Abstract. We present version 1.0 of the ISOGAL-DENIS Point Source Catalogue (PSC), containing more than 100 000 point sources detected at 7 and/or 15 µm in the ISOGAL survey of the inner Galaxy with the ISOCAM instrument on board the Infrared Space Observatory (ISO). These sources are cross-identified, wherever possible, with near-infrared (0.8-2.2 µm) data from the DENIS survey. The overall surface covered by the ISOGAL survey is about 16 square degrees, mostly (95%) distributed near the Galactic plane (|b| < ∼ 1• ), where the source extraction can become confusion limited and perturbed by the high background emission. Therefore, special care has been taken aimed at limiting the photometric error to ∼0.2 mag down to a sensitivity limit of typically 10 mJy. The present paper gives a complete description of the entries and the information which can be found in this catalogue, as well as a detailed discussion of the data processing and the quality checks which have been completed. The catalogue is available at the Centre de Données Astronomiques de Strasbourg (via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/403/955) and also via the server at the Institut d'Astrophysique de Paris (http://www-isogal.iap.fr/). A more complete version of this paper, including a detailed description of the data processing, is available in electronic form through the ADS service and at http://www.edpsciences.org.

Abstract. The ISOGAL project is an infrared survey of specific regions sampling the Galactic Plane selected to provide information on Galactic structure, stellar populations, stellar mass-loss and the recent star formation history of the inner disk and Bulge of the Galaxy. ISOGAL combines 7 and 15 µm ISOCAM observations -with a resolution of 6 at worst -with DENIS IJK s data to determine the nature of the sources and the interstellar extinction. We have observed about 16 square degrees with a sensitivity approaching 10-20 mJy, detecting ∼10 5 sources, mostly AGB stars, red giants and young stars. The main features of the ISOGAL survey and the observations are summarized in this paper, together with a brief discussion of data processing and quality. The primary ISOGAL products are described briefly (a full desciption is given in Schuller et al. 2003): viz. the images and the ISOGAL-DENIS five-wavelength point source catalogue. The main scientific results already derived or in progress are summarized. These include astrometrically calibrated 7 and 15 µm images, determining structures of resolved sources; identification and properties of interstellar dark clouds; quantification of the infrared extinction law and source dereddening; analysis of red giant and (especially) AGB stellar populations in the central Bulge, determining luminosity, presence of circumstellar dust and mass-loss rate, and source classification, supplemented in some cases by ISO/CVF spectroscopy; detection of young stellar objects of diverse types, especially in the inner Bulge with information about the present and recent star formation rate; identification of foreground sources with mid-IR excess. These results are the subject of about 25 refereed papers published or in preparation.

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Long-term studies under various natural exposure conditions are still needed in order to understand and quantify ageing and durability of concrete structures, in particular in the case of mixtures which incorporate supplementary cementitious materials (e.g. fly ash). With this purpose, a large-scale and long-term experimental program was initiated a lot of years ago by the LPC network within the framework of the French national project "BHP 2000." From then, further researches have been carried out in order to complement the program. The present paper focuses on chloride penetration in concrete samples in lab conditions and in reinforced concrete (RC) structural elements exposed for 10 years to two different natural environments (tidal zone in marine environment, as well as road and cold environment). Numerous mixtures (28 day cylinder compressive strengths ranging from 20 to 130 MPa) were studied in these various conditions, e.g. high-performance materials with or without silica fume (SF), as well as normal-strength fly-ash (FA) concretes. Carbonation and chloride penetration depths, along with total chloride concentration and degree of saturation profiles, have been measured on the RC structural elements and analyzed as a function of the exposure conditions and of the mix-parameters. In addition, the chloride data have been compared to lab results. Apparent chloride diffusion coefficients, as well as chloride binding isotherms and capacities, have also been assessed on these structural elements and compared to lab results. Good consistence between results in field and in lab conditions has been highlighted, except when carbonation has affected the field results. In addition, the good performance of SF-HPCs and mature FA concretes has been pointed out in the tested outdoor conditions, as well as that of the mature ground granulated blast furnace slag concretes tested in lab.

Underground concrete structures may be subjected to external sulfate attack and their long-term performance is of concern. A coupled transport/chemical numerical model has been compared to experimental data obtained on a cement paste exposed to external sulfate attack thanks to recent developments in experimental analysis such as scanning electron microscopy and image analysis that provided total ion concentration profiles for a given species in cement paste specimens. As other studies the model succeeded in calculating the position of the ettringite precipitation front and the position of the first decrease due to the portlandite dissolution whereas the leaching of portlandite and ettringite was not accurately assessed in the first millimeters because of the necessity to take into account change of the transport properties in the degraded zone. Then a numerical parametric study was carried on. The influence of permanent solution renewal, pH control, and dissolved CO 2 concentration were analyzed. The accelerating effect of permanently renewing the solution was confirmed. The influence of the pH control was found dependent of the renewing of solution. The presence of CO 2 did not play a significant role.

In this paper, a physically and chemically based model, which describes coupled ion-moisture transport, is used to simulate chloride ingress in concrete elements subjected to wetting-drying cycles in marine environment. Various assumptions are tested, in order to quantify the influence of taking into account thermochemistry such as Friedel's and Kuzel's salts precipitation on the ingress kinetics or to underline the differences between complex model and very simple one (assuming saturated conditions in the latter case). Numerical simulations are compared to experimental chloride concentration profiles. Experimental data were obtained on an OPC concrete specimens exposed to 6h/6h seawater wetting-drying cycles in lab (where RH and T are controlled). The results show that when the initial amounts of hydration products are known, the assessment of the chloride binding parameters is not needed. In addition, including thermochemistry in the model improves the predictions, in particular with regard to pH value that can be used as rebar depassivation evaluation criterion. Moreover, the boundary layer thickness that reflects the evaporation kinetics is not an important parameter for the studied concretes. Updating at each time step the transport properties in order to account for dissolution / precipitation of mineral species does not change very much the chloride profiles as well. Furthermore, simulations carried out in saturated conditions do not provide similar results to those obtained when accounting for wetting-drying cycles for the studied concrete. Nevertheless, it may be possible to use a simple model, and thus avoid the problematic assessment of the "intrinsic" permeability, to predict RC service life in the case of lowpermeability concretes.

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