One of the elements of the integral approach of the DARTS-project is the service life design of structures. In an earlier EU-funded research project, entitled DuraCrete, a major step forward has been made in this field. A summary of the project and an overview of available reports are presented here.
DuraCrete
The DuraCrete-project aimed to develop a performance based durability design methodology, based upon realistic and sufficiently accurate environmental and material models capable to predict the behaviour of a concrete structure. The work is based on a design framework in which a/o the probabilistic modelling, limit states and modelling of deterioration mechanisms are formulated.
Physical models for relevant deterioration processes and compliance tests resulting in necessary input data have been chosen. Compliance tests on several concrete compositions have been carried out. Results are quantified statistically, describing basic variables, the type of distribution, the mean, the standard deviation of variation coefficient and a proper definition of the population, leading towards the design format.
The Durability Design Guide is written in a code-like format. However, it must be realised that the guide, in its present form, is not a code and that it is not a part of an existing system of codes like the Eurocodes. Further, the guide has not been submitted to public approval.
In the guide, technical recommendations and general guidelines have been drawn up for durability design and redesign of reinforced concrete structures. The guideline for durability design is based on the LRFD approach (Load Resistance Factor Design). The LRFD approach is a so-called level 1 approach where all variables are represented by deterministic values and where the reliability of the structure with respect to a given event is assured by applying partial safety factors for the load and resistance variables. The safety factors are developed on the basis of reliability analysis such that a given service life can be assured with an accepted level of reliability.
The guide is to a large extent based on probabilistic analysis because this methodology offers a consistent basis for updating the reliability of the structure using information from inspections and measurements.
General information and to order DuraCrete reports:
CUR, Centre for Civil Engineering Research and Codes
paulien.brandhorst@cur.nl
DuraCrete Reports
DuraCrete reports are available through CUR
R0 Probabilistic Methods for Durability Design 85 pp, January 1999, ISBN 90 376 0424 2
R1 Design Framework
165 pp, March 1997, ISBN 90 376 0390 4
R2a Chloride Induced Corrosion – Mini Project
40 pp, January 1997, ISBN 90 376 0434 x
R2b Probabilistic Design of Concrete Pavements – Mini Project
56 pp, May 2000, ISBN 90 376 0391 2
R3 Models for Environmental Actions on Concrete Structures
273 pp, March 1999, ISBN 90 376 0400 5
R4-5 Modelling of Degradation
174 pp, December 1998, ISBN 90 376 0444 7
R6 Compliance Tests. State-of-the-Art
130 pp, September 1997, ISBN 90 376 0454 4
R7 Compliance Testing for Probabilistic Design Purposes
Evaluaton Report
83 pp, August 1998, ISBN 90 376 0464 1
R8 Compliance Testing for Probabilistic Design Purposes
105 pp, March 1999, ISBN 90 376 0420 x
R9 Statistical Quantification of the Variables in the Limit State Functions
130 pp, January 2000, ISBN 90 376 0374 2
R10 Benchmarking of the Conventional Design Methodology
155 pp, November 1999, ISBN 90 376 0241 x
R11 Benchmarking of the Conventional Design Methodology
Summary report
33 pp, November 1999, ISBN 90 376 0251 7
R12-13 Probabilistic Calculations
130 pp, May 2000, ISBN 90 376 0401 3
R14a Durability Design of Concrete Pavements
Compliance Tests, Statistical Quantification and Benchmarking
134 pp, May 2000, ISBN 90 376 0381 5
R14b Durability Design of Concrete Pavements
Design Guide
122 pp, May 2000, ISBN 90 376 0371 8
R15 General Guidelines for Durability Design and Redesign
109 pp, February 2000, ISBN 90 376 0384 x
 |