选取粉煤灰废弃物及价格低廉的聚丙烯纤维作为外掺剂，与内蒙古自治区中西部地区的红黏土一起制成一种特殊的水泥土。通过正交试验，研究水泥掺量、粉煤灰掺量、聚丙烯纤维掺量及混合体含水率对水泥土7 d 早期无侧限抗压强度的影响；然后利用电镜试验，从微观方面证明浆体的合理层理结构与纤维的固结加筋作用。结果表明，在一定的范围内，水泥掺量对其影响最大，其次为粉煤灰掺量，聚丙烯纤维掺量和混合体含水率的影响则较小，且最优配合（质量分数）比为水泥10％，粉煤灰16％，聚丙烯纤维0．12％，混合体含水率18％。第9组强度高于第1组。并对第9组（水泥掺量10％，粉煤灰掺量16％，纤维掺量0．10％，含水率16％）试块进行应力-应变曲线拟合，得出曲线上升段满足三次多项式方程，下降段满足二次多项式方程。%The red clay in the central and western regions in Inner Mongolia autonomous region was selected and the fly ash waste and polypropylene fiber as the additive agent was applied tomake a kind of special cement-soil,which is has the economic benefi-cial and environmental effect.The orthogonal experiment was applied to study the influence of the dosage of cement,fly ash,pol-ypropylene fiber and mixture moisture content on 7 days early unconfined compressive strength of cement-soil.It is concluded that in a certain range,the cement content has the greatest effect ,followed by the dosage of fly ash,and the influence of the dosage of polypropylene fiber and mixture moisture content is smaller.The optimal mixture ratio is cement 10%,fly ash 16%,polypro-pylene fiber 0.12%,mixed moisture content 18%.Then SEM test demonstrated that reasonable bedding structure of the slurry and the reinforcement and consolidation effect of fiber is the reason that the strength of 9 group is higher than group 1 from the micro aspects.The stress-strain curve fitting was drawn with the 9 group block (cement content 10%,fly ash 16%,fiber con-tent 0.10%,the mixed moisture content 16%).It is concluded that the rising of the curve fits the cubic polynomial equation,and the decline of the curve fits quadratic polynomial equation.The experiment results can provide certain reference for practical engi-neering application.
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