A type of light weight concrete mainly consisting of cement paste with randomly distributed air bubbles introduced by foaming agents. It has superior thermal response, good filling properties, fire resistance and low density compared to other types of concrete. Foam concrete can also be easily moulded to form different shapes and enables faster construction.
The aim of this study is to produce and test the mechanical properties of lightweight foam concrete (LFC) incorporating natural/artificial lightweight aggregates (LWA), in particular its compressive strength, flexural strength and porosity. A Portafoam TM2 system was used to create the stable foam for LFC at densities of 35-40 kg/m3. The base mix is made up of cement, fine filler, clean water and surfactant. The base mix was dry-mixed for 30 s, before the addition of water, superplasticizer and stabiliser. The mixture was then mixed at a shear intensity of 1000 rpm for 2 min and the foam was produced concurrently. The concrete and foam were then mixed together to obtain a 1:3 ratio of paste to foam. The LFC specimens were tested 28 days after mixing for compression, flexural and porosity.
The results showed that the supplementary cementitious materials like fly ash and ground granulated blast furnace slag have been utilized broadly in the manufacture of LFC. The amount of fly ash and white GGBFS ranged between 30% – 70%, which reduces the amount of cement used and is economical. Silica fume can also be added to increase the strength; at a rate of 10 percent by mass.