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Abstract: This paper presents the results of an experimental program developed to study the feasibility of producing prestressed concrete girders using lightweight concrete. During the experimental campaign, bond tests were performed in push-in (TL bond test) and pull-out (FB bond test) types of specimens. To-scale prestressed concrete elements were produced, implemented, and tested. The variables studied were the type of concrete, the test age, and the delayed effects of bond. The TL bond test allowed the behavior of the transfer length to be characterized, governed by the Hoyer effect. Equations have been calibrated to identify the upper and lower transfer lengths using the experimental results of this trial. The proposed equations delimit the safety boundaries of the experimental transfer length values obtained in the experiments performed on the beams. The results obtained in the experimental phase discourage the use of the studied lightweight concrete for producing pre-tensioned concrete elements. [Copyright &y& Elsevier]

Abstract: This paper presents a spatial time-dependent reliability analysis to predict the likelihood and extent of cracking for reinforced concrete structures exposed to chloride ion attack. A reinforced concrete surface is discretised into a large number of smaller elements and random field methods used to simulate the variability of the concrete damage over the entire area. Models predicting corrosion initiation and propagation, crack initiation and crack growth are used to track the evolution of the corrosion process for each element and thus allow the extent of damage as a function of time to be determined. A range of durability design specifications are investigated and maintenance thresholds are defined as being reached when a specified proportion of the bridge deck is damaged, say 1%. This will enable the minimum time to first repair to be estimated. The results provide a comparative tool to assist designers in selecting design specifications and possible maintenance regimes to achieve an optimal outcome in terms of service-life and life-cycle cost of the structure. [Copyright &y& Elsevier]

Abstract: The paper gives the results of an analytical method proposed to predict the load deflection behaviour of partially restrained slab strips. The effect of deflection prior to yield line load on the development of compressive membrane forces was incorporated in the theoretical analysis. An experimental programme was designed to cast and test ten partially restrained slab strips with different edge rigidity. A comparison has been made between the results of the proposed and one of the other methods available in the literature. The results indicate that the proposed method can predict the load deflection behaviour satisfactorily. A parametric study has been made on the load enhancement beyond yield line load and the results are presented. [Copyright &y& Elsevier]