The effect of a radiation-initiated polyester on the physicomechanical properties of a sand/clay-polyester composite has been investigated. The unsaturated polyester resins containing various styrene contents were used at different sand/clay composites from 10 to 70 wt % with respect to the weight of sand and clay together; polymerization was conducted using ␥-irradiation at 50 kGy. Also, different particle sizes of clay (namely 1.25-0.80, 0.80 -0.50, and Ͻ0.50) were used. The compressive strength, apparent porosity, and water absorption-in addition to infrared spectroscopy of the composite samples-were studied. Results indicate that the compressive strength decreases with an increase in sand/clay, as well as the styrene content in the unsaturated polyester resin, whereas the apparent porosity and water absorption of the composite samples increase. Infrared spectra showed the appearance of new bands, which indicated a chemical reaction between polyester and clay constituents.

The effect of impregnation time on the physico-chemical and mechanical properties of polyeste~cement mortar composite has been investigated. The samples were soaked in unsaturated polyester resin containing 40% styrene monomer at impregnation times ranging from 1 15 hours and then exposed to 50 kGy of ~/-irradiation. The effects on polymer loading, compressive strength, apparent porosity, and water absorption in addition to IR spectra and TGA of the samples were studied. It was found that, the polymer loading and compressive strength increase with the increased of soaking time up to 4 hours and there is no significant improvement of the polymer loading and strength. Whereas, the apparent porosity and water absorption behave in an opposite direction. These are attributed to the presence of polymer in the pores of the samples. IR spectra showed that, new bands appeared as result of the reaction between polyester and set cement. TGA showed that, the polyester cement composite has higher thermal stability as a compared to irradiated polyester.

The influence of methyl metharcylate and gamma exposure dose on the physico-chemical and mechanical properties of polymer-alite composite have been investigated. The hardened alite samples were impregnated with a methyl methacrylate monomer and then subjected to Y irradiation doses from 10-50 KGy. The effect of polymer loading (%), compressive strength, bulk density and the microstructure (scanning electron microscopy SEM), in addition IR spectra were studied. The results indicate that, polymer loading, compressive strength and bulk density increase with increasing absorbed dose. This is attributed to the deposition of the polymer in the pores of the samples. SEM showed the voids between the particles in the samples before the impregnation, whereas, the formation of new products in the pores appeared after impregnation.