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Épernon, France

Juster-Lermitte S.,CEA Saclay Nuclear Research Center | Fournely E.,Clermont University | Lamadon T.,Bureau Veritas | Juraszek N.,CERIB
Bulletin de la Societe Geologique de France

Following the L'Aquila earthquake in 2009, AFPS (French Association of Earthquake Engineering) sent a mission to investigate the effects of this earthquake (seismological, structural and societal aspects were investigated). It has been observed that most of the damaged buildings were generally irregular in plan and/or in elevation and that their design details were not suitable to take into account the seismic risk. The damaged structures were generally located in the vicinity of L'Aquila, in a square area of 400 km2. This article presents the main observations of this mission regarding the structural behaviour of typical buildings in the L'Aquila surrounding, and investigates the advantage of a capacity design analysis. A special consideration is given to soil configurations in this area and will be related to each structural approach. Source

Morin C.,CERIB | Sedran T.,IFSTTAR | De Larrard F.,Lafarge | Dumontet H.,CNRS Jean Le Rond dAlembert Institute | And 3 more authors.
European Journal of Environmental and Civil Engineering

Pick excavatability of controlled low-strength materials was experimentally studied to circumvent the fact that current classification systems or empirical excavatability criteria lack relevance (they do not refer to digging facilities and depend on the mix design and the granular skeleton of the material). Manual excavation is separated into two steps: the impact of the pick and decompaction. This was analysed by a mechanical approach. Energy is mainly consumed during the first step. A laboratory punching test was therefore proposed to evaluate excavatability (a confined cylindrical specimen was loaded by a cylindrical punch). Results were compared between the mechanised and the manual pick excavation tests on field trenches backfilled with air-entrained mortars or very lean concretes. These comparisons confirmed that a limited compressive strength was an indicator of excavatability. A model was proposed to evaluate the excavated volume by punching penetration for a given level of energy and a maximum size of aggregates in the material. © 2013 Taylor & Francis. Source

Ait-Mokhtar A.,University of La Rochelle | Belarbi R.,University of La Rochelle | Benboudjema F.,Ecole Normale Superieure de Cachan | Burlion N.,Lille Laboratory of Mechanics | And 19 more authors.
Cement and Concrete Research

One of the main objectives of the APPLET project was to quantify the variability of concrete properties to allow for a probabilistic performance-based approach regarding the service lifetime prediction of concrete structures. The characterization of concrete variability was the subject of an experimental program which included a significant number of tests allowing the characterization of durability indicators or performance tests. Two construction sites were selected from which concrete specimens were periodically taken and tested by the different project partners. The obtained results (mechanical behavior, chloride migration, accelerated carbonation, gas permeability, desorption isotherms, porosity) are discussed and a statistical analysis was performed to characterize these results through appropriate probability density functions. © 2012 Elsevier Ltd. Source

Turcry Ph.,University of La Rochelle | Younsi A.,University of La Rochelle | Jacquemot F.,CERIB | Ait-Mokhtar A.,University of La Rochelle | Rougeau P.,CERIB
European Journal of Environmental and Civil Engineering

Probabilistic approaches to design reinforced concrete structures require the knowledge of distribution laws governing the statistical variability of concrete properties used as models inputs. The present work focuses on the variability of carbonation resistance throughout the construction period and inside an existing structure. Accelerated carbonation tests were carried out in a laboratory on more than 120 samples taken from two real building sites. Samples drilled from a bridge crosshead were also investigated. In the case of production-variability, the statistical distribution of the carbonation depths was found to be correctly modelled by a normal statistical distribution, as usually done for compressive strengths. However, these two properties appeared to be little correlated. Inside the structure, the carbonation resistance was shown to be higher with the distance to the surface of the drilled samples. In addition to experimental results, the efficiency of the accelerated carbonation test protocol, especially the preconditioning prior to carbonation, is discussed. © 2012 Taylor & Francis. Source

The objective of the present study was to reproduce the real state of stress in a tunnel segment in order to evaluate the spalling sensivity. Numerical tools have been used to predict the restrained axial forces which may appear due to the thermal expansion. A new experimental set up has been designed to withstand these forces. Thus the choice of a protected self-resistant slab to reproduce the surroundings has been done to test the loaded precast tunnel segment which withstood a two hour modified hydrocarbon fire with only limited amount of spalling. © Owned by the authors, published by EDP Sciences, 2013. Source

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