Assessment of the structural health monitoring of a historic reinforced concrete water tower

Abstract

Degradation of Reinforced Concrete structures exposed to aggressive environment is of major concern in the construction industry. The work presented refers to the thorough assessment of a structure, the Water Tower at the Malta Civil Abattoir, exposed to an aggressive marine environment and its restoration using advanced materials, restoration technologies and monitoring systems. This Water Tower was constructed in the 1930s and is located in the Grand Harbour, close to the coast. It suffered severe degradation due to a coastal exposure. The restoration required a comprehensive approach covering different critical and important stages. The restoration of the structure and use as a Water Tank required an appreciation of the historic structure and relies also on the use of advanced materials which can address the requirements of the structure. The project included the following stages: Advanced appraisal of an industrial heritage structural for conservation, through materials testing, numerical structural modelling and scenario testing to optimise repair and strengthening interventions; Development and then the application of advanced ultra-high performance materials applied for the first time, including ultra-high performance self-healing nano-additive based concrete and carbon textile reinforced high performance concrete for the strengthening of the structure; Development of new techniques for restoration of concrete heritage structures including electro-chemical chloride extraction, re-alkalisation of reinforced concrete, epoxy injection and polymer concrete patch repair with corrosion inhibitors, re-integration of the structure, and an advanced sensor network system for monitoring over time.