This paper reviews the evidence arising from exposure tests on reinforced concrete members relating to the influence of cracking on corrosion. This evidence gives no reason to conclude that any relationship exists between crack width and corrosion. This result is confirmed by considerations of the chemistry of corrosion of steel in concrete and the physical nature of cracks. However, it is pointed out that the exposure test data currently available are mostly derived from tests of situations that experience shows do not pose any significant corrosion risk. Suggestions are made as to the direction which the search for a more logical approach to design against corrosion might take. A.W. Beeby
Concrete beams reinforced with a single bar of high-tensile high-bond reinforcement were subjected to cycles of fluctuating loads to determine the fatigue resistance under service conditions. J.L. Bannister
This paper considers current information with respect to fatigue in concrete offshore structures and describes the basis of the research currently being undertaken on this subject in the Concrete in the Ocean programme. The mechanism of fatigue behaviour is described in detail, and the problems in obtaining valid test data for corrosion fatigue are highlighted. The research programme described is intended to provide data needed to give confirmation of the current assumptions made in design. The planned research is not exhaustive, and suggestions for future work are given. H.P.J. Taylor and J.V. Sharp
Building on refuse tips Mr. W. A. Gill takes up a subject raised in this column in September 77: I refer to the problem of building on infilled ground raised in the queries and comments by Verulam in the No. 9 issue of The Structural Engineer and comment as follows: A Local Authority faced with the duty of enforcing Building Regulation D3-'the foundations of a building shall safely sustain and transmit to the ground the combined loads etc.' is placed in a difficult position without the benefit of site explorations and tests which they are not empowered to require. Verulam