SO_3对水泥粉煤灰稳定碎石力学与抗干缩开裂性能的影响

Influence of SO_3 on Mechanical Performance and Dry Shrinkage Cracking Resistance of Cement-Fly Ash Stabilized Crushed-Stones

通过测量不同SO3含量下水泥粉煤灰稳定碎石的28 d劈裂强度、28 d抗压回弹模量、胀缩性能以及干缩抗裂指数,分析了SO3含量对水泥粉煤灰稳定碎石力学与抗干缩开裂性能的影响.结果表明:在粉煤灰掺量为10%(质量分数)的情况下,当SO3含量为5.8%(质量分数)时,其能显著改善水泥粉煤灰稳定碎石的力学与抗干缩开裂性能,但当SO3含量为8.8%时,会使该材料的结构破坏、力学性能恶化.另外,对微膨胀补偿基层干缩的作用机理以及SO3在水泥粉煤灰结合料中的作用机理进行了探讨.

The cement-fly ash stabilized crushed-stones were prepared with different SO3 contents and their 28 d splitting strength, 28 d compressive resilient modulus, expansion-shrinkage and dry shrinkage anticracking coefficients were studied. On this base, the influence of SO3 content on mechanical performance and dry shrinkage cracking resistance of the materials was investigated. It is proved that when SO3 content is 5.8% （by mass）, the mechanical performance and dry shrinkage cracking resistance of cement-fly ash stabilized crushed-stones with 10% （by mass） fly ash is improved. However, the structure and the mechanical performance of the materials are deteriorated if the SO3 content reaches 8.8%. The mechanism of compensating shrinkage by micro-expansion in pavement base and the function of SO3 on cement-fly ash binder are also explored in the study.