稻草纤维增强泡沫混凝土物理力学性能试验研究

Experimental study on the physical and mechanical properties of straw fiber reinforced foam concrete

为了研究稻草纤维增强泡沫混凝土的性能,以普通硅酸盐水泥为主要胶凝材料,硅灰、偏高岭土和粉煤灰为辅助胶凝材料,稻草纤维为增强材料,采用物理发泡法制备纤维增强泡沫混凝土;通过全因子试验,研究在不同水胶比和发泡剂掺量下,稻草纤维掺量对泡沫混凝土的密度、吸水率、抗压强度、抗折强度、劈裂抗拉强度和抗冻性能的影响。结果表明:对于不同水胶比和发泡剂掺量,泡沫混凝土的密度、抗压强度和劈裂抗拉强度均随纤维掺量的增加呈现出先增加后降低的变化规律;抗压强度随密度增加呈幂函数增加关系;劈裂抗拉强度随抗压强度的增加呈指数函数增加关系;当水胶比为0.45时,抗折强度随纤维掺量的增加先增加后降低,当水胶比为0.50时,抗折强度随纤维掺量的增加而增加;纤维的掺入增大了泡沫混凝土的泡孔尺寸和吸水率,降低了其抗冻性能。

In order to study the properties of straw fiber reinforced foam concrete,fiber-reinforced foam concrete was prepared by the physical foaming method with ordinary Portland cement as the main cementitious material,silica fume,metakaolin and fly ash as the supplementary cementitious materials,and rice straw fiber as reinforcement material.The effects of straw fiber content on the density,water absorption,compressive strength,flexural strength,splitting tensile strength and frost resistance of foam concrete were investigated by full factorial tests at different water-to-binder ratios and foaming agent dosages.The results showed that the density,compressive strength and splitting tensile strength of straw fiber reinforced foam concrete increased first and then decreased with the increase of fiber content for different water-to-binder ratios and foaming agent dosages.The compressive strength increased with density as a power function.The splitting tensile strength increased exponentially with the increase of compressive strength.When the water-to-binder ratio was 0.45,the flexural strength increased first and then decreased with the increase of fiber content.When the water-to-binder ratio was 0.50,the flexural strength increased with the increase of fiber content.The incorporation of fiber increased the pore size and water absorption rate of foam concrete,and reduced its frost resistance.