补偿收缩钢渣混凝土应力-应变关系试验

Stress-Strain Relationship of Shrinkage Compensating Steel-Slag Concrete

以废弃钢渣为粗骨料制备补偿收缩钢渣混凝土试件,并对其进行抗压强度、弹性模量及泊松比试验,分析了水灰比对补偿收缩钢渣混凝土试件破坏形态、抗压强度、变形及应力-应变关系的影响.结果表明:补偿收缩钢渣混凝土试件破坏形态与普通混凝土相似,但前者出现裂缝时间较晚,裂缝发展速度较快,峰值应变较小;随着水灰比的减小,补偿收缩钢渣混凝土试件的抗压强度逐渐增大,弹性模量先增后减;补偿收缩钢渣混凝土试件的变形、应变和弹性模量均小于普通混凝土,泊松比是普通混凝土的2~3倍.由于补偿收缩钢渣混凝土内部含有的缺陷和空隙较少,其应力-应变关系曲线的线性阶段较长,曲线反弯点不明显.基于补偿收缩钢渣混凝土试验结果,提出了补偿收缩钢渣混凝土峰值应力、峰值应变、弹性模量和泊松比的计算方法,建立了补偿收缩钢渣混凝土应力-应变关系模型,此模型计算结果与试验结果吻合较好.

Shrinkage compensating concrete specimens were prepared by adding waste steel-slag.Experiment on compressive strength,elastic modulus and Poisson＇s ratios of concrete prism were carried out to analyze the effect of water-cement ratio on the failure mode,compressive strength,deformation and stressstrain relationship.Test results show that the failure mode of shrinkage compensating steel-slag concrete is similar to that of ordinary concrete,the cracking time of shrinkage compensating steel-slag concrete is later,the crack growth rate is faster,and the peak strain is smaller.With the decrement of water-cement ratio,the bearing capacity of the specimens increases gradually,and the elastic modulus increases at first and then decreases.The deformation,strain and elastic modulus of the specimens are all less than that of ordinary concrete,and Poisson＇s ratio is 2-3times of ordinary concrete.Due to the less internal defects and voids of shrinkage compensating steel slag concrete,the linear phase of the stress-strain curve is longer,and the bend point of the curve is not obvious.Based on the experimental study of shrinkage compensating steel slag concrete,the calculating formula of the peak stress,peak strain,elastic modulus and Poisson＇s ratio of the shrinkage compensating steel-slag concrete is proposed,and then the stress-strain model is established.The calculating results of the model are in good agreement with the experimental results.