纤维编织网增强混凝土的拉伸力学模型

Tensile mechanical model of textile reinforced concrete

通过单束纤维与纤维编织网增强混凝土(TRC)薄板的单轴拉伸试验,研究了环氧树脂浸渍后纤维束的应力-应变关系。试验结果发现,即使经环氧树脂浸渍,也不能完全发挥碳纤维束的抗拉强度;单轴拉伸碳纤维束获得的应力-应变曲线几乎是完全线性的,在达到其极限强度80%左右出现一定的非线性特征。假定细粒混凝土开裂后只有纤维编织网承担荷载,从而由TRC薄板试件单轴拉伸的荷载-变形关系获得的碳纤维束的应力-应变关系可合理简化为双线性的形式,并针对本文中研究的纤维编织网给出了其相应控制参数点的取值。基于受弯构件计算理论,采用本文纤维束拉伸模型得到的两种系列受弯构件的计算值与试验值吻合较好。

Uniaxial tensile experiments of yarns and textile reinforced concrete （TRC） plates were carried out to study the stress-strain relationship of the epoxy resin-impregnated textile. The experimental results show that even if the carbon fiber yarn is impregnated with the epoxy resin, its tensile strength is not fully utilized. Besides some nonlinear characteristic of its stress-strain curve after the tensile stress of the yarn reaching about 80% of its ultimate strength, its stress-strain relationship is almost linear when the carbon fiber yarn is tensioned alone. Assume that only the textile bears the load after fine grained concrete cracking, and thus the stress-strain relationship of the carbon fiber yarn, which was obtained from the curves of the load-deformation with uniaxial tensile test of TRC-thin plate specimens, could be reasonably simplified as the bilinear form, and the corresponding control parameters of the textile in this study were presented. Based on the flexural calculation theory and using the tensile model of the yarn proposed in this paper, the obtained calculated values of two series of flexural members coincide well with their experimental values.