纳米粒子和钢纤维增强混凝土抗碳化和抗渗性能

Carbonation Resistance and Anti-permeability of Nano-particles and Steel Fiber Reinforced Concrete

为探明纳米粒子和钢纤维对混凝土抗碳化性能和抗渗性的影响,采用混凝土渗水高度试验法测得了抗渗试件在压力水作用下的渗水高度,并对试件进行了3,7,14 d,28 d碳化试验,测得了试件相应龄期的碳化深度。纳米粒子的掺量分别为1%,3%,5%,7%,9%,钢纤维体积掺量分别为0.5%,1%,1.5%,2%,2.5%。试验结果表明:纳米SiO_2在一定掺量范围内可以提高混凝土的抗碳化性能,但过量就会对混凝土抗碳化性能产生不利影响;随着纳米SiO_2掺量的增加,混凝土的抗渗透性能先增强后降低;掺入适量钢纤维可以提高纳米混凝土的抗碳化性能,但过量的钢纤维会降低纳米混凝土的抗碳化性能;掺入钢纤维会降低纳米混凝土的抗渗性能。

The water penetration heights of the specimens were measured using water penetration height test method,and the carbonation depths of the specimens for different curing periods（1 day,7days,14 days,28 days） were measured by carbonization tests to explore the effect of nano-particles and steel fibers on the carbonation resistance and anti-permeability of concrete.Five different contents of nano-particles（1%,3%,5%,7%,9%） and five different volume dosages of steel fiber（0.5%,1%,1.5%,2%,2.5%） were adopted.The results show that the carbonation resistance of concrete can be improved by the addition of nano-SiO_2 with the appropriate content.However,the excess of nano-particles will have adverse impacts on the carbonation resistance of concrete.With the increase of nano-SiO_2,the anti-permeability of concrete is enhanced first and then decreased.Addition of proper amount of steel fibers can improve the carbonization resistance of concrete containing nano-particles,however excessive steel fibers will reduce the carbonization resistance of the specimens.Besides,the addition of steel fiber will reduce the anti-permeability of concrete containing nano-particles.