| Popis: |
lightweight concrete (LWC) can be considered as a structural material with unique characteristics such as reduced thermal insulation and low density. However, it consumes huge amount of artificial lightweight aggregates (LWA). Artificial LWA can be manufactured using sintering method or cold-bonded technique. Spite sintering method is more common due to low density of the produced LWA with appropriate mechanical characteristics, it has some economic and environmental drawbacks. Contrarily, cold-bonded technique has environmental and economic benefits due to potential lower energy consumption compared to sintering method. Nevertheless, its application still limited due to low mechanical properties as well as high density of the produced aggregate. This research presents a new method of producing sustainable core-shell artificial lightweight aggregate by using cold-bonded method. To minimize the aggregate density, expanded perlite particles with very low density was encapsulated in a cover layer made of powdered perlite, fly ash and cement. To improve mechanical characteristics of the produced aggregates, surface treatment using a mixture of microsilica and cement was applied. To compare the performance with sintered aggregates (expanded clay), several LWC mixes were prepared and tested. Mechanical properties, thermal conductivity as well as durability of LWC were measured. Scanning Electron Microscopy measurements were conducted to examine aggregate-cement matrix transition zone. The experimental results revealed that the performance of cold-bonded LWA is comparable with sintered LWA. Moreover, LWA with dry density in the range of 1200-1500 kg/m³ and compressive strength of 18-25 MPa was developed using cold-bonded LWA |
