Durability of marble cladding - A comprehensive literature review

Natural stone has been used for centuries as building material. In historical time it was mainly used as load bearing elements, but within the past 50 years a new processing technique has made it commercially feasible to produce and use thin facade cladding. Unfortunately, a number of marble facades on buildings in both Europe and elsewhere have had serious problems with deterioration of the stone material. The TEAM (TEAM = TEsting and Assessment of Marble and limestone) project consortium represents nine European countries and comprises 16 partners, representing stone producers and trade associations, testing laboratories, standardization and certificate bodies, consultants, building owners and caretakers and producers of fixing and repair systems. The project had a budget of approximately 5 million dollars and was partly funded by the European Commission under the contract no. G5RD-CT-2000-00233. Two of the main objectives in the TEAM project were: - To understand and explain the mechanisms of the expansion, bowing, and loss of strength leading to degradation of marble and limestone clad facades. - To prevent the use of deleterious marble and limestone by introducing a draft for new European standards. This paper presents some of the important conclusions drawn from a literature review carried out within the TEAM project-and was based on an extensive review of literature on marble and limestone deterioration dating from the late 1800s to 2006 and the results of the TEAM project. The comprehensive information from more than 70 selected literature references is reviewed and discussed in order to describe the present knowledge on the causes and mechanisms responsible for the bowing and strength loss of thin marble cladding. In the following, the literature and TEAM findings are grouped under a number of headings proposed to explain observations. Thus, the information from the literature is compared and supplemented with the results from the TEAM project in order to present a good overview of the existing, most relevant, knowledge in the field. The literature review reveals that only few researchers have examined the durability problem from a broad perspective. In addition, no conclusive answer about the mechanisms and influencing factors can be given. The TEAM project has made it possible to identify several of the key influencing factors in marble degradation, the relative importance of various factors, and to gain a deeper understanding of the mechanisms involved.