Mechanical and Thermal Behaviour of Thermal Insulated Cement Mortar With Silica Aerogel

• Main Author: Lee Thin, Tay
• Format: Thesis
• Language: English; English
• Published: UNIMAS 2022
• Subjects: TA Engineering (General). Civil engineering (General)
• Online Access: http://ir.unimas.my/id/eprint/39181/2/Master%20Thesis_Tay%20Lee%20Thin%20-%20cutted.pdf; http://ir.unimas.my/id/eprint/39181/3/Master%20Thesis_Tay%20Lee%20Thin-%20fultext.pdf; http://ir.unimas.my/id/eprint/39181/
• Institution: Universiti Malaysia Sarawak

Cities or towns are having a higher temperature compared to the rural area and it is known as urban heat island (UHI). UHI indirectly induces the rising of indoor temperature. The heat tends to move from outdoor toward indoor by passing through building envelope. Consequently, human indoor discomfort level is increased. As a result, application of thermal insulator to the building envelope has been put in place to address the issue of thermal discomfort. There are various thermal insulators that are available and it is important to have thermal insulators to resist the heat flow from outdoor towards indoor. Conventional thermal insulation materials are mineral wool, EPS, XPS and cork. In the meantime, silica aerogel (SA) is a newly introduced insulation material. Silica aerogel was introduced with thermal insulation criteria where it possesses properties such as, lightweight, high specific surface area, high porosity, low density and high thermal insulation value. Therefore, silica aerogel was studied in this project in the form of powder and mat to produce silica aerogel mortar and silica aerogel sandwiched mortar respectively. The objectives of the study were to determine the mechanical properties and thermal properties of mortar incorporating silica aerogel powder and silica aerogel mat as well as to evaluate the thermal performance of the silica aerogel mortar panel and silica aerogel sandwiched mortar panel. Firstly, the experiment of mechanical properties was conducted to determine the mechanical properties and obtain the optimum ratio for silica aerogel powder mortar. Based on the results, 15% vol. silica aerogel (by replacing sand) was the optimum ratio for the SA powder mortar. Meanwhile, flatwise compressive test and edgewise compressive test were investigated for silica aerogel sandwiched mortar with three different thicknesses (9 mm, 12 mm and 15 mm) and 15 mm core thickness sandwiched mortar achieved highest flatwise compressive strength. Next, all the sandwiched mortar samples and silica aerogel mortar with optimum ratio were further prepared and used for thermal conductivity and thermal resistivity test which were conducted in laboratory, while field testing for thermal performance was carried out in open space under exposure of sunlight. It was concluded that 15% vol. silica aerogel mortar and silica aerogel sandwiched mortars were determined to have lower thermal conductivity than type N mortar (exterior, non-load bearing wall component) and possess better thermal insulation property compared to type N mortar. By replacing concrete block and red clay brick with silica aerogel mortar panel or silica aerogel sandwiched mortar panel, heat flow was expected to reduce and bring least indoor temperature fluctuation, hence maintain indoor thermal comfort level.