水致弱化影响下粉煤灰泡沫混凝土充填体性能试验研究

Experimental Study on Foamed Concrete Block Filler under the Influence of Moisture Content

以普通硅酸盐水泥、发泡剂、粉煤灰和外加剂为原料,制备采空区充填材料。通过试验研究,在不同含水率影响下,充填体的强度特性、应力-应变特性和变形特性。研究结果表明:自由水对充填体力学性能弱化较为明显。具体表现为:随含水率增加,制备的充填体试件抗压强度、抗剪强度递减,前期递减幅度较大,后期较小;充填体峰值强度、峰后残余强度以及延性均随含水率增加而递减;随含水率的增加,弹性模量降低幅度较大,泊松比变化幅度较小,剪切模量和体弹性模量均减小,水弱化影响下充填体会产生进一步压缩。

Using ordinary portland cement,foaming agent,fly ash,admixture as raw material to make paste filling material.Studying filling strength characteristic,stress-strain relationship and deformation characteristic under the influence of different moisture content by laboratory test.The results show that the weakening of the filling is obvious in free water.Specific performance is that with the increase of moisture content,the compressive strength and shear strength of filling decrease,early decrease range is larger,latter is smaller;peak strength of filling,post peak residual strength and ductility decrease with the increase of moisture content;With the increase of moisture content,the elastic modulus decreases faster,the Poisson＇s ratio changes smaller,other deformation parameters such as shear modulus,elastic modulus both decrease.The filling further compresses in moisture content.