Development of a thermally improved hollow concrete block

Abstract

The paper is focused on the comparison of the compression strength and thermal insulation of improved prototypes of hollow concrete building blocks to traditional local building blocks, with the aim of developing a new product for the local market that meets the demand for better insulated buildings. The building blocks under test are hollow concrete blocks (HCBs) manufactured by a local company. The heat flow meter method and infrared method techniques are applied to obtain values of the thermal conductivity of the respective HCBs being tested. Dimensions and weight of these blocks have been recorded and compression testing carried out. The correlation between thermal conductivities and compression strengths of the standard and prototype HCBs shall provide useful information on the thermo-physical behaviour of these building elements. The paper reports on the actual setup of the insitu test cells, followed by the description of the material characterisation, the thermal testing methodologies developed and the compression and dimensional testing carried out. The aim is to succeed in obtaining an innovative block with an improved U-value of at least 10% over existing standard local HCBs without reducing the standard minimum characteristic compressive strength of 7.5 N/mm2.