Effect of Iron (III) Oxide Powder on Thermal Conductivity and Diffusivity of Lime Mortar.

Francesc Masdeu,Joan Muñoz,Cristian Carmona,Gabriel Horrach

doi:10.3390/ma14040998

Abstract

One of the challenges in construction is the improvement of energy efficiency of buildings. Development of construction materials of low thermal conductivity is a straightforward way to improve heat isolating capability of an enclosure. Lime mortar has a number of advantageous and peculiar properties and was widely used until the “irruption” of Portland cement. Currently, lime mortar is still used in restoration of traditional buildings or, according to the urban regulations, in catalogued constructions. The goal of the present study is the improvement of the heat isolating capability of lime mortars. The strategy of this work is the addition of iron (III) oxide powder, which is one of the possible components forming the cements, to a base lime mortar. The reason to choose Fe2O3 was two-fold. The first reason is low thermal conductivity of Fe2O3 compared to lime mortar. The second reason is that the low solubility and small size of iron (III) oxide particles have an effect on the thermal conductivity across the lime particles. The effect of iron (III) oxide powder on the thermal conductivity has been experimentally determined by the hot-box method. It has been found that the insulating capacity and thermal inertia of lime mortar is improved significantly by the addition of Fe2O3 powder, increasing the energy saving of the enclosure.

Highlights

In order to reduce the consumption of energy, great efforts have been devoted in developing low thermal conductivity construction materials and improving the efficiency of materials currently in use [1,3]
It has been found that the insulating capacity and thermal inertia of lime mortar is improved significantly by adding Fe2 O3 powder, increasing the energy saving of the enclosure [26]
Theoretical bulk densities were calculated from the bulk density of calcite (2.71 g/cm3), which is the main component in lime mortar, and iron (III) oxide (5.26 g/cm3) considering their volume fractions for each sample [29]

Summary

Introduction

The increased use of energy from fossil fuels has provoked dramatic climate changes. According to the United Nation Environment Program, the energy consumption of buildings represents nearly 40% of the world global energy [1], and around two-thirds of the energy demand in the residential sector is attributed to heating and cooling [2]. The field of construction can assist to mitigate these effects on global warming by improving the performance of construction materials, e.g., increasing heat insulating capability. In order to reduce the consumption of energy, great efforts have been devoted in developing low thermal conductivity construction materials and improving the efficiency of materials currently in use [1,3]

Objectives

Methods

Results

Conclusion