Abstract

The effect of lead (Pb) present in mixing water on compressive strength, setting times, soundness and magnesium sulfate attack on high strength cement mortar was experimentally evaluated. Cement mortar specimens were cast using deionised water and lead (Pb) spiked deionized water for reference and the test specimens as mixing waters respectively. On comparison with reference specimens, at higher concentrations of lead in mixing water, test samples had shown considerable loss of strength, and also their setting times had significantly increased. However, at 2000 mg/L concentration of lead (Pb), the compressive strength marginally increased. Apart from that when reference specimens and test specimens were immersed in various concentrations of magnesium sulfate solution at different immersed ages, the loss in compressive strength was found  to have been slightly less in test specimens than that in reference specimens. X-ray diffraction (XRD) technique was employed to find out main compounds.

Key words: Cement mortar, lead (Pb), silica fume (SF), magnesium sulfate, superplasticiser (SP).