Effects of Sludge Water from Ready-Mixed Concrete Plant on Concrete Containing Admixtures

Abstract

This research was aimed to study the effect of sludge water from ready-mixed concrete plantto replace mixing water in concrete containing admixtures. The admixtures used in this study werefly ash and superplasticizer. The experimental procedures were performed to study the characteristicof sludge water as concrete mixing water and to determine the optimum total solid content ofsludge water in cement paste by varying the percentage of total solid content in sludge waterbetween 0.5%, 2.5%, 5%, 7.5%, 10%, 12.5% and 15%. The selected sludge water was used formixing and studying the behavior of concrete. Test results showed that sludge powder, consisting ofhydration products and small particles, has more loss of ignition value than cement type I and flyash. Total solid content of sludge water, found in the range of 54,100-61,300 mg/l. for the criteria ofASTM C94, had an influence on the compressive strength and setting time of cement paste. Thesludge water decreased an efficiency of concrete admixtures. Concrete mixed with sludge waterand admixtures has better mechanical and durability properties than concrete mixed with sludgewater only.

Keywords : Ready-mixed Concrete Plant / Recycle / Sludge Water