Thermal Performance of Structural Lightweight Concrete Composites for Potential Energy Saving

Abstract

Residential consumption dominates the energy expenditure of heating and cooling systems, especially in tropical climates where building envelopes play an important role in energy efficiency. The thermal properties of concrete that are commonly employed as the building envelope material affect directly human comfort in a building. In addressing both the concrete thermal performance and industrial waste issues, this paper experimentally studies the concrete compressive strength and thermal properties used later for comparative energy analysis for human comfort. Four design mixes and a conventional concrete as control specimen are considered utilizing industrial wastes; palm oil fly ash (POFA), lightweight expanded clay aggregate (LECA), oil palm shell (OPS), and quarry dust, as constituents. These mixes are cast for cube compressive strength (to ensure the achievement of structural concrete requirement) and small-scaled wall tests. The measurement of surface temperatures of scaled wall tests is conducted in a polystyrene box to determine the concrete time lag and decrement factor. It is found that the density of concrete governs the compressive strength and that air pockets in the concrete matrix play an essential role as far as the thermal properties are concerned. From the energy analysis, structural lightweight concrete may save approximately 50% of the residential energy consumption.

Thermal Behavior and Energy Efficiency of Modified Concretes in the Tropical Climate: A Systemic Review

“…Several factors affect the concrete thermal conductivity [55]. For instance, the type of aggregate [56,57], the properties of cementitious materials [58][59][60][61][62][63][64][65][66], moisture content [67,68], design buildup [69][70][71][72][73][74], temperature [75,76], concrete density [12,[77][78][79][80], etc.…”

“…In the concrete industry, there are several solutions to reduce the carbon footprint, such as phase-change materials [108][109][110], lightweight concrete [11,12,55,[111][112][113], or cementfree concrete [59,65]. Some of these reduce the carbon footprint through minimising the use of cement since its production contributes much carbon to the environment, while some solutions provide more long-term effects on building performance or services.…”

“…Lightweight concrete is an alternative in achieving both mechanical and functional properties when relating to thermal performance [11,12,55,113]. From non-structural (brick, 5 MPa) to structural uses (17 MPa), the concrete densities can range between 1000 to 1800 or 2000 kg/m 3 for foamed concrete [11,134] or lightweight aggregate concrete.…”

“…where US is the transmission area and (T o − T i ) is the temperature difference between outside and inside the building (8 • C taken from the previous study, [55]).…”

“…The design mix of OPS & 50-QD of [55,135] has been collection from tropical climate conditions and was comp as shown in Figure 2. The mix contained oil palm shells 50% quarry dust as a fine aggregate replacement.…”