PRELIMINARY STUDY ON CONCRETE WITH POLYSTYRENE COARSE AGGREGATE A. Mohd Mustafa Al Bakri 1 , G. Che Mohd Ruzaidi 1 , M.N. Norazian 2 , & H. Kamarudin 1 , 1 School Of Material Engineering & 2 School Of Environmental Engineering, Universiti Malaysia Perlis, P.O Box 77, d/a Pejabat Pos Besar, 01007 Kangar, Perlis. Polymer recycling has received a great deal of attention in this recent year. Presently, small percentage of polymer wastes in Malaysia has been under going the recycling process. This recycling process has typically been through reprocessing of the waste material into other polymeric items, or energy recovery from complete combustion. Development of concrete with non-conventional aggregate such as polymer waste (especially polystyrene), ceramic waste or any wastes were used to get comparable properties of the conventional concrete and economical aspect. This paper describes experimental study on replacing coarse in conventional concrete with polystyrene waste aggregate to produce a lightweight material. Mixture proportions were varied to investigate the effects of water-cement ratio and polystyrene waste aggregates content to obtain the best result. The properties of the aggregates were also compared. Experimental results indicate that the polystyrene aggregates can be successfully used to produce a lightweight material. The results also indicate that the workability of polystyrene waste aggregates concrete is good and the strength characteristics are comparable to those of the conventional concrete. Keyword: Polystyrene Waste Aggregate; Conventional Concrete; Compressive Strength INTRODUCTION Polystyrene wastes are becoming a major environmental concern, due to its large production quantities and its non-biodegradable nature. Provided that the high molecular-weight material can be broken down into useful low molecular-weight hydrocarbons, polystyrene wastes can be viewed as a highly valuable feedstock [1]. The possible effects of recycled aggregate upon concrete properties such as workability, strength and durability have been discussed in several paper [1–3]. Plastic wastes represent 11.1% from all municipal solid waste generated each year in the US (2001 US EPA Characterization of Municipal Solid Waste). This number does not include the majority of post-industrial plastic waste, which is accounted separately. Most of the plastic wastes goes to landfill, as its economic use is hindered by two integrated factors. First, plastic waste is comprised of a large number of different resins, and each type has had to be handled separately or sorted until now. Handling and sorting are expensive, and cause plastic waste to be less attractive as a feedstock for manufacturing. Second, products manufactured from wastes plastics have been commodity items so cost of production must be kept low. In Malaysia especially in Perlis, for landfill such as Kuala Perlis Landfill, 1/3 of the municipal solid waste is the polystyrene foam waste. Polymer recycling has received a great deal of attention in recent years. This has typically been through reprocessing of the waste material into other polymeric items, or energy recovery from complete combustion. However, polymer reprocessing is limited in the number of reprocessing cycles, since contamination and thermal degradation results from the steps of melting and reshaping [2]. Developments of concrete with non-conventional aggregates such as polystyrene foam waste were used in concrete to improve the properties of the concrete and save cost. The