大温差条件下碳纤维混凝土无约束变形试验

Experimental Research on Unconstrained Deformation of Carbon Fiber Concrete in Large Temperature Difference Condition

为了研究碳纤维、聚酯纤维对混凝土在自由条件下的约束作用,通过设计对碳纤维混凝土、聚酯纤维混凝土和素混凝土加热放热试验,比较掺入不同纤维体积分数的纤维混凝土在大温差条件下无约束自由变形的差异,并用温度线膨胀系数表达。对试验数据进行分析,得到体积分数为1%的碳纤维混凝土比素混凝土抗自由变形能力提高了38.8%,在本试验的各种体积分数中效果最好。结果表明碳纤维与混凝土,虽然热力学性能不同,但是二者结合之后碳纤维因其高弹性模量的特性,反而可以更好地抑制混凝土自由变形。试验效果也表明,随着施工工艺的完善,碳纤维体积分数可能会超过1%,碳纤维对混凝土性能的提升仍然有很大的帮助。

To study the constraint of carbon fiber and polyester fiber to concrete in free conditions, the research designs the test of the heating and releasing heat of carbon fiber reinforced concrete, polyester fiber reinforced concrete and plain concrete, compares the difference of unconstrained deformation of fiber reinforced concrete incorporated with different volume ratios of fiber in large tem- peratures difference condition, and expresses the difference with temperature coefficient of linear expansion. Analysis of experimental data shows that the anti-free-deformation capacity of carbon fiber reinforces concrete with volume fraction of 1% is optimal among those with various dosages of carbon fiber,and larger than that of plain concrete by 38.8%. The results show that the combination of carbon fiber and concrete can inhibit the free deformation of concrete effectively due to the high elastic modulus properties of carbon fiber,though the inherent properties of carbon fiber and concrete are different. Test resuhs also show that, with the improvement of construction technique,the volume fraction of carbon fiber in concrete may exceed 1% , and be possible to enhance the performance of concrete markedly.