石粉对混合砂高性能混凝土早期体积稳定性的影响

Influence of micro fines on early volume stability of high-performance concrete mixed sand

通过调整机制砂与河砂的不同比例来控制混合砂中的石粉含量为0、3%、5%、7%,对比研究不同石粉含量的混合砂对高性能混凝土早期体积稳定性的影响。研究结果表明:在早期塑性开裂性能上,纯机制砂高性能混凝土和混合砂高性能混凝土的性能均比纯河砂高性能混凝土的要好,当混合砂石粉含量为5%,混凝土的早期塑性开裂性能最优;自收缩性能的发展规律均为前期增长速度较快,到后期逐渐趋于稳定状态,且石粉含量为5%的混合砂高性能混凝土的自收缩性能最好。

By adjusting the manufactured sand and river sand in different proportions to control the micro fines content is 0,3%, 5% and 7% in the mixed sand.Comparative study of the influence of different micro fines content on early volume stability of high-performance concrete mixed sand.The results indicates that the early anti-cracking capability of manufactured-sand concrete and mixed-sand concrete is higher than that of river-sand concrete, especially the mixed-sand concrete which with the micro fines in proportion of 5% achieves the most desired early anti-cracking capability.Furthermore,the law of self-shrinkage is observed to be high initially before gradually being stable at the late stage and high-performance concrete mixed sand with 5% micro fines obtained the most desired properties in self-shrinkage.