材料期刊网

为研究不同应变率和温度下耐碱玻璃织物增强水泥基复合材料的弯曲力学行为,采用美特斯(MTS)万能试验机和INSTRON落锤冲击系统对其试样分别进行室温(25℃)下准静态三点弯曲(应变率为3.33×10-5 s-1)和不同应变率(4、8、12、16和18 s-1)及温度(-50、0、25、50和100℃)下的动态三点弯曲试验,静态和动态三点弯曲试验采用一套弯曲夹具.同时考虑了增强织物层数对其弯曲力学性能的影响.试验结果表明:室温下,随应变率的增加,弯曲强度提高,弯曲峰值应变和韧性先减小后增大,弯曲模量先增大后减小;应变率为12 s-1时,随着温度的升高,弯曲强度、弯曲模量和韧性整体上减小,弯曲峰值应变变化不明显;纤维织物为六层时,对混凝土的增韧效果较明显.应变率、温度和织物层数均能对试样的弯曲性能产生较大影响.

In order to investigate the strain rate and temperature effect on the flexural mechanical properties of alkali-resistant glass fabric reinforced cement matrix (FRCM) composite, the FRCM composite specimens were tested under quasi-static (3.33×10-5 s-1) loading in 3-point bending set-up using a MTS load frame at room temperature (25℃), and under dynamic loading in the same 3-point bending set-up at different strain rates (4, 8, 12, 16 and 18 s-1) and distinct temperatures (-50, 0, 25, 50 and 100℃) utilizing an INSTRON drop-tower impact system.The same fixture was used in quasi-static and dynamic flexural tests.The effect of the number of reinforcing fabric layers on their flexural mechanical properties was also taken into consideration.The experimental results show that, at room temperature, flexural strength increases with increasing strain rate, but flexural ultimate strain and toughness firstly decrease and then increase with increasing strain rate, and flexural modulus firstly increases and then decreases with increasing strain rate.At the same flexural strain rate of 12 s-1, flexural strength, flexural modulus and toughness decrease with increasing temperature, and ultimate strain does not change significantly.When alkali-resistant glass fabric with six layers is used in the composite specimens, the reinforcing effect is more significant.The strain rate, temperature and the number of reinforcing fabric layers can significantly affect the flexural performance of specimens.