Table 21. Preformed materials for waterstops, gaskets, and sealing purposes. 1 



COMPOSITION AND TYPE 



PROPERTIES SIGNIFICANT 

 TO APPLICATION 



AVAILABLE IN 



(1) Butyl • Conventional 

 Rubber Cured 



High resistance to water, vapour 

 and weathering. Low permanent 

 set and modulus of elasticity form- 

 ulations possible, giving high co- 

 hesion and recovery. Tough. 

 Colour - Black, can be painted. 



Beads, Rods, tubes, flat 

 sheets, tapes and purpose- 

 made shapes. 



Waterstops, Combined crack 

 inducer and seal. Pressure 

 sensitive dust and water seal- 

 ing tapes for glazing and 

 curtain walls. 



(2) Butyl - Raw, Polymer 



modified with resins and 

 plasticisers 



High resistance to water, vapour 

 and weathering. Good adhesion to 

 metals, glass, plastics. Moldable 

 into place but resists displacement, 

 tough and cohesive. Colour - 

 Black, can be painted. 



Beads, tapes, gaskets, 

 grommets. 



Glazing seals, lap seams in 

 metal cladding. Curtain wall 

 panels. 



(3) Neoprene - Conventional 

 Rubber cured 



High resistance to oil, water, 

 vapour and weathering. Low 

 permanent set. Colour - 

 basically black but other surface 

 colours can be incorporated. 



Beads, rods, tubes, flat- 

 sheets, tapes, purpose-made 

 shapes. Either solid or open 

 or closed cell sponges. 



Waterstops, Glazing seals. 

 Insulation and Isolation of 

 service lines. 



Tension-Compression seals. 

 Compression Seals, Gaskets. 



PVC 



Polyvinylchloride 

 Thermoplastic, 

 Extrusions or Moldings 



High water, vapour, but only 

 moderate chemical resistance. 

 Low permanent set and modulus of 

 elasticity formulations possible, 

 giving high cohesion and recovery. 

 Tough. Can be softened by heating 

 for splicing. Colour - Pigmented 

 black, brown, green, etc. 



Beads, rods, tubes, flat 

 sheets, tapes, gaskets, 

 purpose-made shapes 



Waterstops, Gaskets, Com- 

 bined crack inducer and seal 



(5) Polyisobutylene 

 Non curing 



High water, vapour resistance. 

 High flexibility at low temperature 

 Flows under pressure, surface 

 pressure sensitive, high adhesion. 

 Sometimes used with butyl com- 

 pounds to control degree of cure. 

 Colour - Black, grey, white 



Beads, tapes, grommets, 

 gaskets. 



Gaskets, Glazing Seals, 

 Curtain wall panels. 

 Acoustical partitions. 



(6)a SBR (Styrene 



Butadiene Rubber) 



(6)b NBR (Nitrile 



Butadiene Rubber) 

 Polyisoprene - poly- 

 diene - Conventional 

 Rubber cure 



High water resistance, NBR has 

 high oil resistance. 



Beads, rods, flat sheets 

 tapes, gaskets, grommets, 

 purpose-made shapes. 

 Either solid or cellular 

 sponges. 



Waterstops, Gaskets for pipes 

 Insulation and Isolation of 

 Service Lines 



(7) Polyurethane, Foam 



impregnated with poly- 

 butylene 



Low recovery at low temperature, 

 can be installed in damp joints. 

 Colour - Black, grey 



Rods flat sheets (strips) 

 open cell sponges 



Gaskets, Compression Seals. 



(8) Natural Rubber - cured 

 (vulcanized) 



High water resistance but deter- 

 iorates when exposed to air and 

 sun. Low resistance to oils and 

 solvents. Now largely superseded 

 by synthetic materials. Colour - 

 black 



Purpose-made shapes. 



Waterstops, Gasket for pipes 



Metals 



(a) Copper 



(b) Steel (stainless) 



(c) Lead 



(d) Bronze 



For waterstops: 



(a) Ductile and Flexible, but work 

 hardens under flexing and 

 fracturess. 



(b) Rigid must be V or U corr- 

 gated to accommodate any 

 movement and anchored. 



(c) Deforms readily but inelastic 



to deformation under movement. 



Flat and preshaped strips. 

 Lead also molten or yarn. 



(a) (b) Waterstops 



(c) Protection for joint edges 

 in floor. 



(d) Panel dividers in floor 

 toppings 



(10) Rubber Asphalts 



Natural Rubber 8, Butyl 1 , or 

 Neoprene 3 digested in asphalt. 

 High viscosity, some elasticity. 

 Moldable into place. 



Beads, rods, flatsheets 



(strips) 



(IIG IIIK), Gasket for 



As alternative to hot or cold 

 applied Rubber asphalts 

 (IIG UK), Gasket for 

 pipes. 



ACI, 1979, Part 3. 



128 



