Managing Corrosion & Durability

National and international code based deterministic and full probabilistic modelling to describe reliability of various Australasian structures
Frank Papworth

This talk provides some background on how the fib 34 chloride and carbonation models can be used in full probabilistic and deterministic modes. Although deterministic analyses are commonly undertaken with ‘conservative’ input values the actual reliability of the outcomes is not known. This knowledge is only available if full probabilistic models are transferred to semi-probabilistic models (partial safety factor models, PSF-models). PSF-models can be utilized in a deterministic mode. The paper outlines some difficulties associated with full probabilistic on the one hand and deterministic modelling on the other and gives information on the input variables. It also provides analysis on various structures as examples of their application.

Challenges in Durability Design of Infrastructure Projects
Radhe Khatri

Designing bridges, tunnels, culverts and other infrastructures for 100 years of life can be a challenging task. Often there is a limited understanding of how the severity of the environment, and also the micro-environment may change with time. As concrete has changed with time, it can be difficult to predict its long-term performance based on the past performance. These, and other problems that a durability designer may face will be discussed in this presentation.

Durability Assessment and Design for 100 year design life in Aggressive Environments – Banora Point Pacific Highway Upgrade
Gary Kao

The Banora Point Upgrade Alliance (BPA) project involves an upgrade of the 2.5 kilometer length of Pacific Highway through Banora Point, in northern NSW.  The design life of major structures associated with the project such as bridges, culverts, retaining walls and inaccessible drainage structures is 100 years. Durability issues identified as relevant for all major concrete structures of concrete within the BPA project environment included 1) Acid sulphate soil degradation & potential acid sulphate soil; 2) Chloride-induced corrosion from Lake Kimberly Canal; 3) Carbonation-induced corrosion; 4) Sulphate attack; and 6) Delayed ettringite formation. This paper describes the methodology adopted in the durability design and the specification of concrete structures to achieve 100 years design life