24 сентября, 2015 
Malyar About 30% of all polymers produced each year are used in the civil engineering and building industries(23). Nevertheless, structural plastics such as fibre reinforced composites have so far received little attention by civil and structural engineers, despite some of their obvious advantages such as lightness, handleability and corrosion resistance. This may be due to reservations on credibility grounds or fire resistance properties, as well as to uncertainty on how to design structures with them. Whilst their mechanical properties are in fact fairly well understood, there are a number of problems concerned with making joints with and between these materials. Currently mechanical fasteners such as bolts are utilised but adhesives, either alone or in addition, can offer significant advantages.
In building and construction, pipes probably represent the largest volume of plastics usage whilst engineered plastics have found their way into structural frames, platforms and walkways, and for use as post-tensioning tendons on some concrete bridges in Germany (at Dusseldorf and Berlin)(23, 24). For very aggressive environments, pultruded fibreglass reinforcing bars are beginning to be accepted in concrete constructions. In the future, bundles of pultruded fibres may be formed into lighter weight cables for suspension bridges, to enable very long spans to be accommodated. At a smaller scale it may be possible to exploit filament wound hollow sections in trusses and space frame structures. Current research effort is being directed towards the problems of joining, by bonding, tubular composite members for use in plane and space grid frames(23).
Опубликовано в рубрике 