The Case Study on Cubes Compressive Strength Variations for Different Water Sources in Dares Salaam City, Tanzania
Livingstone Swilla *
Department of Water Resources and Irrigation Engineering, Water Institute (WI), Dar es Salaam, Tanzania.
Mpima Zeddy
Department of Water Resources and Irrigation Engineering, Water Institute (WI), Dar es Salaam, Tanzania.
Yona Kimori
Department of Water Resources and Irrigation Engineering, Water Institute (WI), Dar es Salaam, Tanzania.
*Author to whom correspondence should be addressed.
Abstract
In this study the concrete compressive strength variations for different water sources in Dares Salaam city is presented. Concrete cubes were casted and cured for 7, 14 and 28 days using public fresh water and water samples collected from different borehole sources in Dar es Salaam city. The selected parameters (pH, chlorine content, sulphate content, TDS level and Electrical Conductivity) were analyzed in the laboratory for all water samples. The concrete was mixed with mixing ratio of 1:2:4. The concrete cube size measuring 150×150×150 mm in dimension was used. The results of the compressive strength of cubes showed that there was increase in strength at 7 days, 14 days and 28 days for cubes casted from Kawe, Riverside, Mabibo external, Makumbusho boreholes samples and public fresh water sample. Also results showed that pH, chlorine content (CL-), sulphates 
and Total dissolved solids (TDS) contribute to lower the compressive strength of the concrete when are in higher side and contribute to increase the compressive strength when are in lower side.
Keywords: compressive strength, concrete cubes, pH, chlorine content, sulphates, TDS