Mix design and engineering properties of ultra high performance self compacting concrete

Abstract

The mechanical properties (compressive strength and flexural strength) were investigated under different curing conditions (standard and steam curing). Silica fumes have characteristics that make them necessary in cement composites with ultra strength properties. The search for substitute products thus appears important if the use of ultra high performance concrete (UHPC) is to become more widespread in the concrete industry. Possibilities of getting ultra high performance self compacting concrete (UHPSCC) with materials available in Serbia, based on experimental work are discussed in this paper. Four series of samples were made with different types of fine reactive additives (silica fume in referent concrete was replaced with metakaolin at 20% and 40% and with fine fly ash at 20%.). The produced mixes had self compacted consistency. The compressive strength varied between 145 and 180 MPa for the steam cered specimens and between 180 and 205 MPa for the ones that had not been heat treated. Furthermore, this paper presents SEM micrographs of C-S-H phase formed after steam curing and autoclaving.