钢纤维TRC薄板的常温及高温后弯曲力学性能
BENDING BEHAVIOR OF TRC THIN-PLATES WITH SHORT STEEL FIBERS AT ROOM TEMPERATURE AND AFTER HIGH TEMPERATURE
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摘要: 该文将短切钢纤维掺入纤维编织网增强混凝土(TRC)薄板中,通过四点弯曲试验,比较了短切钢纤维的长径比和掺量对TRC薄板常温下及高温后弯曲性能的影响。高温处理采用可实现程序控温的高温炉,按ISO834国际标准升温曲线进行加热,高温处理时间为0.5 h或1.0 h。结果表明,外掺钢纤维有助于提高TRC薄板常温下的承载力和初裂后刚度,钢纤维长径比对TRC薄板的承载力和变形能力影响不大,钢纤维掺量为1.0%的TRC薄板承载力提高了61%。随着高温作用时间变长,TRC薄板承载力大幅下降,连续贯穿裂缝数目大量减少,1.0 h高温后几乎丧失多缝开裂的破坏特征。无论在常温下或高温处理后,钢纤维体积掺量1.0%的TRC薄板均具有相对较好的力学性能。Abstract: This paper focuses on the textile reinforced concrete(TRC) thin-plates with the addition of short steel fibers. The influence of the length-diamond ratio and the volume content of short steel fiber on the bearing capacity of TRC thin-plates are investigated by means of four-point bending tests. ISO-834 International Standard Fire Curve is controlled by programmed temperature furnace, and the heating time is 0.5h or 1.0h respectively. The experimental results show that the addition of short steel fibers can improve the bending capacity and stiffness after the cracking of the TRC thin-plates. Length-diamond ratio of short steel fibers has little influence on the bearing capacity and deformability of the TRC thin-plates. The bending capacity of specimens with 1.0% steel fiber addition has increased by 61%. With longer heating temperature time, the bearing capacity of the TRC thin-plates decreases gradually, and the number of continuous crack reduces greatly. All the specimens almost lost the damage characteristics of multiple cracking after heated by 1.0h. Whether exposed to room temperature or high temperature, the TRC thin-plates with 1.0% steel fibers addition shows a certain residual mechanical property.