The effect of fly ash and pine tree resin on thermo-mechanical properties of concretes with expanded clay aggregates

We used expanded clay (EC) and cement, fly ash (FA), and pine tree resin as binders instead of conventional aggregate to produce low-density construction material. The EC ratios were 10 %, 20 %, 30 %, 40 %, and 50 %. The FA ratios were 10 %, 20 %, and 30 %. The pine tree resin was 1% of the total volume. The samples were dried for 28 days at room temperature, and then measurements were carried out. We produced 48 samples divided into four groups: no additive (Group 1), FA added (Group 2), resin added (Group 3), and FA + resin added (Group 4). Thermal and mechanical tests were performed to determine where in buildings the low-density construction material could be used. When EC rate increased from 0 % to 50 %, the thermal conductivity coefficient and compressive strength decreased by 55.4 % and 35.1 % only with the effect of the EC aggregate; 13.0–13.69 % with the effect of FA only, 8.4–15.6 % and iii) 17.6–21.86 % and 58.6−17.13% by the effect of FA & resin. The lowest thermal conductivity coefficient was 0.168 W/mK. The highest compressive strength was 24.68 MPa. All samples had a water absorption rate lower than 30 %.