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Summary: A terrestrial laser scanner (TLS) assessment of corrosion and deterioration on an accelerated laboratory specimen, together with a 40‐year‐old seawall, has been undertaken. The assessment studied the potential of a commercial TLS to detect crack initiation and growth and to monitor long‐term deterioration. In concrete structures with ongoing deterioration, the TLS data were able to identify indicators of delaminated concrete, via surface movement over time, as well as concrete loss. Thus, TLS provides a possible technique to monitor deterioration of concrete structures over time without the need for close access. In the accelerated laboratory specimen, the data showed an apparent correlation between measurement uncertainty and crack growth, though no clear evidence of the exact time of crack initiation or crack width could be determined. [ABSTRACT FROM AUTHOR]

Recent studies have shown that when the operation of steel reinforced concrete impressed current cathodic protection systems is halted the steel can remain passive for a period of time. This paper reports a systematic study using both laboratory specimens and a small scale site trial to investigate the factors influencing the occurrence and duration of residual protection using charge densities of 20, 60, 180 and 540 mA/m 2 . Both the laboratory and site specimens demonstrated short term residual protection. The results indicated that the residual protection was dependant on both the duration and charge passed, with longer periods of protection observed on site following a second application of current. [ABSTRACT FROM AUTHOR]

This paper examines the variation in bond strength in corroding specimens, before surface cracks are visible. Reinforced concrete specimens containing 16 mm and 12 mm diameter bars at covers of 1, 2 and 3 times bar diameter, with and without confinement, were subjected to accelerated corrosion. Bond strength is seen to increase during the early stages of corrosion (pre external cracking) for confined bars at all covers and unconfined bars at 3 times cover. However, while 16 mm bars, 1 and 2 times cover showed similar behaviour the 12 mm bars displayed a decrease in bond once corrosion was initiated. [ABSTRACT FROM AUTHOR]

The deterioration of structures due to reinforcement corrosion is a major problem both in Australia and globally. The corrosion of the reinforcement can lead to rust staining, cracking spalling, and eventually structural failure if no remedial action is taken. In order to assess the condition of a structure a visual inspection is often the first step, with any defects noted. Further visual inspection or installation of monitoring equipment may then be made to identify any subsequent deterioration that occurs. These activities can often be time consuming and expensive, both in the undertaking and in the analysis of the data. This paper reports the use of laser scanning technology to monitor the condition and deterioration of reinforced concrete specimens and relate the level and rate of crack growth with a standard visual inspection. [ABSTRACT FROM AUTHOR]

This paper reports the results of an experimental program to investigate the changes in the bond characteristics of deformed mild steel reinforcing due to chloride-induced corrosion. The principal parameters investigated are the cover depth, bar diameter, degree of corrosion, and the surface crack width. The results show a strong relationship between the average surface crack width and the average bond strength; the degree of corrosion does not demonstrate such a clear relationship. The bars with a 1 C/Φ (cover/diameter) show an initial increase in bond strength at the first visible crack; no similar initial increase is observed for the bars with 3 C/Φ. The bottom-cast bars display a higher bond strength with no corrosion, but a similar bond strength is observed for both top- and bottom-cast bars once cracking is observed. [ABSTRACT FROM AUTHOR]

Investigates the effect of corrosion attack on the mechanical properties of embedded reinforcement through physical tests on bars with simulated and real corrosion damage and through a simple numerical model. Possible impairment of structural capacity through loss of bar section and loss of bond between reinforcement and concrete as a result of longitudinal cracking; Suggested guidelines on assessment.