Valorization of Metal Milling Waste in Cement Based Mortars Modified by Replacement of Cement Kiln Dust

Abstract

Recycling industrial by-product materials waste has become an attractive topic of materials research in civil engineering. These industrial by-product materials waste must be managed responsibly to insure a clean environment. Our research was conducted with the aim of investigating the effect of the addition of two industrial by product materials waste: metal milling waste (F) and cement kiln dust (CKD) in cement paste/mortar, as well as how to assess the influence of CKD substitution on the mechanical properties of cement pastes to create a new hydraulic binder based on partial replacement. An experimental program was conducted on samples of cement paste prepared at three CKD content (5%, 10%, 15% wt. of cement) and new mortars were prepared by: partial replacement of ordinary Portland cement by CKD at 5% by mass; and the simple addition of metal milling waste at three different percentages of (10%, 20%, 30% wt. of binder). Chemical, Micro structural analysis and mineralogical analysis have been carried out using XRD and FT-IR techniques, the mechanical strength, shrinkage, swelling, setting times, were analyzed.<br/> Test results after a 28-day hardening period indicated that when the increase in the CKD replacement, the expansion obtained in the mixed cement pastes increase and the initial and final setting time decreases. The improvement of the strength of cement kiln dust (CKD) in the mixed cement pastes is low, it was found that adding 5% of cement weight CKD is the appropriate percentage for utilizing in the manufacturing of mortars. the addition of metal milling wastes in mortars leads to a considerable improvement of mechanical strengths compared to the reference mortar. The strength increases when the percentage of Metal milling wastes additions increases until an optimum (20%).