DEVELOPMENT OF GRADING RULES FOR SCAFFOLD BOARDS

摘要

A programme of work has been completed for the UK Health and Safety Executive (HSE) concerned with the development of visual and machine grading rules for 38 x 225 mm scaffold boards spanning either 1.2m or 1.5m between supports. Both the machine and visual grading rules, reported in full elsewhere, were derived from grading measurements and bending tests on the same set of 300 boards, thereby giving the opportunity for a direct comparison of the effectiveness of the strength-indicating parameters underpinning the two methods of grading. Flatwise modulus of elasticity (FMOE), as measured by flatwise bending machines, was found to be far more accurate in predicting bending strength than any of the visual defect measures (or combinations thereof), with knot measures proving to be a poor indicator of bending strength.