In this study, compressive strength performance of boron active belite cement containing fly ash at the ratios of 0, 10, 20, and 30% (by weight of cement) is researched against aggressive environments; sea water, 5% sodium sulphate solution, and 5% ammonium nitrate solution in addition to tapping water. Alternative low energy cement i.e., Portland-composite cement was used and its results were compared with those of boron active belite cement. Early strength losses (reaching up to 40%) of the boron active belite cement with incorporation of fly ash up to 30% were found to be less pronounced than those (reaching up to 51%) of Portland-composite cement in tapping water. Although, the losses were highly compensated with the prolonged curing period (90 days), boron active belite cement and Portland-composite cement kept their losses up to 14% and 36%, respectively. Residual mechanical properties (reaching up to 67%) of boron active belite cement against aggressive environments were found almost similar to those of Portland-composite cement in presence of 30% fly ash. In conclusion, the study shows that belite cements with low fly ash contents can be a reasonable alternative for specific applications such as mass concrete, hot weather concreting especially in aggressive environments.