The aim of this study is to develop Lightweight self-compacting concrete (LWSCC) mixtures using locally sourced waste materials such as Expanded Polystyrene Beads (EPS) and Waste Plastic Fibers (WPFs) which are all available abundantly available in Republic of Iraq at little or no cost. The fresh, hardened and mechanical properties of these LWSCC were studied, followed by results analysis. Five different mixes of LWSCC were prepared in term of WPF content (0.25, 0.5, 0.75, 1.0, and 1.25 %), in addition to the control mix (R mix) and lightweight concrete (E mix) made of EPS content as a replacement of coarse aggregate. The study showed that the LWSCC produced with these waste materials were decreased the density (lightweight) of the concrete mixes as EPS tend to form more clumps, absorb water and make the mix dry. Therefore, concrete mixtures were adjusted accordingly to be able to offset the workability caused by the addition of EPS. The increase in WPF content decreased the workability due to clumping that occurred in the mixing phase. The analysis of mechanical properties of the LWSCFRC specimens revealed that there was not much improvement. While LWSCC with 100% of EPS replacement as coarse aggregates and 1.25% WPFs provides the best flexural toughness performance
The influence of concrete mixing water quality on the compressive strength of concretes was investigated in this study. During the study, the compressive strength (CS) of the concretes was determined at 7, 14, and 28 days age. This study used 8 types of water of varying qualities as concrete mixing water (water with 71 UTN impurity level, water with 250 UTN impurity level, water with 1000 UTN impurity level, well-sourced water, acidified water, and alkaline water). Potable water was used as reference water. The results indicated that the lowest CS has been obtained by using alkaline water at a concrete age of 7 days while the usage of water with 250 UTN impurity level as a concrete mixing water yielded the highest CS. in addition, the lowest CS has been obtained when using a mixing water of alkaline at a concrete age of 14 days while the highest CS resulted from using water with 71 and 250 UTN impurities levels. Furthermore, the usage of water with 71 UTN impurities level and an acidic water as a concrete water mixing gave the lowest CS at twenty eight days concrete age, while using magnetic water and water with 250 UTN impurities as concrete mixing water resulted in the highest CS. The use of water with 250 UTN impurities as concrete mixing water favored CS development at all concrete ages. These obtained results have shown a various effects of different impurities which significantly indicate that only a few water impurities affect the concrete’s CS seriously..