哑铃型钢纤维粉煤灰混凝土的弯曲疲劳特性

混凝土的弯曲疲劳性能是钢纤维混凝土的主要力学性能.用4点加载方法重点研究了全掺钢纤维混凝土梁和底层撒布较长钢纤维的聚丙烯腈纤维混凝土梁的弯曲疲劳性能.研究证明:底层撒布较长钢纤维的聚丙烯腈纤维混凝土梁的弯曲疲劳强度比素混凝土提高15.7％;当应力水平为0.90时,全掺钢纤维(体积分数为1.0％)混凝土梁弯曲疲劳寿命是素混凝土22.47倍,底层撒布较长钢纤维的聚丙烯腈纤维混凝土梁的弯曲疲劳寿命是素混凝土的29.O1倍.即底层撒布较长钢纤维的聚丙烯腈纤维混凝土梁的弯曲疲劳性能比单独撒布一层钢纤维或单独采用聚丙烯腈纤维来增强混凝土效果更加显著.对于道路及机场跑道采用这一结构形式比较理想.表7,参9.

Flexural fatigue behavior of end bigger steel fiber reinforced fly ash concrete

Fatigue strength of concrete is an important mechanics behavior for fiber reinforced concrete structures. The third-point loading method was used to determine the fatigue properties of steel fiber reinforced concrete beams and polyacrylonitrile fiber reinforced concrete beams with bottom layer steel fiber. The test results show that, the flexural fatigue strength of polyacrylonitrile fiber reinforced concrete beams with bottom layer steel fiber is larger than the plain concrete 15.7% ; when the steel fiber concentrations used were 1.0% by volume and the fatigue stress ratio is 0.9, the flexural fatigue life of steel fiber reinforced concrete is 22.47 times of control concrete, the fatigue cycles of polyacrylonitrile fiber reinforced concrete is 22 times of the plain concrete, the polyacrylonitrile fiber reinforced concrete beam with the bottom layer steel fiber is 29.01 times of the control concrete. The polyacrylonitrile fiber reinforced concrete beams with bottom layer steel fiber pavement is an new type of material and new type of pavement structure, which is more effect to improve the fatigue strength than alone used the bottom layer steel fiber or polyacrylonitrile fiber to reinforced concrete. 7tab,9refs.