多因素影响下铣削型钢纤维混凝土劈裂抗拉强度

Splitting Tensile Strength of Mill Cut Steel Fiber Reinforced Concreteunder Multiple Influential Factors

关键词:  劈裂抗拉强度  铣削型钢纤维  粗骨料  水灰比  混凝土

Key words:  splitting tensile strength  mill cut steel fiber  coarse aggregate  water cement ratio  concrete

摘要:

通过铣削型钢纤维混凝土立方体试块劈裂抗拉试验，探讨了钢纤维体积分数（φf）、粗骨料最大粒径（dmax）和水灰比（mW/mC）等因素对铣削型钢纤维混凝土劈裂抗拉强度（fft）的影响.结果表明：铣削型钢纤维平均长度为35mm时，能够显著提高混凝土的劈裂抗拉强度，随着φf，dmax（≤20mm）增加，fft及其增益比逐渐增加；随着mW/mC增加，fft及其增益比逐渐减小；铣削型钢纤维混凝土劈裂抗拉强度与测试试块断面特性有关，在试验结果分析的基础上，建立了铣削型钢纤维混凝土劈裂抗拉强度计算模型；采用BP神经网络对铣削型钢纤维混凝土劈裂抗拉强度进行了预测.

Abstract:

Through splitting tensile strength test on the cubic specimens of mill cut steel fiber reinforced concrete(SFRC), effects of influencing factors including the fiber volume fraction(φf), the maximum coarse aggregate size(dmax) and the water cement ratio(mW/mC) upon the splitting tensile strength of mill cut SFRC(fft) were studied. The results show that steel fibers are able to improve the splitting tensile strength of concrete when the average length of steel fiber is 35mm. fft and its increment ratio tend to increase as φf or dmax(≤20mm) increases. However fft and its increment ratio tend to decrease as mW/mC increases. fft is related to the characteristics of the cross section of the specimen. Based on the experimental results, a computational model is proposed to calculate the splitting tensile strength of mill cut SFRC. The splitting tensile strength of mill cut SFRC is then predicted by means of BP neural network.