Investigations on the preparation and mechanical properties of the nano-alumina reinforced cement composite

In order to investigate the effect of nano-alumina on the elastic modulus and compressive strength of cement composite, cylindrical specimens (Φ20 × 40 mm) with different volume fractions of nano-alumina at different curing days (3 days, 7 days, 28 days) were cast and tested. Based on experiment, the compressive strength and elastic modulus of mortars were all increased by incorporating nano-alumina into matrix. When the fraction of nano-alumina was 5%, the elastic modulus of composites increased by 143% at 28 days; when the fraction of nano-alumina was 7%, the compressive strength of composites increased by 30% at 7 days. The compactness of interfacial transition zone increased and porosity of cement decreased by incorporating nano-alumina into mortars, and as a result, the elastic modulus and compressive strength of mortar with nano-alumina increased.