关键词: 超高性能混凝土(UHPC);减水剂;自密实

Abstract: Self-compacting ultra high performance concrete ( UHPC ) was produced based on the optimized design ofits particle skeleton and superplasticizer , and its properties were characterized . Firstly, the matrix of three different powders was determined by the optimized particle packing design . The effects of superplasticizer on the fluidity , strength and the hydration process of matrix were analyzed . Then, based on the obtained experimental results , one groups of matrix was selected to produce self-compacting UHPC combined with the relatively low dosages of superplasticizer , and its workability and mechanical properties were evaluated .The results indicat that a self-compacting UHPC can be produced by cement/fly ash matrix with 2.3％(23 kg/m3) superplasticizer.The strain rate of the produced self-compacting UHPC is 2.5‰, and its toughness index I5 , I10 and I20 are 7.1, 15.6, 30.8 respectively, which meet the mechanical requirements of UHPC .

Key words: ultra high performance concrete (UHPC);superplasticizer;self-compacting