Abstract: As lime-flyash mixture , a kind of semi-rigid base course material used in highway engineering , has usually very low early strength, its application is confined .The paper studies on low active lime-flyash mixture strength properties with different additives at different ages.Through X-ray diffractometer and scan electron microscope tests, the mechanism of low active lime-fly ash mixture strength with additives is studied.The results show that early strength of lime-flyash mixture can be significantly improved with adding Na2SO4 and Na2CO3, late strength of lime-flyash mixture with Na2SO4 is super to Na2CO3 , where as early and late strength of lime-flyash mixture with Portland cement is weak.

Key words: lime-flyash, additives, strength, mechanism , X-ray diffractometer , scan electron microscope

摘要： 针对低活性二灰混合料,通过掺加不同的外加剂在不同龄期的无侧限抗压强度试验来研究强度特性,通过X光衍射和扫描电镜研究外加剂对二灰混合料强度改善的机理.结果表明掺加Na2SO4和Na2CO3可显著改善二灰混合料的早期强度,掺加Na2SO4对二灰混合料的后期强度改善要优于掺加Na2CO3,掺加水泥无论早期还是后期强度改善效果相对较差

关键词: 石灰粉煤灰, 外加剂, 强度, 机理, X光衍射, 扫描电镜