The Effect of Mixing Technology on the Mechanical and Physical Properties of Foamed Concrete

Abstract

Foamed concrete is defined as a lightweight product made by introducing a foaming agent that generates air bubbles in the cement mortar. The introduced air bubbles reduce the density of the cement mortar, making the foamed concrete lightweight. It is produced according to various mixing parameters depending on the mixing equipment used. This research aims to investigate the impact of mixing technology—represented by mixing speed, mixing duration, and mixing method—on the physical properties of foamed concrete, particularly its dry density, as well as its mechanical properties, specifically its compressive strength. The study establishes mathematical relationships between these factors to identify the optimum mixing technology to produce foamed concrete samples with the lowest possible dry densities while maintaining acceptable compressive strength. Eight mixes were prepared using a cement content of 350 kg/m³, a water-to-cement ratio (W/C) of 0.56, a sand-to-cement ratio (S/C) of 0.25, and a foaming agent -to-cement ratio (F/C) of 0.011. These mixes were used to investigate the effects of mixing speed, mixing duration, and mixing method on the physical and mechanical properties of foamed concrete. The parameter under investigation was varied, while the other parameters were kept constant. Various tests were carried out to determine certain physical and mechanical properties of the foamed concrete, such as wet density, dry density, and compressive strength.At the end of this research, the effects of mixing speed, mixing duration, and mixing method on the dry density and compressive strength of foamed concrete were determined. Empirical mathematical relationships linking these factors were established. In addition, the optimum mixing parameters were identified to produce foamed concrete with the lowest dry density while maintaining an acceptable compressive strength. It was found that the optimum mixing method is the pre-formed foam method, with the optimum mixing speed set at V = 900 RPM and the optimum mixing time set at T = 180 SEC.