Evaluation of thermal conductivity and sound absorption coefficient of cement and alkali activated concrete for energy efficient sustainable development

Abstract

The thermal conductivity (TC) and the sound absorption coefficient (SAC) are the most important factors which can make the living zone, habitable area comfortable. Energy efficiency of the buildings greatly depend on these factors. Reduction in loss of heat and sound energy make the buildings energy efficient. Hence, it is important to determine the TC and the SAC of concretes in proper manner. There are several methods that can be used to determine the thermal conductivity and the acoustic properties of materials like concrete. In the present investigation, an attempt has been made to enlighten and determine the changes in thermal conductivity (TC) and the sound / acoustic absorption coefficient (SAC) of Cement Concrete (PCC) and Alkali Activated Concrete (AAC) with different target strength in accordance with IS: 456 :2000 and IS: 17452 :2020 given by BIS (Bureau of Indian Standards). The main focus of this study is to prepare different types of concrete which will be suitable and effective for using as the structural concrete maintaining minimum compressive strength of 17.0 Mpa, conforming to ASTM C 330/C 330 M (2014) and ACI 213R03 (2003) for structural light weight aggregate concrete for a curing age of 28 days. In this study average TC values in case of AAC samples are found as 0.843, 0.763 and 0.998 W/mK for M30, M25 and M20 grade concretes respectively. Average TC values in case of PCC sample are found as 1.843, 2.132 and 2.647 W/mK for M30, M25 and M20 grade concretes respectively. In case of PCC, maximum SAC values are found as 0.211, 0.169 and 0.151 for grades M20, M25 and M30 respectively. In case of AAC, maximum SAC values are found as 0.269, 0.223 and 0.219 of grades M20, M25 and M30 respectively. NRC values are obtained as 0.246, 0.266 and 0.288 in case of AAC of grades M20, M25 and M30 respectively. NRC values are obtained as 0.134, 0.131 and 0.116 in case of PCC of grades M20, M25 and M30 respectively. Average density (BD) values in case of ACC for M20, M25 and M30 grade concrete are found as 2167, 2115 and 2092 kg/m3 respectively. In PCC these values are observed as 2395, 2423 and 2477 kg/m3 respectively. The average compressive strength (CS) values in AAC for M20, M25 and M30 grade concrete are found as 20.92, 25.37 and 33.37 Mpa respectively. Similarly, in PCC these values are evaluated as 22.99, 31.31 and 40.95 Mpa respectively.