Effect of the particle size of nanosilica on early age compressive strength in oil-well cement paste

Abstract

This study evaluates the early compressive strength of oil-well cement pastes containing nanosilica (NS) with different particle sizes of 10, 20 and 40 nm. The NS particles were chosen at proportions corresponding to 1, 2, 3 and 4% by weight of cement. Test results indicated that NS significantly enhanced the early compressive strength of the oil-well cement. The results also revealed that the strength enhancement was reliant on the NS particle sizes. The specimens containing NS 40 nm received greater early compressive strength and higher pozzolanic activity due to better dispersion, resulting in improved microstructures compared with specimens containing 10 and 20 nm. By fluctuating the NS dosages, the optimal replacement dosage was 3% for all particle sizes. This implies that the particle size did not affect the optimal dosage of NS, it influenced the compressive strength of cement paste. The microscopic analysis tests confirmed the findings of the compressive strength of the hardened cement paste.