Waterstop
Encyclopedia
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 frequently manufactured 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; or 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 50 lineal feet long), and are generally anywhere from 4 inches to 12 inches 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. Thermoset rubbers and metallic waterstops are more difficult to fabricate to continuous lengths and are specified far less frequently by architects and engineers.
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.
Hydrophilic or "water-loving" waterstops are strips of rubber, modified with a hydrophilic agent (such as bentonite) so they swell in the presence of moisture to effectively seal concrete construction joints. Hydrophilic strip applied waterstops should not be used in contraction or construction joints per the instructions of most commercial manufacturers. Hydrophilic waterstops can only be effective if they are allowed to swell; therefore, a moisture source must be present to activate the hydrophilic agent. Initial leaking is possible until the waterstop expands to seal the joint.
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
structure, intended to prevent the passages of fluids (such as water) when embedded in and running continuously through concrete joints. Waterstops are frequently manufactured from extruded plastics such as flexible polyvinyl chloride PVC
Polyvinyl chloride
Polyvinyl chloride, commonly abbreviated PVC, is a thermoplastic polymer. It is a vinyl polymer constructed of repeating vinyl groups having one hydrogen replaced by chloride. Polyvinyl chloride is the third most widely produced plastic, after polyethylene and polypropylene. PVC is widely used in...
, polyethylene
Polyethylene
Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...
(PE) or thermoplastic
Thermoplastic
Thermoplastic, also known as a thermosoftening plastic, is a polymer that turns to a liquid when heated and freezes to a very glassy state when cooled sufficiently...
vulcanizate rubber (TPV); formed metal such as stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
, copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, or carbon steel; or extruded thermosets such as natural rubber, styrene-butadiene
Styrene-butadiene
Styrene-Butadiene or Styrene-Butadiene-Rubber is a synthetic rubber copolymer consisting of styrene and butadiene. It has good abrasion resistance and good aging stability when protected by additives, and is widely used in car tires, where it may be blended with natural rubber...
rubber, or neoprene
Neoprene
Neoprene or polychloroprene is a family of synthetic rubbers that are produced by polymerization of chloroprene. Neoprene in general has good chemical stability, and maintains flexibility over a wide temperature range...
rubber.
Hydrophobic Polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
waterstops such as PVC, PE, TPV, or rubber are supplied to the construction site in coils (usually 50 lineal feet long), and are generally anywhere from 4 inches to 12 inches 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. Thermoset rubbers and metallic waterstops are more difficult to fabricate to continuous lengths and are specified far less frequently by architects and engineers.
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.
Hydrophilic or "water-loving" waterstops are strips of rubber, modified with a hydrophilic agent (such as bentonite) so they swell in the presence of moisture to effectively seal concrete construction joints. Hydrophilic strip applied waterstops should not be used in contraction or construction joints per the instructions of most commercial manufacturers. Hydrophilic waterstops can only be effective if they are allowed to swell; therefore, a moisture source must be present to activate the hydrophilic agent. Initial leaking is possible until the waterstop expands to seal the joint.