Deflection control for reinforced recycled aggregate concrete beams: Experimental database and extension of the fib Model Code 2010 model

Recycled aggregate concrete (RAC) has emerged as a viable solution for solving some of the environmental problems of concrete production. However, design guidelines for deflection control of reinforced RAC members have not yet been proposed. This study presents a comprehensive analysis of the applicability of the fib Model Code 2010 (MC2010) deflection control model to reinforced RAC beams. Three databases of long-term studies on natural aggregate concrete (NAC) and RAC beams were compiled and meta-analyses of deflection predictions by MC2010 were performed. First, the MC2010 deflection control model was tested against a large database of long-term tests on NAC beams. Second, a database of RAC and companion NAC beams was compiled and initial and long-term deflections were calculated using the MC2010 model. It was shown that deflections of RAC beams are significantly underestimated relative to NAC beams. Previously proposed modifications for MC2010 equations for shrinkage strain and creep coefficient were used, and new modifications for the modulus of elasticity and empirical coefficient β were proposed. The improved MC2010 deflection control model on RAC beams was shown to have equal performance to that on companion NAC beams. The proposals presented in this paper can help engineers to more reliably perform deflection control of reinforced RAC members.This is the peer-reviewed version of the article: N. Tošić, S. Marinković, and J. de Brito, ‘Deflection control for reinforced recycled aggregate concrete beams: Experimental database and extension of the fib Model Code 2010 model’, Structural Concrete, vol. 20, no. 6, pp. 2015–2029, 2019 [https://doi.org/10.1002/suco.201900035

Immunisation of migrants in EU/EEA countries: Policies and practices

In recent years various EU/EEA countries have experienced an influx of migrants from low and middle-income countries. In 2018, the “Vaccine European New Integrated Collaboration Effort (VENICE)” survey group conducted a survey among 30 EU/EEA countries to investigate immunisation policies and practices targeting irregular migrants, refugees and asylum seekers (later called “migrants” in this report). Twenty-nine countries participated in the survey. Twenty-eight countries reported having national policies targeting children/adolescent and adult migrants, however vaccinations offered to adult migrants are limited to specific conditions in seven countries. All the vaccinations included in the National Immunisation Programme (NIP) are offered to children/adolescents in 27/28 countries and to adults in 13/28 countries. In the 15 countries offering only certain vaccinations to adults, priority is given to diphtheria-tetanus, measles-mumps-rubella and polio vaccinations. Information about the vaccines given to child/adolescent migrants is recorded in 22 countries and to adult migrants in 19 countries with a large variation in recording methods found across countries. Individual and aggregated data are reportedly not shared with other centres/institutions in 13 and 15 countries, respectively. Twenty countries reported not collecting data on vaccination uptake among migrants; only three countries have these data at the national level. Procedures to guarantee migrants’ access to vaccinations at the community level are available in 13 countries. In conclusion, although diversified, strategies for migrant vaccination are in place in all countries except for one, and the strategies are generally in line with international recommendations. Efforts are needed to strengthen partnerships and implement initiatives across countries of origin, transit and destination to develop and better share documentation in order to guarantee a completion of vaccination series and to avoid unnecessary re-vaccination. Development of migrant-friendly strategies to facilitate migrants' access to vaccination and collection of vaccination uptake data among migrants is needed to meet existing gaps

An attempt to control natural focus of leptospirosis grippotyphosa by rodenticide - a long-term study [1977-2004]

The purpose of the study was to suppress a known natural focus of fi eld fever exerting an infl uence on animal hosts of leptospires – small terrestrial mammals (s.t.m.) by rodenticide. After repeated application of the zinc phosphide rodenticide, the s.t.m. were regularly live-trapped and checked for leptospirosis by dark-fi eld microscopy and culture of their renal tissue and serological examination. Isolated leptospira strains were typed by help of rabbit factor sera. The deratization infl uenced the s.t.m. structure considerably: the proportion of the dominant Microtus arvalis subjects – the main reservoirs of Leptospira kirschneri serovar Grippotyphosa – were gradually and substantionally reduced and, contrarily, the percentage of the potetial hosts subjects – Clethrionomys glareolus and Apodemus fl avicollis – rose decisively over time. Changes in culture and serological positivity for leptospirosis of s.t.m. have also been enregistered. The highest original infestation of M. arvalis have slowly but strongly decreased while that of C. glareolus and A. fl avicollis has increased decisively and reached its maximum within the last years of investigation. It is probable that these two animal species have undertaken the leading role in the maintenance of the natural focus of the fi eld fever. In other animal species analogous trends were not registered. Based on these long-term fi ndings, there exists the possibility to suppress only partially and temporarily the epizootic process of leptospirosis in a natural focus that can be desirable in some circumstances (building or free time activities, etc.)

Behaviour of concrete beam-column connections reinforced with hybrid FRP sheet

Modelling complex concrete column-beam connection with hybrid fibre reinforced plastic (FRP) reinforcement properly requires understanding of the behaviour of such component and supporting from some experimental data for model updating and refinement. This paper, through a comprehensive experimental work, investigates the behaviour of reinforced concrete frame specimens designed to represent the column-beam connections in plane frames. As a follow-up to the previous reported work, it focuses on details of experimental analyses, in particular, a comprehensive strain analysis. Results of the analysis show that designed hybrid FRP reinforcement greatly improve the stiffness and load carrying capacity of its concrete counterpart. It also delays the crack initiation at the joint through confinement due to FRP reinforcement. © 2002 Published by Elsevier Science Ltd

Discussion on "A simplified non-linear analysis of concrete frames"

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Utility of phylogenetic studies in the identification of Leptospira strains

A phylogenetic tree, which distinguishes between the serovars and serogroups of leptospires common in Central Europe was constructed using an established RAPD procedure together with digital reading and evaluation (using different computer software programs) of the generated amplified DNA patterns. The application of this procedure has revealed a consistent correspondence between serogroup and genotype (position in constructed tree) in 69 cases, and serovar and genotype in 72 cases, of wild strains of leptospires. There was an agreement between serovar and genotype in cases of strains of Grippotyphosa, Pomona, Mozdok, Arborea and Sorexjalna as well as between serogroup and genotype in cases of Australis, Bataviae and Sejroe. With the procedure used in this study, it was not possible to distinguish between reference strains of serovars Jalna, Bratislava and Lora (all serogroup Australis) as well as between serovars Icterohaemorrhagiae and Copenhageni (both of serogroup Icterohaemorrhagiae). In contrast to this, wild strains belonging to serogroup Sejroe were distributed between Polonica, Istrica, Saxkoebing and Sejroe serovars. Endemic strains of leptospires tested, were also distinguishable