Ultra-High-Performance Concrete: Development of On-Site Fresh Mix Rheology Test Methods

Abstract

Experimental investigations were conducted on the challenges that may be encountered in the industrial-scale production of ultra-high-performance concrete (UHPC). The rheological attributes of fresh UHPC mixtures were investigated, and a convenient set of tests were developed for field evaluation of the UHPC rheological attributes. These tests would allow for adjustment of the water content of the delivered UHPC to provide adequate workability characteristics, considering that the distinctly low water content of UHPC mixtures make them more prone to the adverse effects of the lack of control on the actual water content of concrete materials produced at industrial scale. The effects of water content on the fresh mix rheology and hardened UHPC compressive strength were evaluated. Distinctions were made between the fresh mix rheology of the UHPC paste versus normal Portland cement paste.