聚合物改性水泥胶浆流变性能试验

Experiment of Rheological Property of Polymer Modified Cement Paste

针对目前道路工程领域有关聚合物改性水泥胶浆流变性能的系统研究较少的现状,试验研究了丁苯聚合物乳液对水泥胶浆力学性能的影响,通过Brookfield R/S Plus旋转粘度测试仪,分析了高效减水剂、剪切速率、丁苯聚合物乳液以及矿物掺和料对聚合物改性水泥胶浆流变性能的影响。试验结果表明:加入丁苯聚合物乳液能够显著提高水泥胶浆的柔韧性,降低其脆性;高效减水剂对聚合物改性水泥胶浆的流变性能有显著影响,其屈服应力及塑性粘度随高效减水剂掺量的增大而逐渐减小;聚合物改性水泥胶浆的流变曲线符合宾汉姆流体模型(Bingham fluidmodel),随着丁苯乳液掺量的不断增加,水泥胶浆的流变性能得以逐渐改善;聚合物改性水泥胶浆的剪切应力及塑性粘度随着粉煤灰掺量的增大出现一定程度的增长,随着矿粉掺量的逐渐增大,其剪切应力及塑性粘度出现一定程度的下降,但下降幅度并不明显。

At present, it is short of research on the rheological property of polymer modified cement paste in road engineering. The influence of SBR polymer latex on mechanical property of polymer modified cement paste was studied by test. The effects of superplasticizer （SP）, shear rate, SBR polymer latex and mineral admixtures on the rheological property of polymer modified cement paste were analysed using Brookfield R/S Plus rheometer. The results indicate that （ 1 ） adding SBR polymer latex can obviously improve the flexibility of cement paste and reduce its brittleness; （2） SP has a significant influence on the rheological property of polymer modified cement paste, the yield stress and plastic viscosity of polymer modified cement paste generally decrease with the increase of the amount of SP; （3） the rheology curve of polymer modified cement paste accords with the Bingham fluid model, its rheological property improves with the SBR polymer latex content gradually increases; （4） with the increasing of fly ash, the shear stress and plastic viscosity of polymer modified cement paste gradually increases to a certain extent, while with the gradual increase of granulated blast-furnace slag （GBFS） content, the shear stress and plastic viscosity of polymer modified cement paste decrease to a certain extent but unsignificantly.