It is well known that when pores of hardened cement are filled with a suitable polymer, desirable properties are greatly enhanced. With microwave induced polymerization, significant increases in compressive strength are observed.
Mortar samples with a sand cement ratio of 2.5 and water cement ratios, 0.3, 0.4, and 0.5, were molded and hardened. After sufficient hydration, they were evacuated, filled with MMA and pressurized. The samples were then processed in a dynamic multimode applicator. Temperature was monitored and they were processed until the temperature exceeded 85°C.
The principal result is the increase in compressive strength as compared to an untreated sample. For a W/C=0.5, and a sample hydrated for one day, the strength increased by a factor of6.0. In addition, the highly porous 1 day polymerized samples exhibited significantly greater strength than 28 day unpolymerized material.