玄武岩纤维棒聚合物混凝土的弯曲韧性

Flexural Toughness of Basalt Fiber Bar Polymer Concrete

研究了玄武岩纤维棒(BFB)的纤维增强指数I_(R)对玄武岩纤维棒聚合物混凝土(BFB-PC)韧性指标T_((2(n-1)))(n)的影响,通过分形理论探究了T_((2(n-1)))(n)与裂缝形貌的关系,并建立了弯曲韧性计算模型.结果表明:当IR=90.0时,BFB对BFB-PC的增韧效果最优,此时BFB-PC的弯曲韧性比未掺BFB时提升了8.39倍;BFB的增韧阈值为IR=37.5和IR=90.0;当IR相同时,与未掺聚合物的混凝土相比,聚灰比为0.06的BFB-PC T_((2(n-1)))(n)更高;IR越大裂缝形貌越复杂,T(2(n-1))(n)与裂缝分形维数呈二次函数关系;本文提出的弯曲韧性计算模型准确描述了BFB对PC梁的增韧作用,其试验值与理论值的相对误差小于15.00%.

The impact of the fiber reinforcement index(IR)of basalt fiber bars(BFB)on the toughness index T_(2(n-1))(n)of basalt fiber bar polymer concrete(BFB-PC)was investigated.The relationship between T_(2(n-1))(n)and crack morphology was discussed by fractal theory.A calculation model of flexural toughness was established.The results indicate that,compared to PC without BFB,when IR is 90.0,BFB has the best toughening effect on BFB-PC,and the flexural toughness of BFB-PC is increased by 8.39 times.The toughening thresholds of BFB are IR=37.5 and IR=90.0.When the IR is the same,T_(2(n-1))(n)of BFB-PC with the polymer-cement ratio of 0.06 is higher than that of concrete without polymer.The crack morphology becomes more complicated with the increases of IR,and T2(n-1)(n)has a quadratic function relationship with the fractal dimension of the crack.The model accurately expresses the toughening effect of BFB on PC beams,and the relative error between the experimental and theoretical values is less than 15.00%.