Editors: | F. Kongoli, A. G. Mamalis, K. Hokamoto |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2018 |
Pages: | 352 pages |
ISBN: | 978-1-987820-88-1 |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
The quasi-static and dynamic compression and indentation behavior of the autoclaved aerated concretes (AAC), with the average densities of 490, 405, 400, and 180 kg m-3 were determined experimentally. It has been noted that there are only a few studies on dynamic behavior of light-weight concrete in the literature [1-3]. The quasi-static tests were performed at the nominal strain rates of 0.001, 0.01, and 0.1 s-1. The high strain rate tests were conducted using a modified compression type Split Hopkinson Pressure Bar (SHPB) apparatus in the direct impact mode: the striker bar impinged, with an initial velocity, the concrete samples inserted at the end of the incident bar. The velocity of the striker bar in the direct impact tests was 9 and 30 m s-1, corresponding to the strain rates of 500 and 1500 s-1, respectively. The fracture strength of the quasi-statically and dynamically tested samples were further fitted to the Wiebull cumulative distribution function. The cracks initiated at the compression test plate-sample interface and progressed diagonally to the cylindrical tests sample in the quasi-static strain rates. The facture behavior of the lowest density samples were slightly different in that the cells near the upper and lower compression plate were crushed until about major diagonal or lateral cracks form. The crushing in the direct impact tests started from the impact end of the sample and the samples were completely shuttered into many small pieces, featuring enhanced energy absorption at these strain rates. A similar observation was also made previously [3]. The reduction in the Weibull distribution modulus, m, at high strain rates also showed more brittle behavior of the concrete sample. The indention behavior of the compression tested samples showed somewhat similar behavior of increased resistance to the indenter at increasing strain rates. The results clearly indicated the potentials of these materials to be used against the localized impact, while there existed almost no experimental work on these materials.