REUSING WASTE MATERIALS AS CONCRETE CONSTITUENTS FOR SINGAPORE �S HIGH-RISE DEVELOPMENTS : A STUDY OF SCRAP TYRES AND RECYCLED PLASTICS

Abstract

Concrete has been well used all over the world for the construction of buildings. By looking at volume alone, concrete is considered the world’s most important construction material. It is the second material mostly used in the construction industry. It is also common to see high rise developments in Singapore, made out of concrete. Since its invention, concrete and its properties have been changed and altered to suit specific needs. With the rising environmental concern, energy consumption, and the need to reduce waste materials, there is an urgent need to address the way how the current material (concrete) is being produced, used and constructed.

In this dissertation, two new advances in concrete technology that make use of waste materials and its feasibility in Singapore are being studied. These two concretes, which consist of recycled tyre and plastic aggregates, are called rubcrete and plascrete respectively. Rubcrete and plascrete can be used as concrete fillers for both structural and non-structural applications, such as precast components, partition and external walls and longer span floor slabs. The densities of these concretes were calculated and proved to be lighter in weight than normal concrete with natural aggregates. This makes for easier construction and transportation to site, among the many other benefits. Calculation of the amount of waste materials needed for the construction of a typical high-rise building construction was done. It was roughly estimated that 40 number of 12 storey buildings can be constructed per year based on the amount of waste generated locally. This shows that the use of rubcrete and plascrete proved to be feasible in Singapore. Moreover, these new advances in concrete help to minimize biodegradable waste, reduce reliance on concrete’s virgin aggregates and promote a more environmentally-friendly construction.