Waterstop

A waterstop is an element of a concrete structure, intended to prevent the passages of fluids (such as water) when embedded in and running continuously through concrete joints. Waterstops are grouped in two distinct categories. Waterstops for joints without any movement of the adjoint concrete sections (construction cold joints) and waterstops for joints with movement of the adjoint concrete sections (dilation joints).

Waterstops are being manufactured from a variety of materials depending on the functionality and their intended use.

The most common types are:

waterstops made from extruded plastics such as flexible polyvinyl chloride PVC, polyethylene (PE) or thermoplastic vulcanizate rubber (TPV); formed metal such as stainless steel, copper, or carbon steel - with or without polymeric coatings; extruded thermosets such as natural rubber, styrene-butadiene rubber, or neoprene rubber.

Hydrophobic Polymer waterstops such as PVC, PE, TPV, or rubber are supplied to the construction site in coils (usually 25 m long), and are generally anywhere from 120 mm to 320 mm wide in a variety of profiles that are designed to simultaneously provide an interlock with the concrete they are installed in and to provide for a limited amount of movement within the joint. PVC, PE and TPV waterstops are made continuous for the length of the concrete joint by heat welding, using simple thermoplastic welding equipment. PE and TPV waterstops are generally installed in joints of secondary containment structures to prevent the passage of hazardous fluids other than water such as fuel oils, acids, or process chemicals. The German national standards DIN 18541 and DIN 7865 regulate dimensions and material properties of polymeric waterstops.