Newsletter PERFDUB – November 2016
Latest news of the French National Project PERFDUB
The National Project PERFDUB (2015 – 2019) gathers 50 partners, stakeholders in the construction industry (Owners, Engineering, Contractors, Researchers, and Manufacturers/suppliers). Its main objective is to define at a national scale a methodology for justifying durability of concrete (and concrete structures) with a performance-based approach, including the “absolute” and “comparative” methods. It aims to aggregate the knowledge and feedback, to fill gaps, in a framework involving all stakeholders so that the performance-based approach becomes operational and common.
Workgroup n°5 “Dissemination” set up a follow-up committee with 14 international experts from 11 different countries, mostly Europe. The main objective of the committee is to promote, acknowledge the research works and results from the National Project PERFDUB at an international level, particularly within workgroups of the European Committee for Standardization.
The first meeting of this committee took place on October 3th, 2016 in Paris (France), involving 14 international experts as well as 13 speakers from the project to present a state of the art on the performance-based approach in France and the general program of the National Project PERFDUB, the test methods and concrete to be studied, the “absolute” approach and finally the contractual methodology. This meeting allowed to sensitize these experts to the French PERFDUB approach, successfully initiate discussions and collect outer points of view which will benefit to the project.
A series of 41 concretes mix-designs were defined by workgroup n°3, based on 5 different types of aggregates, 9 cements and 6 additions, including:
- 20 mix-designs compliant with the exposure classes defined in Standard NF EN 206/CN (XC, XD/XS, XF, XA) according to the prescriptive approach;
- 21 mix-designs non-compliant with the prescriptive approach.
All these mixes constitute the main design of experiments in the National project PERFDUB. Admixtures will be adapted depending on their compatibility with the chosen cements and targets in terms of rheological behaviour.
Concretes will be characterized by workgroup n°1 throughout the project.
Harmonisation of tests methods
The first exchanges allowed to harmonize and to develop the standard methods of some durability tests from recent results. These tests methods have been used in a round robin tests campaign involving 5 certified laboratories, completed by parametric studies. Some results are already available: accelerated carbonation, resistivity and chloride migration, porosity and capillary absorption, gas permeability tests.
An exhaustive and thorough analysis of the obtained results will allow to provide all the project partners with an upgraded version of test methods at the beginning of 2017, which will be used to characterize the 41 study concretes defined within the framework of the project.
A dedicated team is currently working on external chemical attacks (external sulfatic attack, biodegradation and leaching) using both accelerated degradation tests in the lab and degradation monitoring on site.
Investigation of old structures
Workgroup n°2 “Definition of performance thresholds” is currently leading partial or full investigations of about ten old structures, classified in 3 categories:
- up to 20-years old structures,
- structures from 20 to 50 years-old,
- structures over 50-years old.
In addition to these investigations, samples have been taken on BHP 2000 project test specimens (20-years old).
An in-depth analysis of the evolution of durability indicators on these old structures will be done at the beginning of 2017 in order to check the relevance of the thresholds values currently proposed for each indicator and exposure class. The main interest of this study is to be able to evaluate these thresholds with hindsight. Durability tests, performed in association with others investigation techniques, are vital tools to assess and predict the ageing of operational structures.
PERFDUB introduced to the members of the European Technical Committee for Standardization CEN/TC51
The plenary meeting of the CEN/TC 51, the European Technical Committee for standardization in charge of Cements and building Limes, took place in Luxemburg on 12&13 October 2016.
Sandrine Mansoutre (co-animator of the WG5 for PERFDUB Valorisation and head of delegation of France at TC51) has been invited by the CEN/TC51 President to introduce the main lines of the French Nation Project PERFDUB to the European representatives.
PERFDUB at the Technical Day COTITA Ouest
“Designing, building and managing sustainable concrete structures”
On November 9th, 2016, a Technical Day was organized in Saint-Brieux by COTITA Ouest on “Designing, building and managing sustainable concrete structures”, regarding the evolution of standard and regulations as well as the performance-based approach.
François Cussigh (Vinci Construction, Director of NP PERFDUB) presented the project during session “Feedbacks and on-going studies”.
- administered par l’IREX (Institut pour la Recherche appliquée et l’EXpérimentation en génie civil),
- supported by the DGITM (Direction Générale des Infrastructures, des Transports et de la Mer) du MEEM (Ministère de l’Ecologie, de l’Environnement et de la Mer),
- supported by the ANR (Agence Nationale de la Recherche) dans le cadre du projet ANR MODEVIE.