Effect of Duyen Hai 3 thermal power plant fly ash on the compressive strength development of cement mortar over time

Tóm tắt

DOI: https://doi.org/10.66195/mtu.2025.15.105

This study investigates the effect of fly ash (FA) from Duyen Hai 3 Thermal Power Plant on the compressive strength development of cement mortar over time. Mortar mixes were prepared with FA replacing cement at 0%, 5%, 10%, 15%, and 20% by weight. Compressive strength was evaluated at 3, 7, 28, and 56 days of curing. At 3 and 7 days, the mix containing 5% FA achieved the highest strength, while replacement levels of ≥10% led to reduced early strength. At 28 and 56 days, the 10% FA mix attained the highest strength, surpassing the control mix, attributed to the effective pozzolanic reaction. The 15% replacement level showed strength comparable to the control, whereas 20% replacement resulted in significant strength reduction at all ages. Duyen Hai 3 FA, characterized by high reactive oxide content, appropriate fineness, and low loss on ignition, contributed to the formation of additional C-S-H gel and pore filling in the mortar matrix.