Radiation-Induced Polymer Impregnated Sawdust-Clay-Cement Composite

The preparation of a new composite material has been achieved by the impregnation of sawdust-clay-cement mixtures with unsaturated polyester resins containing styrene and in one case, methyl methacrylate (MMA) monomers, followed by exposure to Co-60 gamma radiation to induce graft copolymerisation of the polyester/monomer mixture. The most suitable impregnation time and radiation dose have been determined for two polyester compositions. The high compression strength and bending modulus show that the final material produced was comparable in mechanical properties with high strength concrete. Hydration of the sawdust-clay-cement mixture after moulding for between 1 and 28 days decreased the porosity of the composite because the hydration products were deposited within the pore-spaces. The effect on the mechanical properties of the resin content, which in turn affects the porosity, was greater than that of the hardening of the cement component after hydration.