Confirmation of the suitability of autoclaved aerated concrete panel substrate for mechanically attached waterproof systems and their strengths under high wind loads

Abstract

The reliability of autoclaved aerated concrete (AAC) panels as a substrate for mechanically attached waterproof systems, subjected to the effects of strong winds, required verification. The strengths of fasteners in AAC panels were studied by static and dynamic tensile tests. The most commonly used mechanical and chemical fasteners were tested, and their strengths and AAC fracture modes were observed. Static strength values ranged from 2.0 to 5.0kN. The dynamic strength decreased from 1.5 to 2.2kN. Moreover, we eliminated extensive AAC fracture of the chemical fasteners by innovatively using elastic adhesive instead of the commonly applied epoxy resin.We examined the behavior of complete mechanically attached waterproof systems with such substrates by using a specially designed and produced constant-load-type dynamic-test apparatus. We tested two polyvinyl chloride (PVC) membrane types and two different membrane-to-disc connection methods. The number of repetitions until failure was as high as 100,000, and we recorded fracture modes identical to those occurring on actual roofs under the influence of strong winds.The relationship between the dynamic strengths of the fasteners and complete waterproof systems was presented, and AAC panels were confirmed to be substrates with a sufficient bearing capacity for mechanically attached waterproof systems. A method to determine the maximum fastener spacing was also proposed.