18 research outputs found

    Experimental investigation on the bond behavior of a compatible TRM-based solution for rammed earth heritage

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    Despite the current awareness of the high seismic risk of earthen structures, little has been done so far to develop proper strengthening solutions for the rammed earth heritage. Based on the effectiveness of TRM for masonry buildings, the strengthening of rammed earth walls with externally bonded fibers using earth-based mortar is being proposed as a compatible solution. In this context, the investigation of bond behavior was conducted by means of direct tensile tests, pull-out tests and single lap-shear tests. The specimens were prepared using earth-based mortars and two different types of meshes (glass and nylon) while considering different-bonded lengths. The direct tensile tests on TRM coupons showed the high capacity of the nylon mesh in transferring stresses after cracking of the mortar. The pull-out tests highlighted that in the case of glass fiber mesh, the bond was granted by friction, while the mechanical anchorage promoted by the transversal yarns granted the bond of the nylon mesh. Finally, the single lap-shear tests showed that the adopted earth-based mortar seems to limit the performance of the strengthening.This work was supported by the Fundacao para a Ciencia e a Tecnologia [PTDC/ECM-EST/2777/2014, SFRH/BD/131006/2017, SFRH/BPD/97082/2013]

    Influence of chloride contamination on carbonation of cement-based materials

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    An experimental investigation was conducted to understand the effect of the presence of chloride on the carbonation front. Microstructural analysis was conducted to verify the carbonation development in material previously contaminated by chlorides. Accelerated tests were combined to understand how the presence of chlorides influences carbonation front and how chloride test method influences in these results. The results indicate that the presence of chloride decreases the carbonation front in cementbased materials. This behaviour is related to the pore refinement and humidity retention caused by chloride. The impact on carbonation reduction occurs at different levels, according to the testing method used

    The SHARE European Earthquake Catalogue (SHEEC) 1000–1899

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    In the frame of the European Commission project “Seismic Hazard Harmonization in Europe” (SHARE), aiming at harmonizing seismic hazard at a European scale, the compilation of a homogeneous, European parametric earthquake catalogue was planned. The goal was to be achieved by considering the most updated historical dataset and assessing homogenous magnitudes, with support from several institutions. This paper describes the SHARE European Earthquake Catalogue (SHEEC), which covers the time window 1000–1899. It strongly relies on the experience of the European Commission project “Network of Research Infrastructures for European Seismology” (NERIES), a module of which was dedicated to create the European “Archive of Historical Earthquake Data” (AHEAD) and to establish methodologies to homogenously derive earthquake parameters from macroseismic data. AHEAD has supplied the final earthquake list, obtained after sorting duplications out and eliminating many fake events; in addition, it supplied the most updated historical dataset. Macroseismic data points (MDPs) provided by AHEAD have been processed with updated, repeatable procedures, regionally calibrated against a set of recent, instrumental earthquakes, to obtain earthquake parameters. From the same data, a set of epicentral intensity-to-magnitude relations has been derived,with the aimof providing another set of homogeneous Mw estimates. Then, a strategy focussed on maximizing the homogeneity of the final epicentral location and Mw, has been adopted. Special care has been devoted also to supply location and Mw uncertainty. The paper focuses on the procedure adopted for the compilation of SHEEC and briefly comments on the achieved results
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