关键词: 自密实混凝土;应力应变全曲线;强度;断裂能;CRSIII型板式无砟轨道

Abstract: In order to understand the mechanical properties of SCC applied in CRTS III type slab ballastless track filling layer , serials experiments were carried out to prepare self-compacting concrete (SCC) applied for filling layer by use of expansive agent and viscosity enhanced agent .Fracture characteristics and stress-strain behavior of SCC with different mixtures and normal concrete ( NC) were studied by load-displacement curves and stress-strain curves under uniaxial compression .The results indicate that the fracture mode of SCC is different from that of NC .Compared to NC with same strength grade, the peak strain of SCC is larger than NC and the declined curve decreases rapidly .The incorporation of sulphoaluminate expansive agent greatly decreases the fracture toughness property of SCC and increases its brittleness .The fracture characteristics of SCC with expansive agent and viscosity enhanced agent is a little bit lower than that of NC , which the reduction rate of fracture energy and ductile index is no more than 10％.

Key words: self-compacting concrete;stress-strain curve;strength;fracture toughness property;CRTS III type slab ballastless track