Effects of Blends of Cement Kiln Dust and Fly Ash on Properties of Concrete

摘要

This study evaluated concretes containing cement kiln dust (CKD) and fly ash todetermine whether satisfactory properties can be achieved for long-lasting performance in the field. The results indicate that certain combinations of cement, CKD, and fly ash may provide concretes with acceptable performance. Excessive expansions occurred when CKD blends were used in mortars subjected to cyclic wetting and drying at a temperature of 80 deg C (176 deg F). The addition of CKD to fly ash concrete did not improve strength development, but did reduce the coulomb values (AASHTO T277 or ASTM C 1202) at early ages, indicating reduced chloride permeability. However, at later ages fly ash concretes containing cement with an alkali content of 0.70% or above had very low coulomb values indicating high resistance to chloride penetration irrespective of the alkali activation.