Characteristics of Construction Materials: Thermal Expansion and Cooling Behaviours

Abstract

Thermal expansion has been an issue that led to multiple challenges in fields such as transport and construction for many years. Accounting for this is an essential component of selection and usage of many materials, with the degree of uniformity to which materials expand is a centrepiece in designing products. The usage of a heat visualisation cameras allows for accurate mapping of the distribution of heat within a material and identify the uniformity of cooling and suggest the presence of uneven thermal expansions, the source of thermal stresses. Experimental testing allowed for the modelling and analysis of isotropic and anisotropic expansion, whereby wood was found to have the highest coefficient of thermal expansion (⍺), indicating that when exposed to temperature variations, the change in atomic length was the largest in this material. However, experimental and theoretical ⍺ values had significant discrepancy, pointing to inaccuracy due to hygroscopic behaviour of samples and other errors. Material choice for industrial and construction applications is directly dependent on the thermal characteristics and behaviour of the material. The experiment found that Wood had the highest heat retention rate, therefore useful for insulation and structural applications. Further, the fibreboard had the lowest retention and highest rate of cooling, indicating its usefulness in rapid cooling situations and temperature stabilisation