温度对C50纤维混凝土力学性能的影响

结合武汉市某工程大体积混凝土实测温度,试验研究了高温高碱环境对纤维自身力学性能的影响,及不同养护温度下混凝土的力学性能发展趋势.试验结果表明:聚丙烯纤维在10%浓度的NaOH溶液中浸泡24 h且经历室温—65℃—室温循环,纤维自身力学性能下降约10%;处理后的纤维掺入混凝土中对标准养护的试块强度无不良影响;不同养护温度下纤维混凝土力学性能发展趋势差异明显,65℃养护1 d龄期的轴心抗压强度、弹性模量、劈裂抗拉强度可达标准养护28 d龄期相应参数的97%,74%,74%,4 d龄期轴心抗压强度、劈裂抗拉强度有一定增长趋势.因此,大体积混凝土实体结构强度评定需考虑水化温度作用的影响.

Effect of Temperature on Mechanical Properties of C50 Fiber Concrete

Through measured temperature of one project in Wuhan City,the effect of high temperature and high alkali environment on mechanical properties of fiber and development tendency of concrete mechanical properties under different curing temperature was studied.The results showed that mechanicals of fiber decrease by 10% after polypropylene fibers immersed in 10% NaOH solution for 24 h cycling between 65 ℃ and 25 ℃;fibers treated which were incorporated into concrete had no bad effect on strength of the specimen;there was a big difference on development tendency of fiber concrete mechanical properties under different curing temperature.1 d axial compressive strength,elastic modulus and splitting tensile strength could respectively reached 97%,74% and 74% of 28 d corresponding parameters.Axial compressive strength increased slowly and splitting tensile strength increased a little after 4 d.So the effect of hydration temperature should be taken into consideration when assessing entity structure strength of the high-volume concrete.