Experimental Investigations of the Properties of Foam Concrete for Utilisation as Crushed Lightweight Aggregates in Building Slabs

Foam concrete is examined for use as a lightweight aggregate in concrete for building slabs. Crushed foam concrete should substitute LECAs in areas where LECAs are inaccessible. Suitable foam concrete mixes with and without admixtures and fine aggregates (limestone, stone dust, and micro silica) are tested to determine the densities (approx. range 550–1100 kg/m3), compressive strengths (approx. 0–8 MPa), and crushing potential measures as Percentage Mass of Useful Material After Crushing (approx. 70–90%). A mixing technique is developed using high revolutions. Some mixes show potential by providing a combination of density below 800 kg/m3, an adequately high compressive strength to be handled (>1 MPa), a low cement content (below 300 kg/m3), and a sufficiently high level of larger fragments above 4 mm when crushed (>80%). The results show that oven curing and curing beyond one day do not have a significant benefit. The investigation shows potential for two mixes, though developing the desired mixes further and studying a more consistent industrialised crushing method is recommended.