Abstract: “Water hyacinth(W-H) has an adverse effect on Nile river in Egypt , it absorb a high quantities of water, it is need to serve the quantities arrived ( 55500 million m3) especially in this time, so by burning W-H it can used in concrete mix to reduce the permeability of concrete. In this study, the effect of W-H on concrete properties ( fresh- hardened) were studied, slump of concrete as a fresh properties, compressive strength, splitting tensile strength as mechanical properties, mass transport by Isat , microstructure by XRD and thermal gravimetric analysis (TGA). This paper presents a study on the properties of concrete prepared with two aggregate types, namely gravel and dolomite. Various concrete mixes made with gravel and dolomite which blended with proportions 1:0,0:1,1:1,1:2 and 2:1, respectively with different W-H ratios of 0,0.5,1.0 ,2.0 and 5.0% by mass of cement at w∕c 0.50 for different mixes. The results showed that mechanical properties of concrete developed at 2% W-H for”

Keywords: Water hyacinth, compressive strength, mass transport, Concrete.