In this work, the mechanical and transport properties of recycled aggregate concrete (RAC) modified with limestone powder were studied. The results indicate that replacing 10 wt% cement with limestone substantially improves the compressive strength of RAC. A better resistance to chloride and water ingress can also be achieved owing to the decreased pore connectivity. The initial sorptivity is found to increase linearly with increasing permeable voids content. Mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM) analyses demonstrate that adding limestone leads to a refinement of pore structure and densification of both bulk paste and interfacial transition zone, respectively. X-ray diffraction (XRD) patterns suggest that incorporation of limestone prevents the transformation from ettringite (AFt) to monosulfate (AFm), thus increasing the total volume of hydration products. Thermogravimetry and differential scanning calorimetry (TG/DSC) analyses confirm an improved hydration process in RAC containing limestone, explaining for the enhanced mechanical and transport properties.

在这项工作中，研究了用石灰石粉改性的再生骨料混凝土（RAC）的机械性能和运输性能。结果表明，用石灰石代替10 wt％的水泥可显着提高RAC的抗压强度。由于减少了孔的连通性，因此还可以更好地抵抗氯化物和水的侵入。发现初始吸着率随着渗透性孔隙含量的增加而线性增加。汞侵入孔隙率法（MIP）和扫描电子显微镜（SEM）分析表明，添加石灰石分别可改善孔隙结构，并分别疏松块状糊料和界面过渡区。X射线衍射（XRD）图表明，掺入石灰石可防止钙矾石（AFt）向单硫酸盐（AFm）的转化，因此增加了水合产物的总体积。热重分析和差示扫描量热法（TG / DSC）分析证实了含RAC的石灰石中水化过程的改善，解释了增强的机械和运输性能。