Fracture and failure analysis of stone cladding on building facades

Kam Tim Chau, J. F. Shao

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

Abstract

Cracking in rock panels on façade walls of commercial buildings worldwide have led to severe safety problems. This long term cracking on the rock panels has been caused by the presence of chemicals in polluted and moisturized air and to repeated solar heating on the surface. This paper examines the sub-critical or corrosive cracking in rock panels containing either pre-existing edge cracks or internal micro-cracks subject to periodic solar surface heating on one side of the panel while the other is kept at constant temperature (air-conditioned). The thermal stress induced stress intensity factors are determined using superposition technique by employing the fundamental point loads solution for an edge crack or a centre crack in a slab, subject to either free or fully constrained end conditions. The initial crack size is assumed as the smallest undetectable micro-cracks pre-existing in the rock panels, while the critical crack size at which rock panel failure may occur is estimated from the bending of a cracked strip under design wind load. Once the daily induced stress intensity factor is higher than the threshold value, sub-critical cracking occurs (Fig. 2). The long term fatigue life of rock panels can then be established in terms of fracture mechanics approach. It was found that the stress intensity factor induced at edge cracks are larger than that at center cracks (for the case that crack lengths are a and 2a for edge and center cracks respectively). For center cracks, thermalcycle- induced stress intensity factor at the tip closer to the heating surface is larger than that farther from the heating surface. Various types of rock and concrete have been studied, including granite, gabbro, basalt, limestone, sandstone, slate, marble, shale, quartzite and concrete. This rational approach based upon fracture mechanics should improve the current state-of-the-art practice of the design of rock panels on façade.
Original languageEnglish
Title of host publication11th International Conference on Fracture 2005, ICF11
Pages2202-2207
Number of pages6
Volume3
Publication statusPublished - 1 Dec 2005
Event11th International Conference on Fracture 2005, ICF11 - Turin, Italy
Duration: 20 Mar 200525 Mar 2005

Conference

Conference11th International Conference on Fracture 2005, ICF11
CountryItaly
CityTurin
Period20/03/0525/03/05

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology

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