Thermal conductivity of structural lightweight aggregate concrete

Abstract

This paper characterises the thermal conductivity of structural lightweight aggregate concrete with strength classes ranging from LC12/13 to LC55/60 and density classes from D1·6 to D2·0. The thermal conductivity of concrete is assessed by a transient test method, taking into account different types of lightweight aggregate and binder, as well as different water/binder ratios. The influence of the concrete constituents on its thermal conductivity is analysed and relations between this thermal property and both the density and water content of concrete are established. It is shown that the thermal conductivity of structural lightweight aggregate concrete can be half that of normal weight concrete of similar composition. A high exponential correlation between thermal conductivity and density of concrete is achieved. On average, thermal conductivity decreases about 0·6% per each 1% increment in aggregate porosity, 8·3% per each 50 l/m3 increment in coarse aggregate volume and 3–9% per each reduction of 1% by weight in water content.

Contribution of structural lightweight aggregate concrete to the reduction of thermal bridging effect in buildings

“…According to the supplier, the measurement accuracy in a range between 0.7 and 6 W/m K is 10% for k, 15% + 1 Â 10 3 J/m 3 K for c q and 1°C for T mean . This method was also used by Real et al [20] on a more extensive study on the thermal conductivity of these and other concrete mixtures and also by Oktay et al [31].…”

“…Taking into account the most usual SLWAC produced with different types of aggregate and binder, as well as different w/b ratios, Real et al [20] reported thermal conductivities 40-53% lower in SLWAC than in NWC of equal composition. The authors found an average reduction of 0.6% in thermal conductivity per 1% increment in aggregate porosity.…”

Structural Behavior of Durable Composite Sandwich Panels with High Performance Expanded Polystyrene Concrete

“…The strength of EPS concrete increased with increasing concrete density and decreasing EPS volume fractions (Chen and Fang 2011). The thermal resistance of EPS concrete can also increase with an increase of EPS volume fractions, due to the decreased density (Schackow et al 2014;Real et al 2016). To evaluate optimized HPEPC as a core element in a sandwich panel, the mechanical properties of HPEPC, according to the replacement ratio of UHPC and EPS in a unit volume, were investigated.…”

Lightweight Concrete Made With Waste Expanded Polypropylene-Based Aggregate and Synthetic Coagulated Amorphous Silica

“…The thermal parameters of concrete depend on the thermal characteristics of its phases, in particular the paste and aggregates. Therefore, as aggregates usually constitute about 70 -80 % of the concrete's volume, the incorporation of aggregates with low thermal conductivity might contribute to a significant increase in the thermal insulation capability of concrete [39,40]. The content of EPP particles with advantageous thermal parameters led to the substantial decrease in the thermal conductivity of the developed lightweight concrete.…”