comparative evaluation of poly urethane and poly vinyl chloride in lining concrete sewer pipes for preventing biological corrosion

corrosion makes huge economic and ecologic damage all over the world. biologic corrosion of sewer pipes is considered as a serious limitation in economic perspectives. to prevent biologic corrosive damage, lining techniques can be applied by materials and aggregate resistant to attack bacterially in sewer pipes. the role of bacteria is that they convert sulfur compounds into sulfuric acid which causes highly corrosion. in this study, some concrete samples were lined using polymeric materials called poly urethane (pu) and poly vinyl chloride (pvc) and the role of these linings was compared in terms of improving durability and resistance of concrete samples in acidic environment. the experimental results indicated that, after a 3-month period, in comparison with pvc, poly urethane showed better durability and resistance in acidic aggressive environment. furthermore, having made strong bonds with concrete surface, pu lining minimized the penetration of acidic solution [generated by sewage fermentation in sewer pipes] toward the concrete body.