Properties of self-compacting mortar containing nano cement kiln dust

Abstract

Abstract Micro voids inside the cementitious materials mortar matrix drastically reduce the load carrying capacity of the mortar. Furthermore, the weak interface between the aggregate and mortar will promote the micro cracks initiation and cracks propagation. In this study, a nano cement kiln dust was added to the self-compacting mortar to enhances the microstructure of mortar and reduce the micro voids effectiveness. Nano cement kiln dust was prepared and used as additives to the self-compacting mortar in 1, 2, 3, 4, 5 wt.% to be used as cementitious sustainable materials. Cement kiln dust was prepared by grinding process until achieving to nano particle size, nano particle size was provided and checked by AFM and FESEM tests. Some self-compacting mortar properties was tested at 7, 28, and 90 days’ age. Fresh properties of the self-compacting mortar were evaluated by using mini flow table test and mini v-funnel test. The experimental results of self-compacting mortar shown that the mechanical properties which includes the compressive strength, direct tensile strength and flexural strength were increased as nano powder percentage increases. The physical properties such as porosity and total water absorption was decreased with the increase of nano powder contents. Dry density of the self-compacting mortar increased as nano powder percentage increase. The microstructure homogeneity and nano powder distributions of self-compacting mortar were explained by using FESEM images.