针对机制砂的石粉含量对混凝土抗渗性及体积稳定性的影响进行了相应研究。实验表明,C80机制砂混凝土的氯离子扩撒系数均较低,随石粉含量的增加,氯离子扩撒系数呈线性增长;弹性模量随石粉含量的增加有下降的趋势,5%含量以下时高于河砂混凝土;在早期,机制砂混凝土的干燥收缩随着石粉含量的增大而增大,而在60 d以后5%石粉含量混凝土的干缩最小,试验证明,石粉含量在7%以下时,机制砂混凝土耐久性与体积稳定性较好,与河砂混凝土相当,一定量的石粉不会对混凝土渗透性与体积稳定性产生不利影响。

Effects of Stone-dust on Resistance to Chlorine Ion Permeating and Volume Stability of C80 Manufactured-sand ConcreteCHEN Biao1,2,WANG Ji-liang2,YANG Yu-hui3,ZHOU Ming-kai2(1.Super-Highway Industry and Commerce Development Limited Company,Wuhan 430051,China;2.Key Laboratory for Silicate Materials Science and Engineering of Ministry of Education,Wuhan University of Technology,Wuhan 430070,China;3.China Jingye Engineering Corporation Limited,Beijing 100088,China)The effects of the stone-dust(SD) content in manufactured-sand(MS) on the permeability of chloride ion and volume stability of C80 MS concrete are investigated.The results show that chloride ion diffusion coefficient of C80 MS concrete is very lower,but it increases linearly with the increment of SD content,while elastic modulus reduces gradually.And when SD content is under 5%,elastic modulus of MS concrete is higher than that of natural sand concrete.With the increment of SD content,dry shrinkage of C80 MS concrete increases in the early age,and that of MS concrete with 5% SD is the smallest after 60 days.As a result, when SD in MS is under 7%,SD does not deteriorate the durability and volume stability of C80 MS concrete,which is similar to that of the natural sand concrete.stone dust;C80 manufactured-sand concrete;impermeability;volume stability