Green lightweight ferrocement incorporating fly ash cenosphere based fibrous mortar matrix

This paper presents an experimental assessment on the suitability of fly ash cenosphere (FAC), a waste residue from coal fired power plants, for use in lightweight ferrocement construction. Ferrocement is a special type of thin walled reinforced concrete constructed of hydraulic cement mortar and closely spaced layers of steel wire mesh. In this study, the mortar mix was prepared by replacing the sand (a typical ingredient of ferrocement matrix) with FAC at 40 %, 50 % and 60 % FAC weight fractions in mortar. Single and double layers of galvanized iron welded wire mesh were used as the main reinforcement while small volume fraction (0.50 %) of PVA fibers was also added as a discontinuous reinforcement resulting in a hybrid composite. The mortar mixes were tested for mechanical strength including compressive strength, elastic modulus and Poisson's ratio whereas the ferrocement composites were evaluated for flexural performance. The ferrocement composite properties were compared with high strength quartz sand mortar matrix as well. FAC was found to be excellent in producing structural lightweight ferrocement composites (density 1332.09–1457.89 kg/m³) with excellent mechanical properties. The PVA fibers helped improve the inherent brittleness of FAC composites. Thus, lightweight ferrocement elements with higher specific strength (18.39–26.65 kPa/kgm⁻³), flexural strength (14.47–28.13 MPa), and tensile strength (5.69–11.06 MPa) can be produced, with utilizing FAC waste residue. The use of such composites in construction can promote sustainable development by minimizing waste.