Author(s)

N. M. Elbasha

Abstract

The introduction of high strength concrete and steel reduces the size of structural members whilst having the same load carrying capacity and a resultant saving on construction time, material, labour and space. Therefore, using both high strength steel and high strength concrete in construction is very important for producing a lightweight structure. High strength concrete (HSC) and high strength steel are used together to increase a beam’s load capacity and reduce its cross section. Using these two materials to design over-reinforced beams will reduce the size, weight and costs, which is a desirable result, but because they lack ductility, the current codes of practice disallow their use. This study shows that ductility can be significantly improved by installing helical confinement in the compression zone. In the last 20 years there has been extensive research to economically utilize new components to improve the quality of HSC. HSC produces smaller but stronger structural elements with large spaces available. This proved that structures constructed with HSC are lighter and economical compared with those constructed with normal strength concrete (NSC). This study presents recent information on the benefits of HSC and also provides, in brief, experimental proof that installing a helix with a suitable pitch and diameter in the compression zone of beams significantly enhances their strength and ductility. Therefore designers could confidently use HSC and helical confinement to design long and lightweight (by reducing the beam size) reinforced concrete beams. Keywords: lightweight structures, reinforced concrete beams, high strength concrete, helical confinement.

Keywords

lightweight structures, reinforced concrete beams, high strength concrete, helical confinement.