Lightweight Foamed Concrete Mixture for Structural Use

Foamed concrete is currently studied to investigate its feasibility to be used structurally to produce lightweight concrete mix that is workable and has sufficient mechanical properties. This encouraged this research to design foamed concrete mix to be used in the construction industry. The main parameters that shall be satisfied for structural use are the workability, density less than 1900 kg/m(3) and minimum cylinder compressive strength of 17 MPa (2500 ksi) based on ACI 213R-87. In this paper, fourteen different foamed concrete mixes are designed and tested to investigate their applicability. As fly ash quality affects foamed concrete permeability and as foamed concrete has low resistance to concentrated stresses, the proposed mixes do not contain fly ash and are reinforced with polypropylene fibers. The effect of water-to-cement ratio, sand-to-cement ratio, polypropylene fibers content, and the foam agent content are investigated. It is found that the compressive strength increases with the increase in density. The optimum sand-to-cement ratio is 1:1, water-to-cement ratio is 0.4, and the polypropylene fibers content is 1% by weight of cement. A relationship of splitting tensile strength relative to compressive strength is proposed.