铁尾矿砂水泥土强度特性及微观孔隙研究

Study on strength characteristics and micropores of cement soil from iron ore tailing

为了提高固体废料的二次利用率,改善水泥土的力学性能,采用无侧限抗压强度试验和氮气吸附试验等试验方法,探究了铁尾矿砂对水泥土力学特性及微观孔隙的影响,试验结果表明:随着铁尾矿砂掺量的增加,水泥土的无侧限抗压强度呈先增加后减小的趋势,在铁尾矿砂20%~30%时抗压强度达到最大值;相同水泥掺量下,铁尾矿砂水泥土的比表面积随铁尾矿砂掺量的增加呈先增大后减小的趋势,在铁尾矿砂20%时,比表面积最大;铁尾矿砂水泥土的孔隙组成为:少量的微孔、大量的中孔以及一定数量的大孔;随着铁尾矿砂掺量和水泥掺量的增加,水泥土孔隙中的有害孔持续减小,少害孔持续增加,平均孔径减小。

In order to improve the secondary utilization rate of solid waste and improve the mechanical properties of soil-cement,the unconfined compressive strength test and nitrogen adsorption test are used to explore the influence of iron tailing ore on the mechanical properties and microscopic pores of soil-cement.The test results show that:with the increase of iron tailing ore content,the unconfined compressive strength of soil-cement increases first and then decreases,and reaches the maximum value when iron tailing ore content is 20%~30%;under the same cement content,the relative surface area of soil-cement of iron tailing ore increases first and then decreases with the increase of iron tailing ore content,and the specific surface area reaches the maximum when the iron tailing ore content is 20%.The pore compositions of the cement soil of iron tail ore are as follows:a small number of micropores,a large number of mesopores and a certain number of macropores.With the increase of iron tailing ore content and cement content,the harmful pores in soil-cement pores continue to decrease,the less harmful pores continue to increase,and the average pore size decreases.