Decision-making for the efficient life cycle management of structures

Abstract

Structures made of structural concrete are designed to withstand different time-dependent or time-independent influences during their expected service lifetime. Most of these influences can be considered in a sufficient manner by mathematical and statistical approaches, while some do appear combined with certain structural, environmental, and material boundary conditions. These can, in most cases, not be foreseen, verified or they change during the lifecycle of a concrete structure. It is therefore obligatory to rely on an efficient conservation strategy for each structure to ensure its safety and overall economic efficiency. For this purpose, the fib Model Code for Concrete Structures 2010 already suggests a general workflow to follow a predefined or provisional conservation strategy and condition control procedure. These existing proposals are yet of very general nature and disclaim practical decision-making rules to survey and assess existing structures as part of a condition-based conservation strategy. In this contribution, the main decision-making options at an early stage of a construction's life cycle management are pointed out, considering their importance for a structure's time-dependent performance and their relation to continuative decisions for conservation management. Proposals for the implementation of practical advice for condition-based conservation strategies in international guidelines are made.