纤维增强自密实轻骨料混凝土抗冻性能试验研究

Study on frost resistance of self compacting lightweight aggregate concrete with sisal fiber and polypropylene fiber

将长度均为10 mm,体积掺量为0.8 kg/m^(3)的聚丙烯纤维、体积掺量为2.0 kg/m^(3)的剑麻纤维分别掺加到强度等级为C40的自密实轻骨料混凝土(SCLC)中进行抗冻融循环试验,测试其抗压强度损失率和质量损失率.采用线性回归的方法,研究建立了3种SCLC试块不同冻融循环条件下抗压强度线性回归预测模型.与空白样对比,250次冻融循环试验后,剑麻纤维SCLC和聚丙烯纤维SCLC的质量损失率分别降低了2.12%、2.58%,抗压强度损失率分别降低了3.10%、4.30%.试验数据表明,在不同冻融循环次数下,两种不同纤维制备的SCLC的抗冻性均得到了显著提高,其中掺加聚丙烯纤维的SCLC改善效果要优于掺加剑麻纤维的SCLC.

Polypropylene fiber and sisal fiber with centent of 0.8 kg/m^(3)or 2.0 kg/m^(3)and a length of 10 mm were respectively added to self compacting lightweight aggregate concrete with strength grade C40 for the freeze-thaw cycle experiment to test the compressive strength loss rate and mass loss rate.Compared with the blank sample,the respective mass loss rate of sisal fiber SCLC and polypropylene fiber SCLC are reduced by 2.12%and 2.58%after 250 freeze-thaw cycles,and the respective strength loss rate is reduced by 3.10%and 4.30%.The experimental data show that under different freeze-thaw cycles,the frost resistance of SCLC prepared by two different fibers is significantly improved,and the improvement effect of SCLC with polypropylene fiber is better than that with sisal fiber.The linear regression model of compressive strength of three kinds of SCLC specimens under different freeze-thaw cycles was established by using linear regression method.