An investigation on the functional properties of 1600 kg/m3 foamed concrete with calcium stearate

Lim, Yu Tong (2023) An investigation on the functional properties of 1600 kg/m3 foamed concrete with calcium stearate. Final Year Project, UTAR.

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Abstract

As global warming intensifies, the construction industry seeks a substitute for ordinary concrete due to its high dead weight and thermal conductivity. The current trend is using foamed concrete, lightweight concrete with a more strength-to-weight ratio with a density ranging from 300 to 1800 kg/m3 . It decreases dead loads on the structure, manufacture costs, construction labor expenses and shipping costs. In addition, the large number of pores in foamed concrete decreases heat absorption, making the structure suitable for all climates. However, lightweight foamed concrete (LFC) is typically utilised on the exterior of buildings, such as walls and roof slabs, where it is frequently subjected to natural weathering such as rain. Since water is a detriment to the long-term durability of LFC, calcium stearate (CS) is incorporated. CS is a water repellent agent that minimises water penetration into LFC. This study aims to investigate the functional properties of 1600 kg/m3 foamed concrete with calcium stearate. The functional properties including sound absorption and thermal conductivity of foamed concrete were tested and evaluated based on the ASTM standards. Besides, one of the mechanical properties, namely compressive strength was also evaluated in this research. A trial mix was performed to get an optimum water-cement (w/c) ratio and the optimum w/c ratio of 0.58 was obtained and used in the actual mix. Six types of LFC with different shapes and dimensions containing different concentrations of CS were casted and water cured for 7 and 28 days before being tested for their compressive strength, water absorption and functional properties. The dosage of CS added ranged from 0 % - 1.0 % with an interval of 0.2 %. It was found that the presence of CS may reduce the fresh concrete's permeability and water absorption and thus producing low fluidity. Besides, the finding also showed CS dosage only affected overall compressive strength at early ages of LFC. Besides, adding CS may reduce the LFC mix's water absorption until a certain dosage. If an overdose of CS, it may have a negative impact on the LFC mix by limiting its waterproofing performance. Lastly, introducing CS into LFC can enhance sound absorption and thermal resistance.

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