Improving quality of high performance concrete by cavitation treatment of the raw materials

Abstract

The packing of fine aggregate affects the properties of HPC. The denser is fine aggregate packing the better are the workability, compressive strength and watertightness, and with that the frost and chemical resistances under sufficient paste content upplementary cementing materials such as silica fume has predominantly used for HPC due to it improves the packing of the concrete mix and activates the pozzolanic reaction. But agglomerates can be formed in this fine aggregate mix and therefore the packing of the mix is not improved, chemical reaction is hindered and the use of this aggregate may worsen the concrete properties instead of improving them. The effect of cavitation treatment on silica fume and cement is investigated in this work. Due to cavitation treatment, the agglomerate of silica fume and cement collapses into nano- and micro-particles and uniforms dispersion of small dispersed particles in liquid medium. Granulometric composition of silica fume slurry before and after cavitation treatment was determined. High performance concrete mixes with designed packing including micro- and nano-size fillers were elaborated. Fresh and hardened concrete were tested and such properties as cone flow, watertightness, water absorption and compressive strength were defined for control and experimental mixes. The influence of cavitation treatment of small dispersed raw materials on the compressive strength properties of produced concrete has been evaluated.