Roller Compacted Concrete （RCC） incorporating natural pozzolan was used in Bashan Dam project in Pakistan. To rapidly estimate the 1 a compressive strength of the RCC， the apparent activation energy of the composite cementitious material made from natural pozzolan and cement was tested at different temperatures. An attempt was made to use the Freiesleben-Hansen-Pedersen （FHP） model to calculate the equivalent standard curing age（equivalent age） under different accelerated curing regimes. The results indicate that the apparent activation energy of the composite cementitious material at 70-90 ℃ is difficult to be measured experimentally. However， based on the temperature dependence of the apparent activation energy， it can be calculated through univariate linear regression of the apparent activation energy at 5-60 ℃， leading to an improved FHP model. Based on field test results at the project site， compared to the FHP model， the deviation rate of the equivalent age calculated at 90 ℃ using the improved FHP model from the measured equivalent age is controlled to be within 6.7%.