A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
The Reference Approach to Service Life Design
Abstract Most service life design models, including the Duracrete/fib approach, require the definition of several parameters such as: chloride surface concentration, chloride critical level (that triggers corrosion of steel bars), ageing factor (that determines the decay of chloride diffusion coefficient with time). Several, if not all, of these parameters are very difficult to assess beforehand and have to be established by the designer rather arbitrarily. Several authors have pointed out the enormous sensitivity of the predicted service life to the values adopted for the above mentioned parameters. This fact, confirmed in the paper, generates a large degree of uncertainty or subjectivity in the predicted service life and opens the door to manipulation of the parameters to “get what we want”. The approach proposed in this paper is to take a reference condition that, in principle, should be one corresponding to a “deemed-to-satisfy” case, for instance from the Eurocodes/EN 206-1, on which the service life prediction for the case under consideration is based. With the maximum w/c and minimum cover depth, established for a given exposure condition, it is possible to estimate the expected coefficient of chloride diffusion D0 at 28 days and mean cover depth for 50 years service life. As a result, assuming the elusive parameters discussed above do not change between 50 years and the service life age, it is possible to develop a formula which does not require the explicit input of the parameters. It is considered that this approach may lead to a more robust Service Life design than the current Duracrete/fib approach.
The Reference Approach to Service Life Design
Abstract Most service life design models, including the Duracrete/fib approach, require the definition of several parameters such as: chloride surface concentration, chloride critical level (that triggers corrosion of steel bars), ageing factor (that determines the decay of chloride diffusion coefficient with time). Several, if not all, of these parameters are very difficult to assess beforehand and have to be established by the designer rather arbitrarily. Several authors have pointed out the enormous sensitivity of the predicted service life to the values adopted for the above mentioned parameters. This fact, confirmed in the paper, generates a large degree of uncertainty or subjectivity in the predicted service life and opens the door to manipulation of the parameters to “get what we want”. The approach proposed in this paper is to take a reference condition that, in principle, should be one corresponding to a “deemed-to-satisfy” case, for instance from the Eurocodes/EN 206-1, on which the service life prediction for the case under consideration is based. With the maximum w/c and minimum cover depth, established for a given exposure condition, it is possible to estimate the expected coefficient of chloride diffusion D0 at 28 days and mean cover depth for 50 years service life. As a result, assuming the elusive parameters discussed above do not change between 50 years and the service life age, it is possible to develop a formula which does not require the explicit input of the parameters. It is considered that this approach may lead to a more robust Service Life design than the current Duracrete/fib approach.
The Reference Approach to Service Life Design
Torrent, Roberto (author)
2017-08-06
10 pages
Article/Chapter (Book)
Electronic Resource
English
Defining Reference Service Life: An Open Innovation Approach
| British Library Conference Proceedings | 2005
| Online Contents | 1996
| British Library Online Contents | 1996
| Wiley | 2004
The service life design strategies
| British Library Conference Proceedings | 1999