Flexural Performance and End Debonding Prediction of NSM Carbon FRP-Strengthened Reinforced Concrete Beams under Different Service Temperatures.

This paper aims to evaluate the influence of relatively high service temperatures (near or beyond the glass transition temperature (Tg) of epoxy adhesive) on the flexural performance and end debonding phenomenon in near-surface mounted (NSM) carbon fiber-reinforced polymer (CFRP)-strengthened, reinforced concrete (RC) beams. To this end, an experimental program consisting of 24 beams (divided into four groups) was performed, where different parameters was combined (i.e., service temperature, steel reinforcement ratio, CFRP ratio, and concrete compressive strength). In addition, the effect of the testing temperature on the end debonding phenomenon was investigated with an analytical procedure according to fib Bulletin 90, and the predictions were compared to experimental results. Taking specimens tested at 20 °C as a reference, no considerable change was observed in the ultimate load of the specimens tested below 60 °C (being in the range of epoxy Tg), and all specimens failed by FRP rupture. On the other hand, the increase in testing temperature up to 70 and 85 °C was followed by a decrease in the capacity of the strengthened beams and a change in failure mode, moving from FRP rupture to end debonding and concrete crushing. The analytical procedure successfully predicted the occurrence of premature end debonding failure and demonstrated that the effect of temperature on the mechanical properties of materials can be a key factor when predicting the premature end debonding in a NSM joint.

Assessment of fib Bulletin 90 Design Provisions for Intermediate Crack Debonding in Flexural Concrete Elements Strengthened with Externally Bonded FRP.

With the assessment of intermediate crack debonding (ICD) being a subject of main importance in the design of reinforced concrete (RC) beams strengthened in flexure with externally bonded fibre-reinforced polymer (FRP), several approaches to predict the debonding loads have been developed in recent decades considering different models and strategies. This study presents an analysis of formulations with different levels of approximation collected in the fib Bulletin 90 regarding this failure mode, comparing the theoretical predictions with experimental results. The carried-out experiments consisted of three RC beams strengthened with carbon FRP (CFRP) tested under a four-point bending configuration with different concrete strengths and internal steel reinforcement ratios. With failure after steel yielding, higher concrete strength, as well as a higher reinforcement ratio, lead to a higher bending capacity. In addition, the performance of the models is assessed through the experimental-to-predicted failure load ratios from an experimental database of 65 RC beams strengthened with CFRP gathered from the literature. The results of the comparative study show that the intermediate crack debonding failure mode is well predicted by all models with a mean experimental-to-predicted failure load ratio between 0.96 and 1.10 in beams tested under three- or four-point bending configurations.

Influence of Bond Characterization on Load-Mean Strain and Tension Stiffening Behavior of Concrete Elements Reinforced with Embedded FRP Reinforcement.

Based on the characterization of the bond between Fiber-Reinforced Polymer (FRP) bars and concrete, the structural behavior of cracked Glass-FRP (GFRP)-Reinforced Concrete (RC) tensile elements is studied in this paper. Simulations in which different bond-slip laws between both materials (FRP reinforcement and concrete) were used to analyze the effect of GFRP bar bond performance on the load transfer process and how it affects the load-mean strain curve, the distribution of reinforcement strain, the distribution of slip between reinforcement and concrete, and the tension stiffening effect. Additionally, a parametric study on the effect of materials (concrete grade, modulus of elasticity of the reinforcing bar, surface configuration, and reinforcement ratio) on the load-mean strain curve and the tension stiffening effect was also performed. Results from a previous experimental program, in combination with additional results obtained from Finite Element Analysis (FEA), were used to demonstrate the accuracy of the model to correctly predict the global (load-mean strain curve) and local (distribution of strains between cracks) structural behavior of the GFRP RC tensile elements.

Analysis of the Impact of Sustained Load and Temperature on the Performance of the Electromechanical Impedance Technique through Multilevel Machine Learning and FBG Sensors.

The electro-mechanical impedance (EMI) technique has been applied successfully to detect minor damage in engineering structures including reinforced concrete (RC). However, in the presence of temperature variations, it can cause false alarms in structural health monitoring (SHM) applications. This paper has developed an innovative approach that integrates the EMI methodology with multilevel hierarchical machine learning techniques and the use of fiber Bragg grating (FBG) temperature and strain sensors to evaluate the mechanical performance of RC beams strengthened with near surface mounted (NSM)-fiber reinforced polymer (FRP) under sustained load and varied temperatures. This problem is a real challenge since the bond behavior at the concrete-FRP interface plays a key role in the performance of this type of structure, and additionally, its failure occurs in a brittle and sudden way. The method was validated in a specimen tested over a period of 1.5 years under different conditions of sustained load and temperature. The analysis of the experimental results in an especially complex problem with the proposed approach demonstrated its effectiveness as an SHM method in a combined EMI-FBG framework.

Performance of Linear Mixed Models to Assess the Effect of Sustained Loading and Variable Temperature on Concrete Beams Strengthened with NSM-FRP.

Although some extended studies about the short-term behavior of NSM FRP strengthened beams have been carried out, there is a lack of knowledge about the behavior of this kind of strengthening under sustained loads and high service temperatures. Electromechanical impedance method formulated from measurements obtained from PZT patches gives the ability for monitoring the performance and changes experienced by these strengthened beams at a local level, which is a key aspect considering its possible premature debonding failure modes. This paper presents an experimental testing program aimed at investigating the long-term performance of a concrete beam strengthened with a NSM CFRP laminate. Long term performance under different levels of sustained loading and temperature conditions is correlated with EMI signatures processed using Linear Mixed-effects models. These models are very powerful to process datasets that have a multilevel or hierarchical structure as those yielded by our tests. Results have demonstrated the potential of these techniques as health monitoring methodology under different conditions in an especially complex problem such as NSM-FRP strengthened concrete structures.

Experimental Study of the Effect of High Service Temperature on the Flexural Performance of Near-Surface Mounted (NSM) Carbon Fiber-Reinforced Polymer (CFRP)-Strengthened Concrete Beams.

This paper presents a study of the effect of high service temperature (near or beyond glass transition temperature (Tg) of structural epoxy adhesive) on the behavior of near-surface mounted (NSM) carbon fiber-reinforced polymer (CFRP)-strengthened reinforced concrete (RC) beams. The study includes experimental work as well as analytical and numerical analysis. To this end, fourteen beams have been tested up to failure in two different series. In series 1, specimens with three different CFRP areas have been tested at two different temperatures (i.e., 20 and 40 °C). In series 2, and with the aim of evaluating the effect of higher temperatures, only one CFRP area was tested under four different temperatures (i.e., 20, 60, 70, and 85 °C). Experimental results are evaluated in terms of load-deflections, failure modes, and bond performance. Furthermore, the experimental load-deflection curves are satisfactorily compared to both analytical predictions and finite element (FE) numerical simulations. In both cases, shrinkage and temperature effects on the short-term response of flexural elements have been accounted for. No significant reduction in stiffness and ultimate load was observed for specimens being tested up to 60 °C (in the range of epoxy Tg), showing FRP rupture failure in all of them. For specimens under 70 and 85 °C, the failure mode changed from FRP rupture to FRP end debonding and concrete crushing, respectively.

Characterization and Simulation of the Bond Response of NSM FRP Reinforcement in Concrete.

The near-surface mounted (NSM) technique with fiber reinforced polymer (FRP) reinforcement as strengthening system for concrete structures has been broadly studied during the last years. The efficiency of the NSM FRP-to-concrete joint highly depends on the bond between both materials, which is characterized by a local bond-slip law. This paper studies the effect of the shape of the local bond-slip law and its parameters on the global response of the NSM FRP joint in terms of load capacity, effective bond length, slip, shear stress, and strain distribution along the bonded length, which are essential parameters on the strengthening design. A numerical procedure based on the finite difference method to solve the governing equations of the FRP-to-concrete joint is developed. Pull-out single shear specimens are tested in order to experimentally validate the numerical results. Finally, a parametric study is performed. The effect of the bond-shear strength slip at the bond strength, maximum slip, and friction branch on the parameters previously described is presented and discussed.

Why do many basic packages of health services stay on the shelf? A look at potential reasons in the WHO South-East Asia Region.

Basic packages of health services (BPHSs) are often envisaged primarily as political statements of intent to provide access to care, in an era of commitment to universal health coverage. They are often produced with little attention paid to health systems' capacity to deliver these benefit packages or other implementation challenges. Many countries of the World Health Organization (WHO) South-East Asia Region have invested in developing BPHSs. This perspective paper reflects on the issues that do not receive enough attention when packages are developed, which can often jeopardize their implementation. Countries of the region refer to burden-of-disease assessments and consider the cost-effectiveness of the listed interventions during their BPHS design processes. Some also conduct a costing study to generate "price tags" that are used for resource mobilization. However, important implementation challenges such as weak supply-side readiness, limited scope for reallocation of existing resources and management not geared for accountability are too often ignored. Implementation and its monitoring is further hampered by the limitations of existing health information systems, which are often not ready to collect and analyse data on emerging interventions such as noncommunicable disease management. Among the countries of the WHO South-East Asia Region, those with better chances of executing their BPHSs have adapted their packages to their implementation, financing and monitoring capacities, and have considered the need for a modified service delivery model able to provide the agreed services.

Other considerations than: how much will universal health coverage cost?

Globally, countries have agreed to pursue the progressive realization of universal health coverage (UHC) and there is now a high level of political commitment to providing universal coverage of essential health services while ensuring that individuals are financially protected against high health spending. The aim of this paper is to help policy-makers think through the progressive realization of UHC. First, the pitfalls of applying global normative expenditure targets in estimating the national revenue required for UHC are discussed. Then, several recommendations on estimating national revenue are made by moving beyond the question of how much UHC will cost and focusing instead on the national health-care reforms and policy choices needed to progress towards UHC. In particular, costing exercises are recommended as a tool for comparing different service delivery options and investment in data infrastructure is recommended for improving the information needed to identify the best policies. These recommendations are intended to assist health policy-makers and international and national agencies who are developing country plans for the progressive realization of UHC.

À l'échelle mondiale, les pays sont convenus de poursuivre la réalisation progressive de la couverture sanitaire universelle, et l'on observe désormais un fort niveau d'engagement politique en faveur de la couverture universelle des services de santé essentiels en veillant à ce que les individus soient financièrement à l'abri de toute dépense de santé élevée. L'objectif de cet article est d'aider les responsables politiques à effectuer un examen minutieux en vue de la réalisation progressive de la couverture sanitaire universelle. Pour commencer, nous examinons les écueils liés à l'application d'objectifs de dépenses normatifs mondiaux au moment d'estimer le revenu national requis pour la couverture sanitaire universelle. Nous formulons ensuite plusieurs recommandations concernant l'estimation du revenu national, en dépassant la question du coût de la couverture sanitaire universelle pour nous concentrer sur les réformes nationales en matière de soins de santé et sur les choix politiques nécessaires pour faire progresser la couverture sanitaire universelle. Nous recommandons notamment de procéder à des exercices d'établissement des coûts pour comparer différentes options de prestation de services et d'investir dans des infrastructures de données pour améliorer les informations nécessaires à l'identification des meilleures politiques. Ces recommandations visent à aider les responsables des politiques de santé et les organismes internationaux et nationaux qui élaborent des plans nationaux pour la réalisation progressive de la couverture sanitaire universelle.

A nivel mundial, los países han acordado procurar la realización progresiva de la cobertura sanitaria universal (universal health coverage, UHC) y ahora existe un alto nivel de compromiso político para proporcionar una cobertura universal de los servicios sanitarios esenciales, al tiempo que se garantiza la protección financiera de las personas frente a los elevados gastos sanitarios. El objetivo de este documento es ayudar a los responsables de formular políticas a pensar en la realización progresiva de la UHC. Primero, se discuten las trampas en la aplicación de las metas globales de gastos normativos al estimar los ingresos nacionales requeridos para la UHC. Luego, se hacen varias recomendaciones sobre la estimación de los ingresos nacionales al ir más allá de la cuestión de cuánto costará la UHC y enfocarse en cambio en las reformas nacionales de salud y en las opciones de políticas necesarias para progresar hacia la UHC. En particular, se recomiendan ejercicios de cálculo de costos como herramienta para comparar diferentes opciones de prestación de servicios y se recomienda invertir en infraestructura de datos para mejorar la información necesaria con el fin de identificar las mejores políticas. Estas recomendaciones tienen por objeto ayudar a los responsables de formular políticas de salud y a los organismos internacionales y nacionales que están elaborando planes nacionales para la realización progresiva de la UHC.

Pooling financial resources for universal health coverage: options for reform.

Universal health coverage (UHC) means that all people can access health services of good quality without experiencing financial hardship. Three health financing functions - revenue raising, pooling of funds and purchasing health services - are vital for UHC. This article focuses on pooling: the accumulation and management of prepaid financial resources. Pooling creates opportunities for redistribution of resources to support equitable access to needed services and greater financial protection even if additional revenues for UHC cannot be raised. However, in many countries pooling arrangements are very fragmented, which create barriers to redistribution. The purpose of this article is to provide an overview of pooling reform options to support countries who are exploring ways to enhance redistribution of funds. We outline four broad types of pooling reforms and discuss their potential and challenges in addressing fragmentation of health financing: (i) shifting to compulsory or automatic coverage for everybody; (ii) merging different pools to increase the number of pool members and the diversity of pool members' health needs and risks; (iii) cross-subsidization of pools that have members with lower revenues and higher health risks; and (iv) harmonization across pools, such as benefits, payment methods and rates. Countries can combine several reform elements. Whether the potential for redistribution is actually realized through a pooling reform also depends on the alignment of the pooling structure with revenue raising and purchasing arrangements. Finally, the scope for reform is constrained by institutional and political feasibility, and the political economy around pooling reforms needs to be anticipated and managed.

La couverture sanitaire universelle (CSU) consiste à ce que l'ensemble de la population ait accès à des services de santé de qualité sans encourir de difficultés financières. Pour cela, trois fonctions de financement de la santé sont essentielles: le recouvrement des recettes, la mise en commun des fonds et l'achat de services de santé. Cet article s'intéresse à la mise en commun, à savoir le recueil et la gestion de ressources financières prépayées. La mise en commun permet de redistribuer les ressources afin d'offrir un accès équitable aux services nécessaires et d'améliorer la protection financière même en cas d'impossibilité de lever des recettes supplémentaires pour la CSU. Or, dans de nombreux pays, les mécanismes de mise en commun sont très fragmentés, ce qui fait obstacle à la redistribution. Cet article entend donner un aperçu des possibilités de réforme en ce qui concerne la mise en commun afin d'aider les pays qui cherchent à améliorer la redistribution des fonds. Nous présentons quatre grands types de réforme concernant la mise en commun et analysons le potentiel ainsi que les difficultés qu'ils présentent pour mettre un terme à la fragmentation du financement de la santé: (i) passage à une couverture obligatoire ou automatique pour tout le monde; (ii) fusion de différentes caisses afin d'augmenter le nombre de membres d'une même caisse ainsi que la diversité de leurs besoins et de leurs risques; (iii) interfinancement des caisses dont les membres ont des revenus faibles et des risques élevés en matière de santé; et (iv) harmonisation entre les caisses concernant, par exemple, les avantages, les modes de paiement et les tarifs. Les pays peuvent combiner plusieurs éléments de réforme. La réalisation du potentiel de redistribution grâce à une réforme de la mise en commun dépend aussi de l'alignement de la structure de mise en commun sur le recouvrement des recettes et les mécanismes d'achat. Enfin, l'étendue de la réforme est limitée par la faisabilité institutionnelle et politique, et l'économie politique relative à cette réforme de la mise en commun doit être anticipée et gérée.

La cobertura sanitaria universal (CSU) significa que todas las personas pueden acceder a servicios de salud de buena calidad sin experimentar dificultades financieras. Hay tres funciones de financiamiento de la salud que son fundamentales para la CSU: la recaudación de ingresos, la mancomunación de fondos y la compra de servicios de salud. Este artículo se centra en la mancomunación: la acumulación y gestión de recursos financieros prepagados. La mancomunación crea oportunidades para la redistribución de recursos que apoyan el acceso equitativo a los servicios necesarios y una mayor protección financiera, incluso si no se pueden recaudar ingresos adicionales para la CSU. Sin embargo, en muchos países los acuerdos de mancomunación están muy fragmentados, lo que crea barreras a la redistribución. El propósito de este artículo es proporcionar una visión general de las opciones de reforma de la mancomunación para apoyar a los países que están explorando formas de mejorar la redistribución de los fondos. Se describen cuatro grandes tipos de reformas de mancomunación y se discuten sus potencialidades y desafíos para abordar la fragmentación del financiamiento de la salud: (i) pasar a una cobertura obligatoria o automática para todos; (ii) fusionar diferentes fondos para aumentar el número de miembros del fondo y la diversidad de las necesidades y riesgos de salud de los miembros del mismo; (iii) subvención cruzada de fondos que tienen miembros con menores ingresos y mayores riesgos para la salud; y (iv) armonización entre los fondos, tales como beneficios, métodos de pago y tarifas. Los países pueden combinar varios elementos de reforma. La realización efectiva del potencial de redistribución mediante una reforma de la mancomunación depende también de la alineación de la estructura de la mancomunación con los acuerdos de recaudación de ingresos y compra. Por último, el alcance de la reforma se ve limitado por la viabilidad institucional y política, y es preciso anticipar y gestionar la economía política en torno a la reforma de la mancomunación.

An EMI-Based Clustering for Structural Health Monitoring of NSM FRP Strengthening Systems.

The use of fiber-reinforced polymers (FRP) in civil construction applications with the near-surface mounted (NSM) method has gained considerable popularity worldwide and can produce confident strengthening and repairing systems for existing concrete structures. By using this technique, the FRP reinforcement is installed into slits cut into the concrete cover using cement mortar or epoxy as bonding materials, yielding an attractive method to strengthen concrete structures as an advantageous alternative to the external bonding of FRP sheets. However, in addition to the two conventional failure modes of concrete beams, sudden and brittle debonding failures are still likely to happen. Due to this, a damage identification technology able to identify anomalies at early stages is needed. In this work, some relevant cluster-based methods and their adaptation to electromechanical impedance (EMI)-based damage detection in NSM-FRP strengthened structures are developed and validated with experimental tests. The performance of the proposed clustering approaches and their evaluation in comparison with the experimental observations have shown a strong potential of these techniques as damage identification methodology in an especially complex problem such as NSM-FRP strengthened concrete structures.

Financial protection analysis in eight countries in the WHO South-East Asia Region.

OBJECTIVE: To document the financial protection status of eight countries of the South-East Asian region and to investigate the main components of out-of-pocket expenditure on health care. METHODS: We calculated two financial protection indicators using data from living standards surveys or household income and expenditure surveys in Bangladesh, Bhutan, India, Maldives, Nepal, Sri Lanka, Thailand and Timor-Leste. First, we calculated the incidence of catastrophic health expenditure, defined as the proportion of the population spending more than 10% or 25% of their total household expenditure on health. Second, using World Bank poverty lines, we determined the impoverishing effect of health-care spending by households. We also conducted an analysis of the main components of out-of-pocket expenditure. RESULTS: Across countries in this study, 242.7 million people experienced catastrophic health expenditure at the 10% threshold, and 56.4 million at the 25% threshold. We calculated that 58.2 million people were pushed below the extreme poverty line of 1.90 United States dollars (US$) and 64.2 million people below US$ 3.10 (per capita per day values in 2011 purchasing power parity), due to out-of-pocket spending on health. Spending on medicines was the main component of out-of-pocket spending in most of the countries. CONCLUSION: A substantial number of people in South-East Asia experienced financial hardship due to out-of-pocket spending on health. Several countries have introduced policies to make medicines more available, but the finding that out-of-pocket expenditure on medicines remains high indicates that further action is needed to support progress towards universal health coverage.