The Influence of Powdered Crumb Rubber on the Mechanical Properties and Thermal Performance of Lightweight Foamed Concrete

<jats:title>Abstract</jats:title>
<jats:p>The introduction of powdered crumb rubber into the lightweight foamed concrete influenced various mechanical and physical behaviour of the concrete. The objective of this study is to investigate the influence of 15 %, 30 % and 45 % crumb rubber, in replacement of sand on the mechanical properties and thermal performance of lightweight foamed concrete. Compressive strength, flexural strength and thermal conductivity tests were conducted to evaluate the performance of crumb rubber lightweight foamed concrete. Laboratory results indicated that the strength properties of crumb rubber lightweight foamed concrete were weaker than those of conventional lightweight foamed concrete with a similar density. The compressive strength and flexural strength were reduced from 14.02 MPa to 10.66 MPa and 4.92 MPa to 3.06 MPa respectively, as the crumb rubber proportion was increased from 0 % to 45 %. However, it is worth mentioning that the optimum incorporation of 45 % crumb rubber in lightweight foamed concrete enhanced the thermal insulating performance by lowering the heat conductivity of the concrete from 1.1863 W.K<jats:sup>−1</jats:sup>m<jats:sup>−</jats:sup> to 0.9733 W.K<jats:sup>−1</jats:sup>m<jats:sup>−1</jats:sup>.</jats:p>