Approach and Description of Test Apparatus, Specimen, and Methods

Approach

The fault tolerance of simulated vertical and horizontal panel joints was as­sessed in a laboratory study in which the degree of watertightness of defective joints was determined by subjecting the joints to a range of simulated wind – driven rain loads, loads that were consistent with those that might be found atop tall buildings in a severe storm event. The joints were 20 mm wide and consisted of a one-component polyurethane product and closed cell backer rod. Small deficiencies (cracks), ranging in size between 2 and 16 mm in length, were purposely introduced in the jointing product, thus permitting water to pass through these openings. The joint was extended up to a maximum of 10 % of joint width so that the nature and size of the crack could be varied. Conse­quently, joints with cracks of varying length and size were subjected to water spray rates ranging between 1.6 and 6 L/(min-m2) and pressures of up to 2 kPa. The watertightness tests were carried out using a purposely developed test apparatus described in detail in the subsequent section.