Mechanical performance of eco-friendly self-compacting concrete (SCC) mixtures and two-way slabs partially containing cement kiln dust as cement replacement and internally reinforced with waste plastic mesh

Abstract

A large quantity of cement kiln dust (CKD) is produced annually during the production of Portland cement. The majority of the produced CKD remains unused except in specific cases related to soil stabilization projects. The current research investigates the production of self-compacting concrete (SCC) mixtures, in which CKD is used as a substitute for cement in different weight proportions, 3 %, 6 %, 9 %, 12 %, and 15 %. The hardened mechanical properties of SCC, such as compressive strength, splitting tensile strength, and flexural strength, as well as the fresh state characteristics (i.e., slump flow diameter, T500, V-funnel, and L-box tests), were recorded and compared with the control mixture which was entirely cast using cement. Results revealed that with an increase in the CKD content beyond 6 %, the slump flow diameter of SCC mixtures significantly decreased. Also, the increase ratios in the V-Funnel flow time for self-compacting concrete mixtures, when replacing cement with CKD ratios of 3 %, 6 %, 9 %, 12 %, and 15 %, were 13.3 %, 30 %, 46 %, 58 %, and 66.7 % respectively, compared with the reference mixture. Additionally, the impact behavior of two-way SCC slabs cast using CKD ratios ranging from 3 to 15 % and internally strengthened using various patterns of recycled plastic mesh was investigated. Strengthening the SCC slabs using two layers of recycled plastic grids proved to be effective in preventing the projectile from penetrating the whole thickness of the SCC slabs, regardless of the CKD content.