 µm (cement, quartz powder, pozzolanic additives) and low water to cement ratio (w/c). Over the years the English term “Ultra-High Performance Concrete” (UHPC) was established. An updated overview of capabilities and applications...