Abstract. Aerated concrete is produced by introducing gas into a concrete, the amount dependent upon the requirements for strength. One method to achieve this is by using powdered aluminium which reacts with the calcium hydroxide produced upon hydration of the cement. The aim of the current study was to investigate the influence of the powder content on the mechanical properties of aerated concrete namely; compressive and flexural strengths, modulus of elasticity, density and porosity. The results indicated that an increase in aluminium content caused a decrease in the compressive and tensile strengths. It also produced a decrease in the modulus of elasticity. When the aluminium content increased, the density decreased and the porosity increased.

Pore space, which occupies 60 -90% of the volume in aerated concrete, is important when considering performance. In this paper the properties of density, porosity, capillary suction and water absorption are investigated for aerated concrete produced. Aluminium powder was used with the percentage ranging between 0.25 and 1% by cement weight in order to produce the aerated concrete. Density, porosity and capillary suction tests were carried out after immersion in water for 28 days. The results show that the highest density of aerated concrete was with 0.25% aluminium powder. The porosity values obtained by vacuum saturation were consistently found to be higher than those obtained by soaking which suggests that the soaking method does not access all the pore space. Also, the capillary suction of aerated concrete as assessed by sorptivity was significantly higher than that measured by coefficient of water absorption method. However, both methods show the water absorption of aerated concrete increases with increasing aluminium content.Index Terms-Aerated concrete, density, porosity, water absorption and aluminium powder content.

This investigation aims to improve some of the mechanical properties of concrete such as compressive strength, flexural strength, and modulus of elasticity, by using different percentages of polypropylene fibers, and also studying the durability of concrete for freeze-thaw cycles. the study shows a small increment in compressive strength due to adding fibers which were 28.3% compared with increment in flexural strength which was perfect (about 191%), modulus of elasticity also increased by adding fibers. The durability of concrete against freezing-thaw cycles for all mixes was studied. Fiber-reinforced concrete shows more durability against freezing-thawing cycles and less reduction in strength compared with reference mixes without fibers,21.5% reduction in strength for optimum polypropylene fiber concrete while the reduction in strength for normal concrete was found 54.2% in this study.

Aerated concrete is produced by introducing gas into a concrete which has a low tensile strength. The aim of the current study is to investigate the behaviour of aerated concrete with different Al content under monotonic loads. A finite element (FE) model to produce a more sophisticated explanation of the AC behaviour in compression, is constructed. The results showed that an increase in Al content caused a decrease in the compressive strength, modulus of elasticity and density of aerated concrete. FE outputs hold a close agreement with the experimental values which can be confidently used instead of further potential experimental work. Index Terms-Aerated concrete, aluminium powder, concrete behaviour and finite element.