The effect of thermal expansion and contraction in masonry has been simulated using repeated stress cycles. Cylindrical specimens cast from 1:2 NHL3.5 lime mortar were exposed to air at 208° and 65% relative humidity with a CO2 concentration of 400 ppm for 28 and 84 days respectively prior to stress cycling 40 times. Cycling did not influence the peak stress recorded from subsequent destructive compressive testing, however the un-cycled specimens absorbed more energy up to the peak stress, compared with the cycled specimens. Ion-induced electron images of the mortar structure revealed the presence of micro-cracks in the cycled mortars, suggesting the energy absorbing mechanism.
|Number of pages||7|
|Journal||Proceedings of Institution of Civil Engineers, Construction Materials|
|Publication status||Published - 2007|