Strength Enhancement and Cost Analysis for Lightweight Foamed Concrete in Residential Buildings

This study presents a primary batch of results for an ongoing extensive experimental program related to protein based foamed concrete. Compressive strength is herein investigated as a function of dry density, water content, curing conditions, cement type and, most importantly, foaming agents (employed in the cement paste). Structural Foamed Concrete (SFC) was investigated using a fixed water/cement ratio, CEM I-52.5 N cement, wet-burlap (23 ± 3°C) curing conditions, variable polypropylene fiber content (calculated as a percentage of cement content). Initially, three different foaming protein-based agents were utilized/tested, prior to selecting the agent yielding the highest concrete compressive strength; the latter agent continued as a fixed parameter in the current investigation. This experimental study comprises ninety six (96) foamed concrete specimens with a dry density ranging from 1500 to 1600 kg/m3. The different polypropylene fiber percentages were investigated to enhance the compressive and tensile strength/properties. Results showed that the optimal polypropylene fiber – cement content based (by weight) - dose of 0.3% yields a 32% increase and 27% increase for compressive and tensile strength, respectively. Furthermore, on utilizing the outcomes of the material testing program – for a hypothetical cost analysis study related to a seven-storey building of 400 m2 footprint – a 3 % construction cost reduction is obtained; noting that significant energy savings are anticipated on using foamcrete for slab elements.