Why water bars are used in casting concrete members ?

Question

Why water bars are used in casting concrete members ?

Answer 1

In water retaining structure water bar is being used to make the joint water tight. Water bar is nothing a member of rubber and the like. During casting of water retaining structure, in stages, half of the water bar is inserted in the concrete. Remaining half will be inserted in the next phase of casting. So a water proofing membren continiously exists between the two stages of concrete and make the joint water tight. As it is well known that the joint of the concrete layer is the weakest leak proof zone in the R.C.C member.