Supplementary cementitious materials (SCMs) are natural or industrial by-product materials which are used to improve the performance, durability, and sustainability of concrete mixtures. Motivated by the recent reports on shortage of conventional SCMs, impure calcined clays (CCs) are receiving attention as abundant alternative pozzolans for concrete. In this study, a clay slurry resulting from washing aggregates in a commercial sand and gravel pit was investigated. This source clay was dried and calcined, and the properties and pozzolanic performance of the resulting CC was evaluated. It was observed that despite having a large (>50%wt.) inert quartz content, the CC met all ASTM C618-19 (AASHTO M295) requirements for natural pozzolan. A pavement-grade concrete mixture containing 20%CC as a cement replacement (by weight) produced desired workability and fresh and hardened air content. Strength development was slightly below the control. The use of CC improved the durability of concrete with respect to chloride penetration, alkali–silica reaction, and drying shrinkage in comparison with a control (100% Portland cement) mixture. In addition, ternary limestone-calcined clay–cement and slag-calcined clay–cement mortar mixtures showed excellent strength development while replacing nearly 50% of the Portland cement.

补充胶凝材料（SCM）是天然或工业副产品材料，用于改善混凝土混合物的性能，耐久性和可持续性。受近期有关常规SCM短缺的报道的推动，不纯的煅烧粘土（CC）作为混凝土的丰富替代火山灰受到关注。在这项研究中，研究了在商业沙子和砾石坑中洗涤骨料产生的粘土浆料。将该来源粘土干燥并煅烧，并评估所得CC的性能和火山灰性能。据观察，尽管惰性石英含量高（> 50％wt。），但CC满足了天然火山灰的所有ASTM C618-19（AASHTO M295）要求。包含20％CC作为水泥替代品（按重量计）的路面级混凝土混合物可产生所需的可加工性以及新鲜和硬化的空气含量。力量发展略低于控制。与对照（100％波特兰水泥）混合物相比，CC的使用提高了混凝土在氯化物渗透，碱-二氧化硅反应和干燥收缩方面的耐久性。此外，三元石灰石煅烧的粘土-水泥和矿渣煅烧的粘土-水泥砂浆混合物显示出优异的强度发展，同时替代了近50％的波特兰水泥。与对照（100％波特兰水泥）混合物相比，干燥收缩率更高。此外，三元石灰石煅烧的粘土-水泥和矿渣煅烧的粘土-水泥砂浆混合物显示出优异的强度发展，同时替代了近50％的波特兰水泥。与对照（100％波特兰水泥）混合物相比，干燥收缩率更高。此外，三元石灰石煅烧的粘土-水泥和矿渣煅烧的粘土-水泥砂浆混合物显示出优异的强度发展，同时替代了近50％的波特兰水泥。