Thermal performance enhancement of hollow brick by agricultural wastes

Abstract

Because agricultural wastes can be used as good building insulation materials due to their huge output, wide distribution, recyclability, and high thermal resistance, they are the better selections to improve the thermal performance of envelopes in rural buildings. The hollow bricks filled-with agricultural wastes were proposed, and six groups of walls were built by hollow bricks filled with different kinds of agricultural wastes, including reed leaves, reed stems, rice shells, rice straws, and wheat stems in order to select the reasonable agricultural wastes. The simple hot-box heat flow meter method was used to measure and calculate the overall heat transfer coefficient of hollow brick walls filled with agricultural wastes. The experimental results showed that the insulation performance of the hollow brick was significantly improved due to filling agricultural wastes. Five agricultural wastes can reduce the overall heat transfer coefficient of hollow-brick walls by 12.7~32.7%. And the rice straws were the best selection to be filled into hollow bricks and they can reduce the overall heat transfer coefficient from 1.59 W/(K·m2) to 1.07 W/(K·m2), which showed that thermal performance of hollow-brick wall was improved by 32.7%. Hollow bricks filled with agricultural wastes can be utilized for future construction renovation in rural areas as insulation materials.