▁pl astic ▁clip ▁or ▁fixing ▁mechanism ▁is ▁h ing ed ▁from ▁the ▁top ▁of ▁the ▁spac er ▁and ▁does ▁not ▁come ▁into ▁contact ▁with ▁the ▁so ff it ▁of ▁the ▁concrete . ▁The ▁pl astic ▁clip ▁or ▁fixing ▁mechanism ▁is ▁embedded ▁only ▁ 5   mm ▁into ▁the ▁spac er , ▁which ▁maintain s ▁the ▁material ▁integrity ▁at ▁the ▁product ' s ▁surface . ▁The ▁pl astic ▁in ▁the ▁clip ▁or ▁fixing ▁mechanism ▁is ▁used ▁only ▁for ▁easily ▁att aching ▁to ▁and ▁holding ▁the ▁rein for cement , ▁leaving ▁the ▁concrete ▁part ▁to ▁do ▁the ▁work ▁of ▁the ▁spac er . ▁ ▁Econom ics ▁▁ ▁Bear ▁in ▁mind ▁that ▁not ▁only ▁do ▁pl astic ▁spac ers ▁offer ▁no ▁compatibility ▁with ▁the ▁materials ▁used ▁in ▁civil ▁engineering ▁structures , ▁but ▁can ▁hold ▁only ▁a ▁fraction ▁of ▁the ▁weight ▁a ▁concrete ▁spac er ▁can , ▁therefore ▁you ▁must ▁use ▁more ▁pl astic ▁spac ers ▁to ▁cover ▁the ▁same ▁amount ▁of ▁rein for cement ▁( the ▁ratio ▁is ▁normally ▁ 1 ▁to ▁ 2 , ▁but ▁will ▁increase ▁if ▁the ▁weight ▁of ▁the ▁re bar ▁structure ▁is ▁increased , ▁r ati os ▁of ▁up ▁to ▁ 3 ▁to ▁ 1 ▁have ▁been ▁observed ), ▁so ▁there ▁may ▁be ▁no ▁real ▁value ▁either ▁economic ▁or ▁technical ▁added ▁when ▁pl astic ▁spac ers ▁are ▁used . ▁ ▁References ▁ ▁Category : Build ing ▁engineering ▁Category : Build ing ▁materials ▁Category : Re in for ced ▁concrete <0x0A> </s> ▁Ces are ▁G ale otti ▁( 5 ▁June ▁ 1