聚丙烯腈纤维混凝土的低温性能

Properties of Polyacrylonitrile Fiber Reinforced Concrete at Low Temperatures

研究了低温环境下 (气温变化为 - 15～ 5℃ )聚丙烯腈 (PAN)纤维对混凝土力学性能增长趋势的影响 ;探讨了快速冻融试验条件下 (- 17.5～ 7.5℃ )PAN纤维混凝土的抗冻融耐久性 .通过扫描电子显微镜 (SEM)观察发现PAN纤维在混凝土中分散性较好、纤维间距小、纤维和混凝土界面结合状况良好 .研究结果表明 ,掺入PAN纤维增加了混凝土的含气量 ,提高了混凝土的抗拉极限应变、抗弯韧性和断裂能 ,因而有利于混凝土低温环境下的强度增长和提高了混凝土的抗冻融耐久性 .

Effect of polyacrylonitrile (PAN) fiber on the development of mechanical properties of concrete at low temperatures (air temperature ranges from -15～5 ℃) was studied,and the durability of freezing-thawing resistance of PAN fiber reinforced concrete was also researched under fast freezing-thawing-cycle condition (temperature ranges from -17.5～7.5 ℃).By scan electronic microscope (SEM) photography,the PAN fibers were found to be of well-distributed with short spaces,and to be firm interface combined with concrete.Results of the investigation indicated that adding PAN fibers into concrete leads to high air content,improves tensile strain limit,flexural toughness and fracture energy,which are beneficial to strength development and durability improvement of concrete at low temperatures.