Numerical Study of the Bond Strength Evolution of Corroded Reinforcement in Concrete in Pull‐Out Tests

The corrosion of rebars in reinforced concrete structures impacts their geometry (diameter and ribs) and mass, damages the concrete at the interface between the two materials, deteriorates the bond strength, and causes the cracking of the concrete cover. In the following study, a 2D numerical model of the pull‐out test is presented in order to study the impact of corrosion on the bond strength. Several parameters are investigated: the embedment depth, the rebar’s diameter, and the width of the concrete cover. The model reproduces the slip of the rebar and the failure through the splitting of concrete. It integrates an interface between the two materials and a concrete damage model that simulate the deterioration of concrete in compression and tension. The results obtained are validated with experimental data from the literature. Moreover, a parametric study is carried out to determine the impact of the embedment depth, the diameter of the rebar, and the concrete cover on the bond strength. The present study confirms that a greater embedment depth increases the pulling load. The study also confirms that the rebar’s diameter impacts highly the loss of bond between the rebar and the concrete cover. Lastly, the final main result of this paper is that the width of the concrete cover slows the loss of bond strength between the two materials

Cystadénome Papillaire de L’épididyme: Un Nouveau Cas

Le cystadénome papillaire de l’épididyme est une tumeur paratesticulaire bénigne rare. Se présentant comme une masse épididymaire uni ou bilatérale. Son association avec le syndrome de Von Hippel-Lindau est fréquente, en particulier dans les lésions bilatérales. Nous rapportons l’observation d’un patient âgé de 36 ans, qui présentait depuis un an des douleurs scrotales gauches, une grosse bourse chronique, sans fièvre ni signes fonctionnels urinaires. L’examen avait mis en évidence une masse testiculaire dure, irrégulière et indolore sans adénopathies inguinales ni masse abdominale. L’échographie scrotale avait montré une masse testiculaire gauche solide hypoéchogène bien limitée de 3 x 2,5 x 2,2 cm. Les marqueurs tumoraux étaient normaux (ßHCG : 2 UI/j, AlphaFoetoProteine : 2,94 UI/l). La masse testiculaire a été explorée à travers une incision inguinale gauche. A la palpation, c’était une tumeur testiculaire dure. Une orchidectomie gauche a été réalisée. L’examen anatomopathologique de la pièce d’exérèse avait conclu à un aspect morphologique et immunohistochimique d’un cystadénome papillaire séreux borderline paratesticulaire sans signe d’invasion. A travers notre observation et les données de la littérature, nous proposons de mieux définir le diagnostic clinique et anatomopathologique ainsi que le traitement de ces tumeurs testiculaires rares.Mots clés : épididyme, cystadénome papillaire

Laparoscopic nephrectomy for giant staghorn calculus with non-functioning kidneys: Is associated unsuspected urothelial carcinoma responsible for conversion? Report of 2 cases

BACKGROUND-: Neglected renal stones remain a major cause of morbidity in developing countries. They not only result in functional impairment of affected kidney, but also act as an important predisposing factor for development of urothelial neoplasms. It is not uncommon to miss an associated urothelial tumor in a patient of nephrolithiasis preoperatively. CASE PRESENTATION-: In last 3 years, we came across two patients with giant staghorn calculus and poorly functioning kidneys who underwent laparoscopic nephrectomy. In view of significant perirenal adhesions & loss of normal tissue planes both these patients were electively converted to open surgery. The pathological examination of specimen revealed an unsuspected urothelial carcinoma in both these patients. The summary of our cases and review of literature is presented. CONCLUSION-: It is important to keep a differential diagnosis of associated urothelial malignancy in mind in patient presenting with long standing renal calculi. The exact role of a computerized tomography and cytology in preoperative workup for detection of possible associated malignancy in such condition is yet to be defined. Similarly if laparoscopic dissection appears difficult during nephrectomy for a renal calculus with non-functional kidney, keeping a possibility of associated urothelial malignancy in mind it is advisable to dissect in a plane outside gerotas fascia as for radical nephrectomy

Metastase osseuse solitaire d'un adenocarcinome renal

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Apport de la paparoscopie dans le traitement des testicules impalpables: Experience du service d'urologie de Casablanca

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Schwannome Benin retroperitoneal A propos de duex cas

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La pyelonephrite xanthogranulomateuse a propos de deux cas

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Crack front waves: A 3D dynamic response to a local perturbation of tensile and shear cracks

Crack front waves are long-lived perturbations propagating along the crack front. They are triggered by heterogeneities on the crack plane, as for instance tough asperities, which disturb the crack front shape. Crack front waves are thought to leave a trace on fracture surfaces, and are important elements for post mortem analysis. This paper presents a numerical analysis of crack front waves for tensile and shear cracks in the subsonic regime. The elastodynamics calculations are conducted with a boundary integral method. They reveal that the propagation velocity of these waves is independent of the fracture mode. Moreover, using a Lorentz transformation, we demonstrate that their speed is constant within the crack front moving frame, with a value slightly lower than the Rayleigh wave speed. Finally, we shed a new light on how, in response to the interaction with an asperity of prescribed size and toughness contrast, these waves select a localized perturbation in the velocity profile of characteristic shape, width and amplitude. (C) 2019 Elsevier Ltd. All rights reserved