建筑增强用聚丙烯腈纤维的耐海水腐蚀性研究

模拟混凝土应用的海洋环境,在常温(25℃)、氯化物浓度为5610 mg/L的海水中对建筑增强用聚丙烯腈(PAN)纤维进行浸泡处理,研究建筑增强用PAN纤维的耐海水腐蚀性,并与聚对苯二甲酸乙二醇酯(PET)增强纤维和聚丙烯(PP)增强纤维进行对比。结果表明:海水浸泡50 d后,建筑增强用PAN纤维的主要吸收特征峰无明显变化,且无新的吸收特征峰出现,纤维超分子结构变化较小,晶区取向度基本保持不变,结晶度略有增加;海水浸泡50 d后,建筑增强用PAN纤维的拉伸强度为1261 MPa、降幅0.63%,初始模量为18.6 GPa、增幅8.14%,其拉伸强度与PET增强纤维相当、约为PP增强纤维的1.8倍,初始模量约是PET增强纤维的1.4倍、PP增强纤维的3.2倍;建筑增强用PAN纤维、PET增强纤维、PP增强纤维的拉伸强度耐蚀系数分别为99.4%,99.2%,100.0%,建筑增强用PAN纤维的耐海水腐蚀性介于PP增强纤维和PET增强纤维之间,但其在海水中环境中具有优异的模量保持优势,可以更好地提高混凝土在海水环境中的耐受力。

Study on seawater corrosion resistance of polyacrylonitrile fiber for building reinforcement

A polyacrylonitrile(PAN)fiber for building reinforcement was exposed to seawater soaking in 5610 mg/L chloride concentration at room temperature(25℃)for 50 d based on the simulation of marine environment of concrete application.The seawater corrosion resistance of PAN fiber for building reinforcement was studied and compared with that of polyethylene terephthalate(PET)reinforced fiber and polypropylene(PP)reinforced fiber.The results showed that the main absorption characteristic peaks of PAN fiber for building reinforcement had no obvious change,no new absorption characteristic peak appeared,the supermolecular structure of PAN fiber changed little,the orientation degree of crystal region remained unchanged,and the crystallinity increased slightly after soaking in seawater for 50 d;the PAN fiber for building reinforcement had the tensile strength of 1261 MPa with a decrease of 0.63%,equal to that of PET reinforced fiber and about 1.8 times that of PP reinforced fiber,and the initial modulus of 18.6 GPa with an increase of 8.14%,about 1.4 times that of PET reinforced fiber and 3.2 times that of PP reinforced fiber;and the corrosion resistance coefficients of tensile strength of PAN,PET and PP reinforced fibers for building reinforcement were 99.4%,99.2% and 100.0%,respectively,PAN fiber for building reinforcement had the seawater corrosion resistance between those of PP and PET reinforced fibers,but possessed excellent modulus retention in seawater environment,which helped improve the resistance of concrete in seawater environment.