水泥稳定碎石混合料拌和均匀性分析

Analysis of Mixing Uniformity of Cement Stabilized Macadam Mixture

为研究不同拌和方式对水泥稳定碎石混合料拌和均匀性影响,首先进行配合比设计,然后对拌缸搅拌、振动搅拌、无振搅拌三种不同拌和方式采用筛分试验、EDTA滴定试验进行对比分析.结果显示:各关键筛孔通过率、水泥EDTA滴定结果变异系数排序均为:拌缸搅拌>无振搅拌>振动搅拌,其中水泥滴定结果显示拌缸搅拌与无振搅拌相差不大,且振动搅拌变异系数较二者减小约50%.结果表明:相较传统拌缸搅拌工艺,采用振动搅拌可有效提高水稳混合料的级配均匀性,且未开振的无振搅拌较传统拌缸搅拌均匀性仍有调高;而振动搅拌只有在开振作用下才能有效提高水泥在混合料中的拌和均匀性.振动搅拌可有效改善混合料强度形成均匀性,减少由于强度不均匀导致的裂缝产生.

In order to study the influence of different mixing methods on the mixing uniformity of cement stabilized macadam mixture,the mix proportion design was carried out at first,and then the screening test and EDTA titration test were used for comparative analysis of three different mixing methods:mixing in mixing tank,vibration mixing technology and vibration-free mixing.The results show that the pass rate of each key sieve hole and the variation coefficient of EDTA titration results of cement are in the order of mixing in cylinder>vibration-free stirring>vibration stirring.The cement titration results show that there is little difference between mixing in cylinder and vibration-free stirring,and the variation coefficient of vibration stirring is reduced by about 50%.The results show that,compared with the traditional mixing technology,vibration mixing can effectively improve the gradation uniformity of water-stable mixture,and the uniformity of vibration-free mixing without vibration is still higher than that of traditional mixing technology.However,vibration mixing can effectively improve the mixing uniformity of cement in the mixture only under the action of open vibration.Vibration stirring can effectively improve the uniformity of strength formation of mixture and reduce cracks caused by uneven strength formation.