The summary of the related results is tabulated in Table 1. The average compressive strengthwas determined to be 10.9 MPa with a coefficient of variation of 6.4%, neglecting the result of the second prism. The second prism failed prematurely due to the unevenness of the upper loading surface, where a crack initiated at early stage of loading and caused the failure.The Young’s modulusof the prisms is also determined to be 6.0 GPa based on a secant line between 5 and 33% of average ultimate load. CSA (2004a)specifies E, using 850(fm ) , equal to9.2 GPa, which overestimates the reported value. Typical splitting of the concrete blocks was observed as the dominant mode of failure initiated by cone and shear cracks. Previous studies has attested that the properties of the grout are of the major factors,affecting the failure of grouted concrete masonry, which may occur even at lower stress levels compared to ungrouted concrete masonry (Dhanasekar and Shrive 2002).
|
