Search Results (4)

The purpose of this study was to evaluate the moisture and flammability characteristics of lightweight concrete with different aggregates and different amounts of cement according to different criteria. The moisture properties of the specimens were evaluated by the coefficient of water absorption due to capillary action, short-term water absorption, and water vapour permeability. Short-term water absorption correlated with the density of the specimens, and capillary absorption was evaluated depending on the soaking time, amount of cement, and type of lightweight aggregate. The values of the water vapour diffusion resistance factor were estimated based on the amount of cement, the type of lightweight aggregate, the density, and the porosity. The porosity correlated with the amount of cement and the type of lightweight aggregate. The flammability properties of concrete with lightweight aggregate were evaluated by several methods, such as the single flame source test, the single burning item test, and the non-combustibility test. After assessing the flammability characteristics, a structure analysis of the samples was specifically performed to assess the processes that occur during the combustion of lightweight concrete. It was found that short-term water absorption depended mainly on the density, capillary absorption on the amount of cement, and the water vapour diffusion resistance factor, flammability, and thermal stability of lightweight concrete on the type of granules. Full article

India is in need of rapid construction technology with sustainability and environmentally friendly aspects. Prefabrication is a well-known technique that lowers carbon emissions and reduces environmental impacts. Life cycle assessment (LCA) evaluates these impacts of developed product/process. A new-age construction product was designed from a locally available agro-industrial waste called co-fired ash (CFA). Expanded polystyrene beads, fly ash, and crushed sand were also used in designing lightweight (LW) sustainable prefabricated panels. The effect of incorporating sustainable alternates into the mix designs is to be studied. An experimental small-scale model house was erected and LCA for the same was carried out with cradle-to-site approach. Based on the inventory, the environmental impact was assessed for four different indicators: acidification potential (AP), eutrophication potential (EP), global warming potential (GWP), and ozone depletion potential (ODP) were evaluated. Carbon emissions of the respective CFA-based concrete and LW prefabricated mix were found to be 0.162 kgCO₂e/kg and 0.268 kgCO₂e/kg, respectively. The impact of energy required during production, transport, and indirect emissions were found to contribute 3%, 3%, and 94%, respectively, to the proposed prefabricated system. Comprehensively, the phase involving mixing of LW mix contributed majorly towards all the impact indicators followed by mould preparation and material transport. The presented data helps the academia to quantify and recognise the possibilities to enhance their products’ performance. Full article

This paper describes the production and performance characteristics of lightweight concrete (LWC) made from porous aggregates, such as expanded glass (EG), made from glass waste, and crushed expanded polystyrene waste (CEPW), obtained by crushing packaging waste from household appliances and ordinary Portland cement (OPC). During the study, the LWC density, thermal conductivity, compressive strength, bending strength, water absorption, deformations, composite structure, and freeze–thaw resistance were evaluated. By changing the amount of OPC and replacing part of the EG with CEPW, it was possible to reduce the thermal conductivity from 0.0977 to 0.0720 W/(mK). The presence of CEPW did not degrade compressive and bending strength or long-term water absorption of LWC. The influence of the amount of porous aggregates and OPC on the resistance to freezing and thawing was investigated by two methods. In one case, the freezing resistance was studied by the method of one-sided freezing of LWC structural indicators and, in the other case, the freezing resistance was determined by the decrease in compressive strength after 25, 100, and 200 freeze–thaw cycles. By modifying the structure with CEPW aggregate the durability of LWC products was increased and deformations were decreased. Full article

The high demand for natural resources and increased industrial activity is driving the construction sector to search for new, more environmentally friendly materials. This research aims to analyse plaster mortars with the incorporation of construction and demolition waste (CDW) to move towards a more sustainable building sector. Three types of aggregates (natural, recycled concrete and recycled from ceramic walls) and two types of insulation waste (expanded polystyrene with graphite and mineral wool) have been added to the plaster matrix to evaluate its mechanical and physical properties and its suitability in the elaboration of prefabricated materials. The results show how plaster mortars made with recycled aggregates have higher mechanical resistance than conventional plaster without incorporating sand. The incorporation of crushed mineral wool residues improves the flexural strength of plaster mortars and their application in the execution of prefabricated panels. Likewise, the expanded polystyrene residues reduce the final density of mortars, improving their behaviour against water absorption and reducing the final thermal conductivity of plaster material. Full article