Fly ash, a byproduct from coal-fired thermal power plants, is a pozzolanic material recognized as a valuable resource that can be added to construction materials to form cementitious compounds when in contact with water. Cenospheres, hollow, spherically shaped particles that are mostly open-pore type in nature, are one of the most important value-added materials or subproducts that mix with fly ash. This is due to the distinctive properties of cenospheres, such as being lightweight, good flowability, chemically inertness, good insulation, high compressive strength, and low thermal conductivity, which enable them to be widely used in many industrial applications. Cenospheres have become a highly in-demand material as a filler or additive in many specialized applications, such as in lightweight cement, polymeric composites, automotive brake rotors, and differential covers, mullite-coated diesel engine components, and electromagnetic shielding and energy absorption applications. Applications for cenospheres as a construction material have been found, such as in lightweight thermal insulation composite, lightweight sound-absorbing structural material with cenosphere-reinforced cement and asphalt concrete, and lightweight concrete. It has been recently reported that cenospheres are used as an additive or filler in polymer concrete matrix for manufacturing composite beams and composite railway sleepers. With their spherical and hollow morphologies, cenospheres are particularly promising, with high resistance to crack propagation. The density of cenospheres varies from 0.2 g/cc up to 2.6 g/cc. The availability of such low-density (