Utilization of cement kiln dust (CKD)‎ as a partial replacement of cement in mortar and concrete

الملخص EN

This research examines the potential of using cement kiln dust (CKD) as a blended cement material to study the effects of this partial replacement on the most important properties of cement paste, mortar and concrete.

The levels of replacement of cement by an equal amount of the (CKD) dust were (5, 10, 15, 20, 25, 30) % by weight.

A reference cement paste, mortar and concrete mix were also prepared for comparison.

The tested properties included the initial setting time of each cement paste and the compressive and tensile strengths of mortars and concrete.

Water curing was used for all specimens and the strength tests were carried out at (3, 7, 28) days.

Results of experimental data reveal that (CKD) can be effectively used as a partial cement material.

The initial setting time of the cement paste is decreased with the increase of (CKD) content due to the high amount of lime and alkalis in (CKD).

Besides, the compressive and tensile strengths of the blended cement and concrete specimens were also found to be comparable to the strengths of the reference mixes at all levels of replacement.

Generally, it was indicated that the compressive strength decreased with the increase of (CKD) content.

The (10)% replacement level had the best results in the compressive strengths of mortars and concretes at all ages in comparison to the reference mixes, also this level of substitution had a significant effect on the tensile strength of the mortars and concretes at early ages.

It was noted that (15) % (CKD) replacement maintained the higher tensile strength of mortars at (7, 28) days, whereas a (25) % (CKD) had a similar effect but at (3, 28) days.