Building Research Establishment

Wallette tests on brickwork show that the relationship between strength and thickness does not follow the square-law implicitly assumed by BS5628:Part 1. Finite Element analysis of various bonds shows that the stress distribution in the region of a bed-joint near to a perpend is so highly non-linear that section-modulus methods for calculating strength may be inaccurate, even as a first approximation. Wallette tests show a thickness effect under horizontal bending very close to that observed in wall tests under vertical bending.