Discussion of ?Behaviour of a foam mixture as a lightweight construction material? [Int J of Geosynth and Ground Eng (2021) 7(3), 51]

Abstract

The Discussers read the Authors’ paper with interest, having recently published findings on the geotechnical behaviour/properties of clayey sand–expanded polystyrene (EPS) beads mixtures [1]. The Authors purport a ‘new’ cement-treated sand–EPS beads mixture for use as lightweight fill in ground engineering applications, although the concept is not really new, with major research efforts [2,3,4,5,6,7] already reporting on the geotechnical properties of these cement-treated mixtures. The Authors’ geotechnical laboratory investigation for sand–EPS beads mixtures amended with 7–10% (by weight) normal Portland cement (NPC) is a welcome addition to this research literature. The Discussers note that apart from some inconsistencies/weaknesses mostly related to the Authors’ consolidated-undrained (CU) shearbox tests, as elaborated in the next paragraph, the results of the index properties, compaction, unconfined compression and California bearing ratio (CBR) tests presented in the Authors’ paper are in general agreement with those reported for cement-treated sand–EPS beads mixtures by Miao et al. [6, 7].