A new elastomer for construction and building

Abstract

A new melt-processable elastomer has recently been introduced into Europe. Its unique combination of rubber-like properties and the ease with which it can be fabricated into extrusions and mouldings, using the techniques of either the rubber or the plastic industries, have already led to a number of developments of interest in construction and building. A brief review of rubber technology is followed by a description of the key properties of the new elastomer which are of interest to the construction industry. An explanation is given of some of the difficulties that can arise through the misunderstanding of the practical significance of the tests used by rubber technologists. The importance of stress relaxation measurements for the design of seals and gaskets and the desirability of simulated service tests are then discussed. An independent test programme of a window/door gasket made from the new elastomer, which was undertaken by the Norwegian Building Research Institute in the summer of 1987, is considered in detail. The results are of great practical significance because many of the tests simulate actual working conditions. The article continues by reporting comparative weather resistance tests, which show that the new elastomer is very nearly as good as chlorosulphonated polyethylene. It is also unaffected by wood preservatives and is compatible with silicone sealants. In conclusion, two interesting and unusual applications for the new elastomer are described. The first is a revoluntionary method of fixing the facade on the new “Grande Arche” in Paris, where 40, 000 small mouldings are used to overcome the stresses induced by strong gusts of wind. The second is the use of elastomeric mouldings to protect the threads in a novel range of couplers used to connect the reinforcing bars used in concrete.