低配网率纤维编织网增强混凝土轴拉力学性能
Mechanical properties of textile reinforced concrete plate at low textile ratios
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摘要: 通过单束纤维与纤维编织网增强混凝土(Textile reinforced concrete, TRC)薄板的单轴拉伸试验, 研究了纤维编织网增强混凝土这种新型材料的受力特征和影响其极限承载力的主要因素, 提出临界配网率的概念。以配网率为变化参数, 讨论了在低配网率(配网率小于1%)时材料的力学性能。当配网率大于临界配网率时, 纤维编织网增强混凝土薄板的极限承载力大于其开裂荷载, 加载过程中没有承载力突降; 随着配网率增加, 纤维的利用率随着配网率增加呈线性降低, 即纤维丝的强度并不能完全发挥。低配网率时, 随着配网率增加, 薄板的裂缝间距减小, 裂缝宽度下降。根据混合定律和ACK模型把TRC薄板的拉伸应力-应变曲线简化成三线型模型, 从宏观上提出了考虑配网率影响的极限承载力计算公式。Abstract: Uniaxial tensile experiments of textile reinforced concrete (TRC) plates and the results were detailed presented in this paper. Then the mechanical properties of textile reinforced concrete and its main influence factors on ultimate loading capacity were studied. And the concept of critical textile ratio was proposed. The mechanical properties of textile reinforced concrete plate were discussed at low textile ratios. When textile ratio was larger than the critical textile ratio, the ultimate bearing capacity exceeds the cracking load, and there was no sudden drop during the loading process. With the increase of textile ratio, the efficiency of fibers decreases in a linear way. And strength of fibers was not fully utilized. Moreover, the crack form was also investigated on different textile ratios. With the increase of textile ratio, cracking space reduces and cracking width decreases as well. Finally, according to the mixture law and ACK model, the stress-strain curve of TRC plates is simplified as a trilinear model. The calculation formula was proposed taking the textile ratio into consideration to forecast the ultimate bearing capacity of TRC plates.