Alkali Silica Reaction in concrete: the Argentinian experience

Argentina is an extended country where a large variety of aggregates is available even in the same region. More than 100 examples of structures, placed in regions with different climates, damaged by ASR have been reported since 1950. Many tests on mortar or concrete involving different temperatures, alkali contents, and sample volumes have been studied in order to find the most suitable conditions for the evaluation of reactive aggregates. This paper summarizes the present knowledge and design criteria adopted in Argentina in order to avoid or mitigate ASR in concrete.Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica (LEMIT

Alkali Silica Reaction in concrete: the Argentinian experience

Argentina is an extended country where a large variety of aggregates is available even in the same region. More than 100 examples of structures, placed in regions with different climates, damaged by ASR have been reported since 1950. Many tests on mortar or concrete involving different temperatures, alkali contents, and sample volumes have been studied in order to find the most suitable conditions for the evaluation of reactive aggregates. This paper summarizes the present knowledge and design criteria adopted in Argentina in order to avoid or mitigate ASR in concrete.Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica (LEMIT

Reacción álcali-sílice en hormigones con fibras

La reacción álcali-sílice (RAS) reviste interés en Argentina considerando la gran variedad de agregados potencialmente reactivos. Pocos estudios tratan sobre la contribución potencial de las fibras para mitigar el proceso de degradación y sobre si la RAS modifica la capacidad residual del hormigón. Este trabajo discute los efectos del uso de fibras en el desarrollo de la RAS, en base al estudio de bloques de hormigón expuestos al aire libre durante cuatro años. Comprende tres hormigones elaborados con agregado grueso reactivo y adición de álcalis, uno sin fibras, otro con 40 kg/m3 de fibras de acero y el tercero con 3 kg/m3 de macrofibras sintéticas, más un cuarto hormigón de referencia sin adición de fibras ni de álcalis. Se analizan las expansiones, la permeabilidad y el desarrollo de fisuras. Si bien las fibras no inhibieron la RAS atenuaron las expansiones y el cuadro de fisuración.Facultad de Ingenierí

Reacción álcali-sílice en hormigones con fibras

La reacción álcali-sílice (RAS) reviste interés en Argentina considerando la gran variedad de agregados potencialmente reactivos. Pocos estudios tratan sobre la contribución potencial de las fibras para mitigar el proceso de degradación y sobre si la RAS modifica la capacidad residual del hormigón. Este trabajo discute los efectos del uso de fibras en el desarrollo de la RAS, en base al estudio de bloques de hormigón expuestos al aire libre durante cuatro años. Comprende tres hormigones elaborados con agregado grueso reactivo y adición de álcalis, uno sin fibras, otro con 40 kg/m3 de fibras de acero y el tercero con 3 kg/m3 de macrofibras sintéticas, más un cuarto hormigón de referencia sin adición de fibras ni de álcalis. Se analizan las expansiones, la permeabilidad y el desarrollo de fisuras. Si bien las fibras no inhibieron la RAS atenuaron las expansiones y el cuadro de fisuración.Facultad de Ingenierí

Alkali Silica Reaction in concrete: the Argentinian experience

Argentina is an extended country where a large variety of aggregates is available even in the same region. More than 100 examples of structures, placed in regions with different climates, damaged by ASR have been reported since 1950. Many tests on mortar or concrete involving different temperatures, alkali contents, and sample volumes have been studied in order to find the most suitable conditions for the evaluation of reactive aggregates. This paper summarizes the present knowledge and design criteria adopted in Argentina in order to avoid or mitigate ASR in concrete.Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica (LEMIT

Impact of Preoperative Patient Characteristics and Flow Rate on Failure, Early Complications, and Voiding Dysfunction After a Transobturator Tape Procedure: A Multicentre Study

Purpose: To evaluate the impact of preoperative patient characteristics and flow rate on failure, early postoperative complications, and voiding in patients who underwent transvaginal tension-free vaginal tape-obturator (TVT-O) treatment for uncomplicated stress urinary incontinence (SUI).Methods: We retrospectively reviewed patients who underwent TVT-O for SUI at 3 Italian centres. The exclusion criteria were predominant voiding and storage symptoms suggestive of detrusor overactivity, the presence of grade > 1 urogenital prolapse, previous pelvic radiotherapy or other clinical contraindications for surgical procedures, neurogenic bladder dysfunction, and collagen diseases. Multivariate logistic regression models were constructed to identify predictors of early voiding dysfunction after TVT-O.Results: A total of 219 patients underwent TVT-O between January 2010 and December 2015. All patients received follow-up at 3, 6, and 12 months, and underwent a stress test, uroflowmetry, and bladder ultrasound to evaluate the postvoid residual volume. They also responded to the Urogenital Distress Inventory (UDI-6) questionnaire. The rates of persistent incontinence after TVT-O, postoperative complications, and satisfaction were 16.4% (36 of 219), 24.2% (53 of 219), and 86.3% (189 of 219), respectively. Nineteen patients (9.5%) experienced early voiding dysfunction. Based on an analysis of baseline characteristics, we determined that a cutoff value of 9.0 on the UDI-6 predicted postoperative SUI with 62% specificity, 72% sensitivity, and 66% accuracy. In the multivariate logistic regression analysis, a preoperative UDI-6 >= 9.0 was an independent predictor of postoperative SUI. The predictors of complications were menopause (P = 0.04) and the preoperative UDI-6 score (P = 0.01).Conclusions: Menopause and UDI-6 scores could be prognostic factors for persistent SUI after TVT-O. Well-designed prospective studies with a suitable number of patients are needed to corroborate our findings

AdaptMap: exploring goat diversity and adaptation

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