水泥粉煤灰稳定碎石强度增长特性

Strength growth characteristics of cement and fly-ash stabilized crushed-stones

为了评价水泥粉煤灰稳定碎石强度增长特性，通过不同龄期无侧限抗压强度试验和劈裂试验，研究了不同粉煤灰掺量下水泥粉煤灰稳定碎石强度变化情况。结果表明：粉煤灰的掺人，对水泥稳定碎石早期抗压强度和劈裂强度都有影响，掺量越大早期强度越低；掺加粉煤灰对长期强度有利，就提高长期强度而言，粉煤灰最佳掺量约为10％；由于7d抗压强度不足以反映掺粉煤灰的水泥稳定碎石强度特性，建议采用7～90d强度增长率作为评价其强度潜能，在实际工程中应适当降低其7d强度要求。

In order to evaluate the strength growth characteristics of cement and fly-ash stabilized crushed stones, the strength variety of different fly-ash mixing proportion is studied by unconfined compressive strength test and splitting test for different ages. The results show that incorporation of fly-ash would reduce the compressive strength and splitting strength of cement-stabilized crushed stones in early stage. And the greater the incorporation, the lower the early strength is. Mixing with fly-ash would benefit the long-term strength, and the optimum mix content of fly-ash is about 10%. In view of compressive strength for 7 day ages could not adequately reflect the strength characteristics, the strength growth rate between 7 day ages and 90 day ages is suggested as the evaluation index of the strength potential of stabilized crushed stones. And the strength requirement of 7 day ages should be reduced properly in project practice.