Title:
Variable Density Precast Concrete Panel Development
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Publication:
CIA
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DOI:
Date:
2/13/2011
Abstract:
The development of a variable density precast concrete panel system is described that significantly improves the thermal efficiency of concrete buildings by both improved insulation and increased thermal mass. Concrete from a single mix is stratified (defined as controlled segregation under vibration) to produce a lightweight, top layer and a dense, bottom layer. When erected, the panels have the lightweight layer on the outside providing insulation while the inner layer provides structural strength and improves thermal mass. Concrete mixes were stratified using different density aggregates, ensuring the rheology was in the correct range and using moderate levels of vibration. Waste materials such as fly ash, slag and expanded glass were used together with either Portland cement or inorganic polymer cements. Results from laboratory trials are presented showing the rheological, structural, serviceability, and thermal performance of the system. Initial findings suggest that there is significant potential in using variable density concrete in buildings to improve thermal efficiency and comfort. Further testing is currently been undertaken to measure the structural performance, serviceability and durability of variable density concrete.