Mechanical Behavior of Thin-Laminated Cementitious Composites Incorporating Cenosphere Fillers

This study evaluates the suitability of fly ash cenosphere (FAC) for use in thin laminated cementitious composites (LCC). Laminated cementitious composites are reinforced concrete elements constructed of hydraulic cement mortar and closely spaced layers of mesh reinforcement. In this study, FAC was used in the mortar matrix instead of sand (a typical ingredient of hydraulic cement mortar). Various weight fractions (40, 50, and 60%) of FAC were used in preparing the mortars while discontinuous polyvinyl alcohol (PVA) fibers were also incorporated, in small amounts (0.50%), for improved matrix stiffness. Galvanized iron welded wire mesh and fiberglass woven mesh were used as primary reinforcement in LCC specimens. The resulting matrixes and LCC specimens were tested for mechanical properties and flexural performance. The properties of developed LCCs incorporating FAC were also compared with their counterparts fabricated with high-strength silica sand mortar matrix. Fly ash cenosphere was determined suitable in producing structural lightweight LCCs (specific strength range; 7.52 to 26.65 kPa/kgm(-3) [17.47 to 61.92 psi/pcf]) with excellent mechanical properties while having improved the characteristic brittleness associated with lightweight composites. Further, FAC-incorporated LCCs exhibited better ductility even at lower peak flexural strength. A 50% FAC weight fraction has been proved to be the most efficient in producing strong lightweight LCCs for practical applications as structural elements.