A critical evaluation of salt weathering impacts on building materials at Jazirat al Hamra, UAE

Sarah-Jane Bates
Department of Geography, Oxford Brookes University
August 2010

Abstract

Salt weathering results in the breakdown of surface materials and is common in dryland areas. This paper investigates the degree of damage to buildings in Jazirat al Hamra, UAE, which is located on the coast and lies between two sabkhas. The town is one of many sites along the Ras al-Khaimah coastline that have current construction projects with the prospect of further developments. It would be highly beneficial for the construction industry to have a better understanding of how detrimental salt weathering mechanisms such as crystallisation and salt efflorscence can be to modern building materials such as concrete. Salinity values from sediments and observations of damage to structures (of different ages) were recorded along four transects. The transects were oriented to cover the town in all directions to take into account the effects of aspect. This data enabled salinity ranges and building age to be mapped in zones. This enabled analyses of location, climate, aspect and wind influences on salinity levels and building ages according to construction materials. There was a strong correlation between damage, salinity levels and location as well as the beach and sabkha areas being strongly affected. The location of the different ages of buildings were established due to the gradual growth of the town, and the salinity values were affected by the materials used. Modern porous building materials such as Portland cement contained a high content of sodium chloride. The older materials (e.g. bioclastic limestone) have low porosity and better cohesion compared to bricks and cement and this was indicated by the differences in damage levels observed between the ages. The prevailing winds (NNW) appeared to have a greater influence on the results than did aspect. Some damage to structures is shown to be unavoidable and therefore effective preventive practices should be included in all development designs in this location.

Keywords

sodium chloride, sabkha, Portland cement, calcarenites, crystallisation, capillary action

A Critical Evaluation of Salt Weathering Impacts on Building Materials at Jazirat al Hamra, UAE by Sarah-Jane Bates is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.

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Based on a work at geoverse.brookes.ac.uk.

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