Properties of Methacrylic Water-Soluable Polymer as a Superplasticicer for Ultra High-Strength Concrete

A technology to impart high fluidity to concrete with an extremely low W/C range of about 0.2 is required, in order to place ultra high-strength concrete with a compressive strength of over 100 MPa. For this purpose, the authors have developed a methacrylic water-soluable polymer as a superplasticizer (SSP) that imparts adequate workability and excellent cement dispersing capability to concrete mixtures with low W/C. Also, the high cement content of ultra high-strength concrete containing normal portland cement leads of high concrete temperature due to heat of hydration, posing problems of thermal cracking and low long-term strength. This study used a low-heat, belite-rich portland cement recently developed in Japan, together with powder silica fume to produce ultra high-strength concrete containing the SSP with a low water-binder ratio of approximately 0.2. As a result, the belite-rich portland cement was found to reduce the adiabatic temperature rise without causing set retardation when compared with normal portland cement. In addition, the concrete showed high fluidity as well as a high long-term compressive strength of over 150 MPa. These results suggest that the SSP is highly compatible with low-heat cement and is very effective in producing high-performance concrete when used in combination with this type of binder.