The effects of temperature,fiber type,basalt fiber content,mixed basalt fiber(BF)and cellulose fiber(CF)on the mechanical properties of concrete were studied by compressive strength and splitting tensile strength tests after high temperature.The results show that basalt fiber or cellulose fiber can improve the compressive and splitting tensile strength of concrete after high temperature,and the improvement effect of basalt fiber is better than that of cellulose fiber at the same volume content.At each test temperature,the compressive and splitting tensile strength increased with the increase of basalt fiber volume fraction.The optimum volume fraction of single basalt fiber was 0.20％,the increase rate of compressive strength was from 13.1％to 32.6％,and the increase rate of splitting tensile strength was from 28.0％to 62.4％.The compressive strength and splitting tensile strength of concrete can be improved by mixing appropriate amount of BF and CF at each test temperatures,which have positive mixing effect.When the volume fraction of basalt fiber was 0.15％and the volume fraction of cellulose fiber was 0.10％,the compressive strength and splitting tensile strength of B2C1 group were the highest.Compared with ordinary concrete,the increase rate of compressive strength was from 14.8％to 36.2％,and the increase rate of splitting tensile strength was from 31.6％to 75.3％.The positive and negative hybrid effect of basalt fiber and cellulose fiber was analyzed by introducing synergistic effect coefficient,and the calculation model of compressive strength and splitting tensile strength of fiber reinforced concrete after high temperature was established,which can be used for structural design and post-disaster performance evaluation of fiber reinforced concrete.
关键词
高温/混杂纤维混凝土/玄武岩纤维/纤维素纤维/力学性能
Key words
high temperature/hybrid fiber concrete/basalt fiber/cellulose fiber/mechanical properties
维普
万方数据