水泥基秸秆纤维复合材料力学性能研究

Study on Mechanical Properties of Cement-based Straw Fiber Composites Materials

通过对秸秆纤维进行碱浸渍预处理,并与普通硅酸盐水泥拌和制备轻质复合材料,研究了秸秆纤维长度、水灰比和秸秆纤维掺量对水泥基秸秆纤维复合材料性能的影响。结果表明,用4%浓度的NaOH溶液浸渍12 h预处理的2~5 mm秸秆纤维掺量5%、体系水灰比0.60时,水泥基秸秆复合材料干表观密度为1 320 kg/m^3,吸水率为8.7%,28 d抗压强度为3.1 Mpa。对秸秆的碱浸渍处理可以解决水泥凝结问题,在水泥基材料中掺入适量的预处理短秸秆纤维,可以制备出具有实用价值的轻质复合材料。

One of the effective ways to increase utilization of straw is to use it in fabricating building materials.In the preparation of cement-based materials,the problem of the influence of straw on cement setting should be solved first.The straw fiber was pretreated by alkalizing and mixed with ordinary portland cement to prepare lightweight composite samples.The effects of straw fiber length,water-cement ratio and straw fiber content on the properties of cement-based straw fiber composites were studied.The results indicate that when water absorption is 8.7%,W/C is 0.60,and the content of 2~5 mm straw fiber pretreated with 4% NaOH solution for 12 h is 5%,a lightweight composite with dry apparent density 1 320 kg/m^3 is prepared,and its 28 d compressive strength is 3.1 Mpa.The pretreatment of straw fiber by alkalizing with NaOH solution in 4% concentration is feasible to solve setting problem of cement paste caused by alkaline digestion of straw.So,the useful lightweight composite can be fabricated with cement and suitable amount of short fiber pretreated by alkalizing.