Performance characteristics and failure mechanism of structural light-weight vs. normal-weight concrete materials.

摘要

Various aspects of the performance characteristics of light-weight concrete materials made with a ceramic-based coarse light-weight aggregate were investigated and compared with those of normal-weight concrete with similar mix proportion (by volume) and fresh mix properties.;Light-weight concrete materials were, on the average, 40% more permeable than normal-weight concrete materials. Compressive loading up to 40% of the compressive strength increased the average permeability of normal-weight and light-weight concrete by 29% and 8%, respectively, indicating more severe damage in normal-weight concrete under compression.;The microcracking and failure mechanism of light-weight concrete under compression and impact loading is distinguished from that of normal-weight concrete by the lack of microcrack at the aggregate-paste interfaces and reduced intensity of microcracks in light-weight concrete.;Two synthetic fibers with different elastic moduli when used in light-weight and normal-weight concrete produced comparable effects on flexural strength and toughness, but the higher-modulus fiber gave higher impact strengths. Fibers were generally found to be more effective in light-weight concrete than in normal-weight concrete.