Solutions for Exposed Structural Concrete Bridged Elements for a More Sustainable Concrete Construction in Hot Climates

Abstract

New energy-efficiency regulations have been established and applied in many Gulf countries to improve building energy performance. Thermal bridging reduces the building envelop performance, and this is not a focus of these regulations. This paper investigates the concrete construction of residential housing in hot climates and identifies more sustainable concrete construction methods. Both experimental and numerical methods are used to identify the impact of thermal bridging. Using finite element analysis, the impact of solar radiation on a building’s thermal bridging was analyzed. It is identified as an essential element for accurate modelling of bridging across concrete in a hot climate. The FE model was evaluated against monitored data and assessed using common statistical indicators. The results show that the heat loss across uninsulated cast in situ structural elements is more than double the heat loss across portions of insulated walls. Moreover, neglecting solar radiation on the westerly façade can result in errors of >50%. Additionally, the impact of thermal bridging is increasingly evident when accounting for solar radiation. Modelling studies show that the impact of thermal bridging could be reduced by up to 73% by covering the structural elements with external insulation. Compliance with the various codes of the different Gulf states can be achieved through externally insulating with between 40 and 80 mm, and this is shown to have wide-ranging benefits in enhancing building energy efficiency.

Experimental and Numerical Assessment of the Thermal Bridging Effect in a Reinforced Concrete Corner Pillar

“…Moreover, it is interesting to underline that in Southern Europe, "good practice" insulation with corrected thermal bridges can reduce the space heating demand of a building by around 30% in the winter, but the effects of thermal bridge correction in the summer is practically negligible, because of the limited temperature gradient between indoors and outdoors [15][16][17]. However, in very hot climates such as in the Gulf area, the intense solar radiation hitting the structural elements, especially in the west façades, makes heat gains through thermal bridges not negligible in the summer; covering the exposed structural elements with a layer of insulation of no more than 100 mm can prevent such a negative effect [18]. Finally, the mitigation of thermal bridges is also of crucial importance in the refurbishment of traditional buildings, as pointed out by Cirami et al [19].…”

Experimental Heat Transfer, Sound Insulation and Interior Comfort Parameters Assessment on a Box Double-Skin Façade

“…However, in order to make the most of this potential, state-of-the-art technologies must also be cost-effective in order to be widely adopted. Both opaque and transparent envelopes protect the occupants of the building from adverse weather conditions from the outside [14][15][16][17]. The envelope of a building can be designed from the start with systems that make use of some of the resources available in the outdoor environment (natural light, natural ventilation, etc.)…”