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A numerical method based on Computational Fluid Dynamics is applied for a preliminary study of the relationship between driving rain and building envelope pathology (facade surface disfigurement). The study is conducted for the case of the ceramic brick facade of a low-rise office building. It will be shown that the numerical method can be used to explain disfigurement patterns that are caused by direct driving rain impingement.

After about 20 years in service, large sections of the concrete apron at Bari Civil Airport (Italy) shows evident structural problems. Slabs are principally affected by structural cracks and by shallow and deep spallings at joints. Present and forecast traffic data were collected and compared with the bearing capacity of the pavement as well as with typologies and positions of distresses. In particular it has been assessed that construction joints fatigue life has nearly expired. According to the results of field investigations, the effectiveness of current repair methods was investigated and original repair methods were developed both for spalled and cracked slabs. They concern the partial reconstruction of slabs with a double layer of a new fibro-reinforced concrete. Some trial repairs were carried out. After one year they showed no structural problems. So repairs are now in progress on the main apron of Bari Civil Airport using these construction methods. For the covering abstract see ITRD E118503.

Traditionally, static layered elastic analysis analyzes a pavement structure without any discontinuity under peak static load. This paper presents the results of several comprehensive three Dimensional-Finite Element (3D-FE) studies for asphalt highway pavement structures subjected to the Falling Weight Deflectometer (FWD) non destructive dynamic deflection tests. The results provide useful insight into pavement structural responses for un cracked and cracked pavements. This is not possible from traditional static linear elastic analysis or 2D finite element analysis. The use of infinite element with smaller size pavement model needs caution as it significantly decreases peak deflection values. The explicit dynamic analysis results for the FWD dynamic load, considering both system damping and Rayleigh damping, indicate that at a damping ratio of 5%, the damping forces lead to 1 to 9% smaller peak deflections. Additionally, natural frequency analysis and modeling of cracks in pavements and resulting reductions in modulus values are also discussed.

Bed joint reinforcement consisting of unprotected carbon steel was widely used to bridge windows and other openings in post-war brick buildings in the Scandinavian countries. Today, cracking caused by reinforcement corrosion constitute an increasing technical and economic problem, since removal of the corroding reinforcement can be both labour intensive and costly. Retrofitting measures are usually only based on an ocular inspection of the crack frequency, which give sub-optimal retrofitting results due to a lack of knowledge concerning the actual corrosion damage in the wall. The extent of retrofitting measures varies between partial removal of reinforcement from cracked joints to the removal of all reinforcement. This practice is problematic, since the level of retrofitting is not related, in a rational way, to the expected future development of the corrosion related damage. The objective of the presented field survey is to increase knowledge about factors influencing corrosion of bed joint reinforcement and by this provide input to development of rational decision making tools concerning retrofitting. The field survey deals with ocular examination of cracking and decay related to corrosion of reinforcement embedded in joints above windows and other openings. The field survey is complemented by examination and measurement of the corrosion depth in reinforcement collected from the field. The results show a strong dependence of crack formation on the corrosion depth of the embedded reinforcement related to differences in hygro-thermal conditions in the facade, that in turn depend on e.g. orientation, height, sheltering and the number of reinforcement bars in the bed joints.

Sixth International Conference on Structural Engineering, Mechanics and Computation (SEMC 2016), Cape Town, South Africa, 5 to 7 September 2016

Single-leaf vaults are acknowledged as particularly vulnerable to seismic actions: remark- able damages and collapses were surveyed on these elements after recent earthquakes, regardless of the earthquake intensity and of the level of the structure global damage. After a brief discussion on the seismic vulnerability of single-leaf vaults, a new strengthening technique for the reduction of the seis- mic vulnerability of single-leaf vaults is presented in this paper. Extrados lightweight plywood center- ings applying passive confinement are conceived to delay the onset of the vault failure mechanism. The reinforcement is designed as a 3-hinged arch, hinged constrained at the springing and at the vault key section to allow accommodating the small relative displacements of the vault springing, which may fol- low the deformation of possible internal ties or roof box structure. The extrados centring is a lightweight and dry solution, which does not require special man labour. The technique is reversible and minimally impairing of the structure integrity, thus respectful of the major restauration principles. The effectiveness of the solution is verified through an experimental study on the behaviour of a strengthened single-leaf vault subjected to cyclic distributed unsymmetrical loads. The efficiency of the strengthening is assessed through comparison with the seismic response of a reference unreinforced single leaf vault, tested in a previous research study.

Early age endogenous deformations due to concrete hydration heat, shrinkage and creep can represent a real cracking risk for composite bridge beams. The phenomenon is very complex and difficult to be taken into ac-count by designers of composite bridges, as it takes place when material properties of concrete are quickly changing in time. Recommendations on this topic in design codes and literature are generally scarce and some-times ambiguous; for instance, EN 1994-2 and SETRA Guidance book Eurocodes 3 and 4 give contradicting indications. The aim of this work is to perform three sets of non-linear thermo-mechanical analyses on three different bridges: a simply supported one with two-beam girder (50m span) and two continuous ones, the first with two-beam girder (40+50+40m spans), and the second with orthotropic box shaped section (60+80+60m spans). The analyses will show the differences between the bridge typologies and will help to understand the relevance of the hyperstatic behaviour in continuous beams

During the construction of concrete structures such as bridges, many deficiencies may occur due to an incorrect application or changes in the original design plans and construction errors. Frequently, areas with very poorly vibrated concrete, insufficiently grouted tendon ducts and incorrectly positioned reinforcement bars appear. Thus, the detection of these construction deficiencies is essential to prevent further damage to the bridge. Subsequently, a concrete specimen was prepared aimed at simulating some of the problems that can occur during the construction. The specimen was then mapped using a GPR system to check the effectiveness of this tool to provide information about those deficiencies. The acquisition was carried out in reflection mode and the results were further processed using 3D reconstruction software in order to obtain a more realistic and comprehensible image. These measurements showed rather good results. The 3D image provided much more detailed information about the elements placed inside the specimen relatively to 2D radargrams, which are generally used for primary target identification.