The Preparation And Curing System Research Of Self-compacting Reactive Powder Concrete

Based on maximum desity principle,raw materials of RPC’s preparation were selected.The raw materials were:42.5ordinary potland cement、 high quality silica fume、 ultra-fine fly ash of600mesh、 quartz sand of40-70mesh、 ViscoCrete3301R polycarboxylate superplasticizer.Based on basic mix proportion,the effect of proportion ratio and the content of fly ash on RPC’s mechanical properties and workability were studied furtherly.And then determined the optimal mix of RPC.The mix was:cement:silica fume: quartz powder: quartz sand=1:0.25:0.37:1.1, water-cement ratio=0.18,2.0%superplasticizer. Under this mix,when the water-ratio was changed to0.22,RPC’s slump flow reached148mm,and after3days90℃hot water curing,its compressive strength reached143.8MPa;when it was changed to0.23, the fresh RPC paste’s slump flow reached263mm,with no segregation and no bleeding,after3days90℃hot water curing,its7day compressive strength reached103.68MPa.Then the effect of steel fiber content by volume and the curing system especially dry heat curing on Self-Compacting RPC’mechanical properties and workability were studied.The results show that:(1)With the increase of steel fiber content,the liquidity of fresh self-compacting RPC paste decreased;the optimal content of steel fiber by volume was2.0%;(2)Under the standard curing conditions,self-compacting RPC had a rapid development in the first7days;Hot water curing and dry heat curing both benefitted to increase the compressive strength of self-compacting RPC;The optimal time of90℃hot water curing was3days;Dry heat curing which curing temperature was below200℃,was against the improvement of self-compacting RPC strength.