ABSTRACT
Hardened ordinary Portland cement mortar pastes were prepared with different water
/ cement ratios within the range of 0.25 to 0.50 and cured for various time intervals
up 28 days. At each hydration time the hardened specimens were, then,
impregnated with different monomers; these are : castor oil (C.O), isocyanate and
methyl methacrylate (MMA). Polymerization was carried out by subjecting the
impregnated samples to different doses of γ-radiation where polyurethane (PU),
polyurethane-methyl methacrylate copolymer were formed within the pore system.
The influence of polymer impregnation of the various physico-mechanical
characteristics of the resulting composites, namely, compressive strength, of the
samples in connection with water cement ratio, radiation dose and curing period was
discussed. Scanning electron microscopy (SEM) was employed to study the
microstructural characteristics of the neat hardened OPC mortar pastes and their
polymer-impregnated composites.