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• Physical salt attack (PSA) is a key damage mechanism of concrete in salt-bearing environments. • The current paper presents a case study analyzing the condition of repaired concrete piles in 47-year-old administrative building. • Deterioration of the concrete piles was observed above the ground level and repair zones. • Thermal, mineralogical and microscopy analyses showed that the underlying mechanism of damage was PSA. • The repair concrete could not stop the progress of PSA on the concrete above it. • Recommendations for future repair strategies are made. Physical salt attack (PSA) is a key damage mechanism of concrete in salt-bearing environments. Multiple case studies were reported throughout literature on PSA of concrete; yet, without any case on the performance of repaired concrete elements. The current paper presents a case study analyzing the condition of repaired concrete piles in 47-year-old administrative building in Winnipeg, MB, Canada, after 22 years from repair works. Deterioration of the concrete piles was visually observed above the ground level and repair zones, in the form of scaling, crumbling and reduction of cross section. In addition to fluid transport and pore structural features tests, mineralogical, thermal and microscopy analyses were performed on concrete chunks/cores extracted from the piles to elucidate the underlying mechanisms of damage. The repair concrete was capable of mitigating chemical and physical sulfate attacks; however, it could not stop the progress of PSA on the concrete above it, urging for careful design of repair strategies for elements subjected to PSA. Recommendations for future repair in this case are also presented. [ABSTRACT FROM AUTHOR]

Abstract: An extensive research project is currently being carried out at the University of Manitoba, Canada, involving the development of glass fiber-reinforced polymer (GFRP) wind turbine towers. The towers consist of multi-cell segments, each segment constructed from eight filament wound cells jointed together with resin applied over their interface. The present paper mainly addresses the static and dynamic characteristics, such as failure static loads, modes of failure, fundamental frequencies and periods of such segmented composite towers. Both experimental and numerical results are presented. The experimental investigation involved the testing of two jointed scaled towers. These specimens had a total height of 4.88-m (16-ft) and were tested as cantilevers under static and dynamic loading. The testing was conducted at the W.R. McQuade Structural Engineering Laboratory of the University of Manitoba. Finally, finite element models were developed to analyze the structural behavior, static and dynamic, of single and multi-cell composite segments and towers. The results from the finite element models under static loading were validated through comparison with the experimental results. [Copyright &y& Elsevier]