Properties of Concrete Incorporating Recycled Post-Consumer Environmental Wastes

The use of sustainable technologies such as supplementary cementitious materials, and/or recycled post-consumer environmental wastes is widely used in concrete industry in the last decade. This paper presents the results of a laboratory investigation of normal concrete containing sustainable technologies. Twenty one mixtures (21) were prepared with different combinations of silica fume, fly ash, olive’s seed ash, and corncob ash (CCA). Fresh and hardened concrete properties were measured, as expected the inclusion of the sustainable technologies affected both fresh and hardened concrete properties. Based on the results obtained in this study and the analyses conducted, the following observations were drawn: replacing the cement by olive’s seed ash or CCA has a significant effect on fresh concrete workability. Olive’s seed ash increased the slump by more than 200 % compared to the control mixtures. The compressive strength of mixtures containing olive’s seed ash showed by 45 and 75 % decrease compared to the control mixtures. The 28 days compressive strength of mixtures produced by CCA of 10 % replacement decreased by 41 % compared to the control mixture.