Abstract
Proceedings of the 12th North American Masonry Conference in Boulder, Colorado, May 17-20th, 2015. It is believed that one of the causes for unacceptably high death toll in the 2010 Haiti earthquake was due to use of low-strength hollow concrete blocks for masonry construction. After the earthquake, a team of BCIT faculty and students started to work on developing a low-cost nondestructive testing device for strength evaluation of concrete blocks which could be used in Haiti and other countries. The concept is based on the relationship between the compressive strength and the corresponding resonant frequency determined when a block is subjected to a mild impact. A simple block mould procured from Haiti was used to manufacture units with varying mix proportions typical of low-to medium-strength concrete blocks. In total, more than 70 concrete blocks and companion cylinders were made using13 different mix proportions to determine the compressive strength and other mechanical properties.,Conference paper,Published.