玄武岩纤维编织网增强混凝土高温后力学性能及损伤机理

通过制备普通及高铝水泥玄武岩纤维编织网增强混凝土(TRC)薄板,采用四点弯曲试验、XRD衍射和扫描电镜微观分析,探究玄武岩TRC在高温作用后的力学性能和损伤机理。研究结果表明:玄武岩纤维织物能有效减小TRC薄板在高温下的变形,抑制裂纹的扩张,且高铝水泥玄武岩TRC高温后的变形及质量损失均小于普通水泥TRC;玄武岩TRC的抗弯承载力随着温度的升高近似呈线性降低,降低的主要原因是高温下混凝土基体损伤、纤维编织网高温劣化及纤维与基体的黏结劣化三者的共同作用;扫描电镜分析可知,高铝酸盐水泥基TRC比普通硅酸盐水泥基TRC更致密,对高温有更强的抵抗作用。本研究可为TRC在高温环境中的设计和应用提供借鉴。

Mechanical Properties and Damage Mechanism of Basalt Textile Reinforced Concrete after High Temperature

Basalt textile reinforced concrete (TRC) was prepared with Portland and high aluminate cement respectively. The damage mechanism of TRC after high temperature was investigated by four-point bending test, XRD diffraction and SEM. The results show that basalt fiber textile can effectively reduce the deformation of TRC sheets and inhibit the expansion of cracks at high temperature. The deformation and mass loss of high aluminate cement-based TRC are smaller than those of Portland cement-based TRC after high temperature. The flexural bearing capacity of basalt TRC decreases approximately linearly with the increase of temperature, and the decrease is mainly due to the combined effect of three factors: the damage of concrete matrix at high temperature, the high temperature deterioration of fiber woven fabric, the deterioration of bond between fiber and TRC matrix. SEM analysis shows that high aluminate cement-based TRC is denser and more resistant to high temperature than Portland cement-based TRC. This study provides a reference for the design and application of TRC in high temperature environment.