Brazil is the world's largest producer of sugarcane, and its sugarcane industry generates a large amount of liquid and solid wastes, among them the sugarcane straw. Aiming to add value to this waste, sugarcane straw ash was produced by controlled burning at 700 °C and it was applied as mineral addition in cement composites. The ashes were characterized by the techniques of X ray fluorescence, X ray diffraction, laser particle size and specific surface area. The following composite properties were evaluated: water absorption, apparent porosity, bulk density, modulus of rupture, specific energy, elastic modulus and proportionality limit. The characterization of ash showed a high specific surface area and porosity and a halo of amorphicity was observed in the diffractograms. Composites produced with these ashes showed physical and mechanical characteristics similar to that of the control, allowing the partial replacement of Portland cement by this type of ashes.
pozzolan; agro industrial wastes; porosity
