Effect of mixing conditions on the density, morphology, thermal and mechanical properties of mineral foam. (15th July 2022)

• Record Type: Journal Article
• Authors: Mazian, Brahim; Wirquin, Eric; Aguibi, Kawther; Martin, Patrick; Chaveriat, Ludovic; Dubois, Vincent
• Is Part Of: Journal of building engineering. Volume 52(2022)
• Publication Date: 2022-07-15
• Subjects: Mineral foam -- Mixing conditions -- Gypsum -- Flax shives -- Density -- Thermal conductivity -- Mechanical properties; Building -- Periodicals; 690.05
• DOI: 10.1016/j.jobe.2022.104410
• Languages: English
• ISSNs: 2352-7102

Abstract

Abstract: Mineral foam concretes are classified as lightweight concretes, which are characterized by the presence of air voids in the materials due to the use of a suitable foaming agent. Their physical and mechanical properties are strongly governed by microstructural properties, which depend on several factors such as foam quantity, water/binder ratio (W/B), and the mixing process. In this study, mineral foams were prepared with a mixed foaming method. Gypsum is used as a binder, flax shives as vegetative aggregates, and Betomouss as the foaming agent (sodium lauryl ether sulfate as the main tensioactive molecule). The impact of mixing conditions (stirring rate, stirring time, and W/B ratio) on the performances of foams is investigated. The results show that varying these mixing conditions will induce high variation of foam performances at the fresh and hardened states. Furthermore, increasing the stirring rate and stirring time generates an increase of the air-void system, finally causing materials to decrease foam density. Consequently, this entails an improvement in thermal conductivity and a reduction of mechanical properties. In addition, increasing the W/B ratio leads to an increase in spreadability, density, and mechanical properties. In contrast, foams with a low W/B ratio have the best thermal properties. Highlights: Mixing conditions (stirring rate, stirring time, and W/B ratio) of flax mineral foam are investigated. Increasing the mixing rate and time induces an enhancement in thermal conductivity and a reduction of mechanical properties. Increasing the W/B ratio leads to an increase in density and mechanical properties. Flax mineral foams with a low W/B ratio exhibit the best thermal properties.