PAN基碳纤维复合混凝土的制备及氯离子渗透性的影响

Preparation of PAN based carbon fiber composite concrete and influence of chloride ion permeability

以聚丙烯腈(PAN)基碳纤维为无机填料,制备了PAN基碳纤维复合混凝土,研究了PAN基碳纤维掺量对混凝土力学性能、耐磨性能、抗冻性能等的影响。结果表明,PAN基碳纤维的添加加速了水化反应的进行,减少了混凝土结构中的孔隙数量,提高了混凝土的密实度。复合混凝土的抗压强度和抗折强度随PAN基碳纤维掺杂量的增大而先增大后减小,养护28 d,当PAN基碳纤维的掺杂量为0.8%(质量分数)时,抗压强度和抗折强度达到最大值,分别为50.73和5.58 MPa,这是由于PAN基碳纤维的添加使砂浆与集料之间的结合强度增加所致。养护28 d,当PAN基碳纤维的掺杂量为0.8%(质量分数)时,复合混凝土的单位面积磨损量最小为0.95 kg/m^(2),单位面积磨损量降低率最大为55.81%,冻融循环100次时质量损失率最低为1.14%,相对动弹性模量最高达95.03%,复合混凝土的氯离子扩散系数最低为8.1×10^(-8)cm/s,具有优异的抗冻性能和抗氯离子侵蚀能力。

PAN based carbon fiber composite concrete was prepared with polyacrylonitrile(PAN)based carbon fiber as inorganic filler.The effects of the content of PAN based carbon fiber on the mechanical properties,wear resistance and frost resistance of concrete were studied.The results showed that the addition of PAN based carbon fiber accelerated the hydration reaction,reduced the number of pores in the concrete structure,and improved the compactness of concrete.The compressive strength and flexural strength of composite concrete increased first and then decreased with the increase of PAN based carbon fiber doping.After 28 d of curing,when the doping amount of PAN based carbon fiber was 0.8 wt%,the compressive strength and flexural strength reached the maximum,which were 50.73 and 5.58 MPa respectively.This was because the addition of PAN based carbon fiber increased the bonding strength between mortar and aggregate.After 28 d of curing,when the doping amount of PAN based carbon fiber was 0.8 wt%,the minimum abrasion loss per unit area of composite concrete was 0.95 kg/m^(2),the maximum reduction rate of abrasion loss per unit area was 55.81%,and the minimum mass loss rate was 1.14%,the maximum relative dynamic modulus of elasticity was 95.03%,the minimum chloride diffusion coefficient of composite concrete is 8.1×10^(-8) cm/s.It had excellent frost resistance and chlorine ion resistance.