再生细骨料对砂浆性能的影响

Influence of Recycled Fine Aggregate on Mortar Properties

摘要: 考虑三种水灰比(0.28, 0.30, 0.32)，四种再生细骨料置换率(0、30%、60%、100%)和四种浸泡时间(0, 2 h, 10 h, 24 h)，试验研究了再生细骨料对砂浆流动性、抗弯性能和水化特征的影响。试验结果显示：采用再生细骨料替代河砂会降低砂浆的流动性；砂浆抗压强度随再生细骨料置换率增加而减小，随水灰比的减小而小幅增加；浸泡时间对抗压强度的影响不显著；再生细骨料置换率和水灰比对砂浆抗折强度的影响可忽略。另外，电子扫描图像试验结果显示再生细骨料的使用利于促进砂浆中的水化反应。

Abstract: Considering three water-cement ratios (0.28, 0.30, 0.32), four replacement ratios of recycled fine aggregate (0, 30%, 60%, 100%) and four soaking times (0, 2 h, 10 h, 24 h), the experiment studied the effect of recycled fine aggregate on the fluidity, flexural performance and hydration characteristics of the mortar. The test results show that the use of recycled fine aggregate to replace river sand will reduce the fluidity of the mortar. The compressive strength of the mortar decreases with the increase of the replacement rate of recycled fine aggregate, and slightly increases with the decrease of water-cement ratio. The impact of soaking time on the compressive strength is not significant. The effect of the replacement rate of recycled fine aggregate and the water-cement ratio on the flexural strength of the mortar is negligible. In addition, the results of the electronic scanning image test show that the use of recycled fine aggregate is beneficial to promote the hydration reaction in the mortar.