Improvement of thermal performance of mortars by using heat storage aggregate made with industrial by‐product to reduce cooling load

Abstract

The usage of waste materials as building materials can be an important method to reduce energy consumption and decrease natural resource usage in the construction industry. In this work, phase change materials (PCMs) were incorporated with industrial by-product materials as an aggregate to produce mortars, which can improve the energy efficiency and improve the environment of buildings. Bottom ash (BA), a by-product from coal-fired power plants, was directly impregnated into paraffin, a PCM, to produce a heat storage aggregate (HSA). The raw materials of the HSA production were characterized by X-ray diffraction, scanning electron microscope, and differential scanning calorimeter. The mortar mixes had a water to cement ratio of 1:2 and a sand to cement ratio of 2.5:1. Six mixtures were prepared with different HSA amounts of 0%, 10%, 20%, 30%, 40%, and 50% by volume. The compressive strength, density, and thermal properties of the mortars were investigated. The results and analyses showed that the compressive strength and density of the mortars decreased with increasing HSA amounts. The thermal conductivity of HSA mortars slightly decreased for increasing levels of HSA. In addition, HSA mortars showed a significant increase in time lags when the HSA content increased, up to approximately 165% to 197% higher than that of the control mortars. HSA levels in mortars can play an important role in improving the heat conductance into buildings.bottom ash, heat storage aggregate, paraffin, phase change materials, thermal properties | INTRODUCTIONRecently, energy demand has increased rapidly due to economic growth, and is responsible for decreasing fossil fuel resources in the world. 1 Around 35% of total