钢纤维混凝土抗冻性及损伤模型研究

Study on Frost Resistance and Damage Model of Steel Fiber Reinforced Concrete

选取钢纤维掺量为0%、1.5%,基体混凝土强度等级为C30、C40的混凝土试件进行冻融试验与抗压强度试验,研究其质量损失率变化规律及抗压强度衰减规律。以得到的抗压强度数据为损伤变量建立三种不同的函数模型。结果表明:冻融循环200次后,2组钢纤维混凝土试件组较素混凝土试件组的质量损失率减少了0.69%和1.09%,抗压强度损失率减少了3.9%和4.0%,说明钢纤维的掺入减小了混凝土强度的衰减以及冻融损伤。对三种函数所拟合的损伤模型相关系数进行比较,基于二项式函数所拟合的损伤模型精度最高,相关系数均超过0.95。

Concrete specimens with 0%and 1.5%steel fiber content and C30 and C40 concrete strength grade were selected for freeze thaw test and compressive strength test to study the change law of mass loss rate and compressive strength attenuation law.Three different functional models were established using the compressive strength data as damage variables.The results show that after 200 freezing thawing cycles,the mass loss rate of SFRC specimens decreases by 0.69%and 1.09%,and the compressive strength loss rate decreases by 3.9%and 4.0%compared with plain concrete specimens,indicating that the addition of steel fiber reduces the strength attenuation and freezing-thawing damage of concrete.The correlation coefficients of the damage model fitted by the three functions were compared.The damage model fitted by the binomial function had the highest accuracy,and the correlation coefficients were all over 0.95.