▁and ▁volume ▁expansion ▁of ▁the ▁pl astic , ▁the ▁temperature ▁is ▁held ▁at ▁this ▁level ▁until ▁the ▁concrete ▁reaches ▁the ▁desired ▁strength . ▁After ▁cur ing , ▁the ▁subsequent ▁lower ▁temper atures ▁cause ▁the ▁pl astic ▁to ▁contract , ▁and ▁a ▁gap ▁remains ▁at ▁the ▁interface ▁between ▁the ▁pl astic ▁and ▁concrete . ▁▁ ▁Pl astic ▁spac ers ▁are ▁also ▁subject ▁to ▁cor ros ion ▁when ▁they ▁come ▁into ▁contact ▁with ▁ch lor ides ▁and ▁chemical s , ▁where ▁concrete ▁has ▁a ▁much ▁higher ▁resistance . ▁ ▁Con crete ▁spac ers ▁and ▁bar ▁supports ▁▁ ▁Con crete ▁spac ers ▁and ▁bar ▁supports ▁are ▁made ▁of ▁the ▁same ▁material ▁as ▁the ▁pou red ▁concrete , ▁so ▁thermal ▁expansion ▁and ▁contra ction ▁are ▁equal . ▁And ▁because ▁they ▁are ▁the ▁same ▁material , ▁the ▁concrete ▁and ▁spac ers ▁will ▁bond . ▁No ▁g aps ! ▁▁ ▁Con crete ▁spac ers ▁and ▁bar ▁supports ▁help ▁maintain ▁material ▁integrity ▁and ▁uniform ity ▁of ▁the ▁concrete , ▁and ▁provide ▁a ▁cover ▁over ▁the ▁rein for cement ▁that ▁protect s ▁against ▁cor ros ion . ▁ ▁Con crete ▁spac ers ▁with ▁a ▁pl astic ▁clip ▁or ▁other ▁fixing ▁mechanism ▁▁ ▁What ▁about ▁concrete ▁spac ers ▁with ▁a ▁pl astic ▁clip ▁or ▁fixing ▁mechanism ? ▁Does ▁the ▁pl astic ▁clip ▁or ▁fixing ▁mechanism ▁in ▁the ▁concrete ▁spac er ▁have ▁a ▁negative ▁effect ▁on ▁material ▁integrity ? ▁Does ▁it ▁weak en ▁the ▁cor ros ion ▁protect ive ▁cover ▁over ▁the ▁rein for cement ? ▁The ▁answer ▁is ▁no ! ▁▁ ▁The