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Interaction of ultrasonic waves with partially-closed surface-breaking cracks in concrete structures has been studied. Measurements have been conducted on a reinforced concrete beam containing various mechanical-load-induced cracks and compared with the baseline measurements at those locations. Influence of crack width, incident angle of waves with cracks, and distance from the cracks on travel time and amplitude of the waves have been investigated when the beam was unloaded. It has been observed that a measurable part of the waves propagate through the cracks due to the acoustic coupling between the crack faces, although attenuation can be relatively high. The travel time has shown a nearly independent behavior from remaining crack opening in the measured range of 0.05 mm to 3 mm. Measurements in directions orthogonal and parallel to the crack suggest that there is substantial anisotropy in the cracking zone. Furthermore, an effective width of the micro-cracking area around the cracks has been estimated from the measurements.

tNovel nanomaterials, such as nanosilica or nano-titanium oxide, have been developed in the last decadefor the conservation of the built heritage. Among nanomaterials, nanolimes have acquired a considerablerelevance due to their potentialities as consolidant product. The so-called nanolimes, colloidal disper-sions of calcium hydroxide nanoparticles in alcohols, have been successfully applied as pre-consolidantson frescos and paper, and their use has later been extended to plasters, renders and stone. Nanolimeshave better potentialities compared to conventional inorganic consolidants based on limewater (e.g.faster carbonation rate and higher calcium hydroxide concentration). Moreover, nanolimes are consid-ered more compatible with CaCO3-based substrates than alkoxysilanes (e.g. TEOS), the most widely usedconsolidant products. Nanolimes can guarantee the recovery of the superficial cohesion of degradedmaterials. However, when a mass consolidation is required, like in the case of decayed stone, nanolimesshow some limitations. One of the problems is caused by nanolime accumulation at or just beneath thesurface of the treated material. In order to solve this problem, the transport mechanism of nanolimewithin porous materials, as stone or renders, should first be better understood. Commercial nanolimeswere applied on Maastricht limestone, a high-porosity yellowish limestone, used in the Netherlands andBelgium as traditional building material. The absorption and drying behaviour of nanolime in this lime-stone was measured and nanolime deposition in the stone was studied by optical and scanning electronmicroscopy. The results show that nanolime transport is strictly related to the properties of the solvent.The alcoholic solvent guarantees a stable dispersion that penetrates in depth in the material, but is par-tially back-transported to surface. The high volatility of the solvent and the high stability of the dispersionfavour the partial back-migration of lime nanoparticles to the surface during drying

This paper considers local buckling of perforated square aluminium plates. Plates of various slenderness with simply supported edges and subjected to uniaxial compression are studied using the finite element method. Different perforation patterns are investigated, from a single circular hole to 25 circular holes distributed over the plate. A number of aluminium alloys are considered and compared to steel grade A36. Results show that the resistance of the plates containing a single central cut-out is higher than that of plates with more holes and of equal total cut-out size. A further refinement beyond 5 holes does not influence the resistance.

Carbonation of concrete at ambient CO2 concentration is a slow process. This makes the testing of the resistance of concrete against carbonation often too slow to be applicable for service life assessments of new structures. Raising the CO2-concentration will accelerate the test but the validity of an increase CO2-level is debated. If not valid, the service life can be seriously underestimated. In this paper, the effects of accelerating on the carbonation process are discussed. It is shown that a change in CO2 concentration will not change the carbonation process. Since carbonation occurs instantly, a zero CO2 concentration at the carbonation front is maintained. Moreover, it has been concluded that all hydrated and unhydrated cement ultimately carbonates. This implies that the amount of material that can carbonate can be determined on the basis of the amount of calcium in the unreacted cement. © 2013 Elsevier Ltd. All rights reserved.

The Proterozoic Bamble Sector, South Norway, is one of the world's classic amphibolite- to granulite-facies transition zones. It is characterized by a well-developed isograd sequence, with isolated ‘granulite-facies islands’ in the amphibolite-facies portion of the transition zone. The area is notable for the discovery of CO2-dominated fluid inclusions in the granulite-facies rocks by Jacques Touret in the late 1960's, which triggered discussion of the role of carbonic fluids during granulite genesis. The aim of this review is to provide an overview of the current state of knowledge of the Bamble Sector, with an emphasis on the Arendal-Froland-Nelaug-Tvedestrand area and off shore islands (most prominantly Tromøy and Hisøy) where the transition zone is best developed. After a brief overview of the history of geological research and mining in the area, aspects of sedimentary, metamorphic and magmatic petrology of the Bamble Sector are discussed, including the role of fluids. Issues relevant to current geotectonic models for SW Scandinavia, directly related to the Bamble Sector, are discussed at the end of the review.

The paper describes the methodology followed for the development of new cool products in order to widen the range of existing solutions both including coloured (even dark) materials and extending the application also to building vertical components. Cool coloured ceramic tiles and acrylic paints for façades and roof membranes have been developed and tested at lab scale. Spectral reflectance measurements have been performed demonstrating a significant improvement of reflectance in the Near InfraRed (NIR) range (up to. +0.40) while keeping dark colour and high absorbance in the visible. The development of new products has been also oriented to the improvement of durability properties, being this aspect of relevance for high reflecting materials that have to keep their cooling properties over the time. While ceramic tiles naturally offer superior resistance to outdoor ageing, a significant increase of biological growth resistance has been achieved also for roof membranes by including ZnO nanoparticles. The approach followed by the authors aimed at delivering products, that besides having higher NIR reflectance, were capable of satisfying industrial and market requirements being compatible with standard manufacturing processes and offering additional functionalities. A complementary paper will be dedicated to the extensive experimental and numerical evaluation of new materials' thermal performances. © 2014 Elsevier Ltd.

Stand-off photovoltaic systems are a popular measure for retrofitting of existing pitched roofs. Panels are generally mounted parallel to the existing roof coverings, usually roofing tiles. Full scale and wind tunnel experiments have been performed to determine the net uplift loads on these systems, which can be applied to calculate the loadbearing system. In the wind tunnel, the effect of distance between panel and roof has been investigated. Results show that loads can be expected that are substantially lower than the external loads on the roof surface, as given in wind loading standards. The effect of distance between PV system and roof surface is relatively small. The loads on the underlying roof are not significantly higher or lower compared to the case without system.

Weld improvement techniques are aimed at reducing the notch effects of welds and generally focus on two aspects: a change of geometry of the weld toe and a change of the weld residual stresses. In this paper, fatigue tests are discussed, performed on butt welded specimens in steel grades ranging from S460 to S1100 in the TIG-dressed condition. The test results are compared with modelled fatigue strength according to the notch stress theory and similar specimens in the as-welded condition. The changed notch geometry of the joints is based on the results of a parallel program of weld toe geometry measurements.The individual data points and their failure mode give good qualitative insight in the effect of TIG-dressing on butt welded joints in high strength steel. Overall, a positive effect of TIG-dressing on the weld toe is visible.On the basis of a large dataset of measured weld toe geometries a model has been developed based on the notch stress theory. The theoretical results of the model are compared with the results of the physical tests, showing significant differences between the model and the fatigue tests.

The fatigue behaviour of aluminium shows not only many similarities, but also some differences with the fatigue behaviour of steel. There exist separate Eurocodes for the fatigue design of steel and of aluminium structures, EN1993-1-9 and EN1999-1-3, respectively. The latter standard was developed after the draft version of the first one was available. However, a number of aspects are considered in a different way in the two standards. Are these differences justified and desired? What can we learn from the two standards for future improvement of the documents? This paper presents and discusses the agreements and differences between the two Eurocodes. The paper evaluates the advantages and disadvantages of the approaches adopted in one or another of the two standards. It may serve as a starting point for future harmonization of the two standards. © 2013 The Authors. Published by Elsevier Ltd.