Experimental Evaluation of Ageing Marine Structures

The objective of this work is to present a review of recently performed experimental tests of large and small scale steel corroded specimens. Four types of tests are discussed here: corrosion deterioration, ultimate strength, tensile strength and fatigue strength material properties. Two large scale specimens, in the form of box girders simulating the midship section of tanker ship where corroded in a natural open sea condition. The corrosion degradation and its distribution around the structural components of the box girders are presented and discussed. The effect of the severity of corrosion degradation on the strength of the corroded steel specimens is experimentally evaluated, where the box girders are tested under four-point loading, producing a constant bending moment along the box girder until collapse. The experimental results of fatigue strength tests of small scale corroded steel specimens, cut from the same corroded box girders, are also presented. Finally, the experimental tensile strength tests are performed using small-scale corroded specimens, cut from the corroded box girders after the ultimate strength test was completed. The test identifies the effect of the degree of degradation to the mechanical properties of the specimens, namely modulus of elasticity, yield stress, tensile strength and total uniform elongation are also presented. The results of the experimental tests, presented here, are highly important and need to be accounted for when linear or nonlinear structural analyses are performed to evaluate the structural capacity of ageing marine structure.