全取代风积沙砂浆工作性与干缩性能研究

Research on Workability and Dry Shrinkage Properties of Full-replaced Aeolian Sand Mortar

在对乌海地区风积沙性能进行分析的基础上,研究了全取代风积沙砂浆的工作性。结果表明,在相同胶砂比、水胶比条件下,与标准砂砂浆进行对比,风积沙砂浆流动度明显较小。胶砂比较低时,水泥对风积沙的包裹性差,难以保证砂浆的工作性。通过不同胶砂比风积沙砂浆实验和减水剂超掺实验证明,当胶砂比提高到1∶2时,才能得到具有一定流动性的全取代风积沙砂浆。测试了不同胶砂比、不同粉煤灰掺量的全取代风积沙砂浆的干燥收缩,结果表明,全取代风积沙砂浆的干缩明显比标准砂大,而粉煤灰的掺入能够减少其干缩,当粉煤灰掺量为水泥的50%时,风积沙砂浆干缩小于标准砂砂浆。

Based on the analysis of the properties of aeolian sand in Wuhai, the working performance of fully-replaced aeolian sand mortar was studied. The experimental results show that compared with the standard sand mortar under the same binder-sand ratio and water-binder ratio, the fluidity of aeolian sand mortar is obviously lower. When the cement-sand ratio is relatively low, the cement has poor package property to aeolian sand and it is difficult to ensure the workability of the mortar. The aeolian sand mortar experiment and superplasticizer super-mixing experiment under the different binder-sand ratio are carried out, and it’s proved that when binder-sand ratio increases to 1∶2, a fully-replaced aeolian sand mortar with certain fluidity can be obtained. The dry shrinkage performance of fully-replaced aeolian sand mortar with different bindersand ratio and fly ash content was tested. The results show that the dry shrinkage of the fully-replaced aeolian sand mortar is significantly larger than that of the standard sand, and the incorporation of fly ash can reduce its shrinkage. When the fly ash content is 50% of the cementitious material, the dry shrinkage of aeolian sand mortar is smaller than that of standard sand.