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This paper investigates the shear behavior of unidirectional hybrid slabs made of a normal-strength concrete (NSC) substrate and an ultrahigh-performance concrete (UHPC) overlay on the tensile side. The impacts of two important aspects on the shear behavior were studied. First, various strengthening configurations (thickness, with or without NSC substitution, with existing and/or new rebars) were investigated, specifically two configurations scarcely studied in the scientific literature. Second, the state of damage of the NSC slab prior to the overlay application was examined for the first time. The hybrid slabs tested behaved monolithically until the establishment of a composite mechanical action occurring at up to 1.66 times the reference shear resistance. The composite mechanical action offered structural hardening with significant increase of shear resistance up to 2.50 times the reference shear resistance. Strain distribution and reorganization was monitored on the slabs using digital image correlation technology, and showed creation of a strut and tie system in four successive steps. Both the UHPC thickness and the total area of longitudinal rebar had a significant impact on the ultimate shear resistance. The effect of the load history on the ultimate shear resistance was limited, and partly masked by the combined effect of the type of NSC-UHPC interface and the overlay configuration influencing the crack pattern. [ABSTRACT FROM AUTHOR]

New designs of precast bridge parapets made with fibre reinforced concretes (FRC) were developed using nonlinear finite element calculations. A monolithic FRC parapet and a hybrid FRC parapet were designed. The latter parapet consisted of a shell of ultra-high performance FRC paired with a normal strength concrete core. Furthermore, two new anchorage systems were optimized for parapet installation on a new deck or for parapet replacement on an existing structure. Quasi-static tests showed that the load-carry capacity of the parapet designs exceed the PL-2 or TL-4 parapet specifications of CSA and AASHTO. The finite elements model developed in the project has satisfactorily reproduced the stiffness, ultimate strength, and failure mode of parapets. Additional numerical analyses were conducted for the hybrid parapet to provide design recommendations related to construction aspects and further optimizations. Key words: bridge, monolithic and hybrid parapets, high and ultra-high performance fibre reinforced concretes, anchorage system, nonlinear finite elements, parametric study, ultimate strength, failure mode, construction time. Resume: De nouvelles concepts de parapets prefabriques en beton renforces de fibres pour les ponts ont ete developpees au moyen de calculs par elements finis non lineaires. Un parapet monolithique en beton fibre et un parapet hybride en beton fibre a ultra-haute performance ont ete concus. Ce dernier consistait en une enveloppe beton fibre a ultra-haute performance jumelee a un noyau de beton de resistance normale. De plus, deux nouveaux systemes d'ancrage ont ete optimises pour l'installation des parapets sur un nouveau tablier de pont ou le remplacement de parapets sur une structure existante. Des essais quasi-statiques ont montre que la capacite portante des nouveaux concepts de parapets depassaient les specifications pour les parapets PL-2 ou TL-4 des normes CSA et AASHTO. Le modele par elements finis developpe dans le projet a reproduit de maniere satisfaisante la rigidite, la resistance a la rupture et le mode de defaillance des parapets. Des analyses numeriques supplementaires ont ete realisees pour le parapet hybride afin de fournir des recommandations reliees a la construction ainsi aux futures optimisations de ce type de parapet. Mots-cles: pont, parapets monolithiques et hybrides, beton renforces de fibres a haute et ultra-haute performance, systeme d' ancrage, elements finis non lineaires, etude parametrique, resistance a la rupture, mode de defaillance, temps de construction. [Traduit par la Redaction], Introduction The Canadian Highway Bridge Design Code (CSA 2006a) presently limits its design recommendations to continuous cast-on-site parapets anchored to bridge decks with conventional reinforcement (Fig. 1a). This method of [...]

Jean Lachaine,1,2 Jean-Nicolas Charron,2 Jean C Gregoire,3 Robert A Hegele,4 Lawrence A Leiter5 1University of Montreal, Montreal, QC, Canada; 2PeriPharm Inc., Montreal, QC, Canada; 3Institut de cardiologie de Montréal, Montreal, QC, Canada; 4Robarts Research Institute, London, ON, Canada; 5Li Ka Shing Knowledge Institute, St. Michael’s Hospital, University of Toronto, Toronto, ON, CanadaCorrespondence: Jean Lachaine, Faculty of Pharmacy University of Montreal, 2900 Edouard-Montpetit Blvd, Montreal, Quebec, H3T 1J4, Canada, Email jean.lachaine@umontreal.caBackground: Despite the use of statins, many patients with cardiovascular disease (CVD) have persistent residual risk. In a large Phase III trial (REDUCE-IT), icosapent ethyl (IPE) was shown to reduce the first occurrence of the primary composite endpoint of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or hospitalization for unstable angina.Methods: We conducted a cost-utility analysis comparing IPE to placebo in statin-treated patients with elevated triglycerides, from a publicly funded, Canadian healthcare payer perspective, using a time-dependent Markov transition model over a 20-year time horizon. We obtained efficacy and safety data from REDUCE-IT, and costs and utilities from provincial formularies and databases, manufacturer sources, and Canadian literature sources.Results: In the probabilistic base-case analysis, IPE was associated with an incremental cost of $12,523 and an estimated 0.29 more quality-adjusted life years (QALYs), corresponding to an incremental cost-effectiveness ratio (ICER) of $42,797/QALY gained. At a willingness-to-pay of $50,000 and $100,000/QALY gained, there is a probability of 70.4% and 98.8%, respectively, that IPE is a cost-effective strategy over placebo. The deterministic model yielded similar results. In the deterministic sensitivity analyses, the ICER varied between $31,823-$70,427/QALY gained. Scenario analyses revealed that extending the timeframe of the model to a lifetime horizon resulted in an ICER of $32,925/QALY gained.Conclusion: IPE represents an important new treatment for the reduction of ischemic CV events in statin-treated patients with elevated triglycerides. Based on the clinical trial evidence, we found that IPE could be a cost-effective strategy for treating these patients in Canada.Keywords: cardiovascular diseases, icosapent ethyl, IPE, cost-effectiveness, cost per QALY

Concrete T-beams are commonly used in building slab systems and bridge decks. They may require strengthening in shear when they are deteriorated or when loading requirements increased. This research project studied the shear behaviour of concrete T-beams using cast-in-place Ultra High-Performance Concrete (UHPC) layers as a lateral strengthening method avoiding beam depth modification. Three UHPC strengthened beams together with one reference reinforced concrete beam were tested in monotonic three-point bending. Parameters investigated include the thickness of UHPC layers and the presence of steel anchors at the UHPC-concrete interface. A digital image correlation (DIC) technique was used to investigate the strain distribution of T-beams during the testing. Strain distribution, failure modes and strengthening effects provided by the UHPC lateral strengthening were analyzed. Results show that UHPC strengthening can substantially improve the stiffness and shear capacity of concrete T-beams, 25 and 50 mm lateral layers increased by 102% and 113% the T-beam shear capacity, respectively. Typical bending-shear behaviour were observed on each strengthened beam with UHPC layers. A final shear failure was observed in the T-beam with 25 mm UHPC layers and 50 mm UHPC layers without anchors, while a combination of shear and bending failure was noted in the T-beam with 50 mm UHPC layers and steel anchors. The steel anchors at the UHPC-concrete interface can further increase the ultimate shear capacity and beam stiffness, but at a limited extent. Therefore, experimental results confirmed that cast-in-place UHPC lateral layers are an effective way to strengthen existing concrete T-beams with inadequate shear capacity