Structural performance and failure analysis of bubbledeck concrete slabs in construction

In this research paper, as the concrete material is eliminated from the locations situated around the middle of the cross-sections of bubbledecks (BDs), the BD type slabs are lighter than the traditional slabs. In the recent researches, the performance analysis (PA) is generally determined for the reinforced concrete (RC) structures with the moment-resisting frame (MRF) and dual systems. The dual system comprises mainly the MRF with shear wall of building under construction, as well as the flat slab having chiefly the BD system. In this paper, the evaluation of values of the performance and failure analysis of RC structures using BD system are submitted. We recorded a maximum load of 6.48, maximum stress of 75.00, macimum strain of 7.80, with minimum force of 0.83, while minimum slab length of 9.62 and lastly the maximum slab span of 27 for our bubbledeck concrete slab experiment in comparison with reinforced concrete slab to get the best results. The obtained results indicate that the lateral strengths of buildings increase by increasing the span length to story height ratio. Besides, the variations of the span length and the number of the story have more effects than the variation of the usage category buildings on the performance of structures. Furthermore, the span length has more effect than the number of stories in determining performance in an MRF. We observed that the bubbledeck concrete slabs are more lightweight and resistant in comparison with reinforced concrete

Application of external prestressing on the rehabilitation of reinforced concrete beams

Concrete structure experiencing any form of distress due to multiple reasons; need remedial, strengthening, and rehabilitation measures, if the structure is to attain serviceability and strength requirements of different elements. Further, the external welding reinforcement and prestressing of the reinforced concrete members have been proven to provide an effective strengthening approach. The prestressed concrete describes a type of concrete where internal stresses are instituted to counteract the multiple tensile stresses that are characteristics of service loading. In these concrete structures, cables, hard-drawn wires or bars of high strength alloy steel are employed as tendons to generate the counteracting stresses. The prestressed concrete is made up of an active combination of steel and concrete as these materials are traditionally stressed before the application of external loads. The prestressing technique has been comprehensively reviewed in numerous articles showing that it is more effective than the RCC structures. External prestressing is emerging as an essential component of prestressing as it is structurally attractive and economical. In external prestressing, the tendons are placed outside the member to improve the load-bearing capacity of the structures and their members. In this study, a beam exposed to various loading condition and distress is strengthened using external prestressing. The ultimate deflection and failure characteristics were evaluated using different loading scenarios; beam weight, live weight, and dead weight. The results for the prestressing analysis was provided for 10 and 20 strands

Modelling of earthquake repellent fibre reinforced concrete

Iraq is exposed to significant earthquakes since it is located in the Middle East, in southwestern Asia. Thus, buildings should be designed and constructed to resist seismic forces. This is not always the case. Most of typical fibre reinforced concrete residential buildings in Iraq are designed and constructed to resist gravity loads only without any considerations to earthquake resistance. It is generally assumed by designers that the seismic forces on low and high-rise buildings are low. The building frame structural system and infill walls are assumed to resist such loads. There has been no verification to these assumptions by designers. Several seismic evaluation methodologies exist over around the world including qualitative (empirical) and quantitative (analytical) methodologies. The most suitable seismic evaluation methodology to be used in Iraq is the analytical methodology of pushover analysis since it does not require an observed damage data from previous earthquakes. We have designed two building that could withstand the earthquakes and have been long lasting using the fibre reinforced concrete. The orientation of the long dimension of columns is an important factor in the seismic resistance of both buildings. The direction contains the long dimension of columns have an earthquake resistance larger than the other direction. Buildings having structural walls behave better than other buildings during earthquakes as long as the location of these walls does not form a horizontal irregularities

Effects of impulsive loading and deformation damage on reinforced concrete slabs during building construction

The effects of impulsive loading and deformation damage in reinforced concrete slabs were observed for analyzing the under-construction buildings for specific period of time. To fully harvest the structural capacity of building under constrcution with reinforced slabs sections exposed to combined actions, it is necessary to leave behind the simplicity of treating the verification of structural adequacy for normal stresses separately from that of shear stresses and instead fully exploit the advantages of choosing more efficient stress distributions. By exploring the vast possibilities of other statically admissible systems using optimization routines for deformation damage reduced to 20% from 80% in the work, the longitudinal reinforcement near the neutral axis in reinforced concrete can be utilized much more efficiently. In addition, by adhering to the interdependency constraints between normal and shear stresses in reinforced concrete a much more precise picture of the actual service stress state can be determined for impulsive loading and deformation damage where the maximum deformation and impulsive loading on RC-slab were observed at strain 91s≤t≤97s on RC-slab in the total simulation steps from 0s to 398s. There is therefore a need for a one- step, automated design tool capable of addressing such verifications holistically which was performed in the simulation of this study using Matlab R2019b. In this paper the theoretical basis and a free to use open-source design tool is presented, allowing for easy access to highly optimized designs capable of observing the impulsive loading and deformation damage on reinforced concrete materials to their limit

Modelling reinforced concrete beams for structural strengthening of buildings

Iraq has many damaged and vandalized building since it is located in the Middle East, in southwestern Asia. Reinforced concrete beams of normal weight and lightweight's beams were conducted. The study is also done on normal strength and high strength beams in each category. The reinforced concrete used were 0% and 0.75% in each category. The lengths of the concrete beams used were 35 mm and 60 mm in each category. The longitudinal reinforcement ratio in all the beams is kept at 1.46%. The effect of types of aggregates, length of concrete beams, and concrete compressive strength were studied and results were presented with regard to the shear and flexure strengths, beam load-deflection responses, mode of failure, stiffness, energy absorption, and ductility. Shear and flexural crack widths and cracking patterns of the beams were also presented. Reinforced concrete content of the beams was also discussed. The possibility of replacement of minimum concrete reinforcement for lightweight beams with reinforced concrete is discussed. The most efficient length of beams for this purpose was presented. The modeling of buildings were designed in ANSYS and the strengthening as well as reinforcement was being shown using the software tool for the buildings in Iraq

ANALYSIS OF CONCRETE FLEXURAL MEMBERS REINFORCED WITH FIBRE POLYMER

Analytical model is used in this paper to predict the load carrying capacity of structural concrete members under flexural and normal force which can be concentric or eccentric. The analysis is based on requirement of equilibrium and compatibility of strain in concrete and steel or FRP. The adopted model is based on the real stress strain diagrams for materials. In accordance with this model, the member cross section is covered by a mesh with the smallest cells. After that, stress or strain is determined in each cell and the integral is substituted by the process of summation to define the elements of stiffness matrix. The force vectors equations have nonlinear behaviour. However, in this model, these nonlinear equations are changed to linear equations using the iteration methods with fixity of secant modulus of elasticity in each iteration cycle. In this paper. FORTRAN computer program language is used to compute the force and strains vectors. The comparison between the analytical resaks obtained from the used model and experimental data for other researchers is performed. The analytical model is giving a reasonable agreement between the theoretical and experimental results

Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000–17: analysis for the Global Burden of Disease Study 2017

© 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license Background: Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea. Methods: We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates. Findings: The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1–65·8), 17·4% (7·7–28·4), and 59·5% (34·2–86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage. Interpretation: By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health. Funding: Bill & Melinda Gates Foundation

The unfinished agenda of communicable diseases among children and adolescents before the COVID-19 pandemic, 1990-2019: a systematic analysis of the Global Burden of Disease Study 2019

BACKGROUND: Communicable disease control has long been a focus of global health policy. There have been substantial reductions in the burden and mortality of communicable diseases among children younger than 5 years, but we know less about this burden in older children and adolescents, and it is unclear whether current programmes and policies remain aligned with targets for intervention. This knowledge is especially important for policy and programmes in the context of the COVID-19 pandemic. We aimed to use the Global Burden of Disease (GBD) Study 2019 to systematically characterise the burden of communicable diseases across childhood and adolescence. METHODS: In this systematic analysis of the GBD study from 1990 to 2019, all communicable diseases and their manifestations as modelled within GBD 2019 were included, categorised as 16 subgroups of common diseases or presentations. Data were reported for absolute count, prevalence, and incidence across measures of cause-specific mortality (deaths and years of life lost), disability (years lived with disability [YLDs]), and disease burden (disability-adjusted life-years [DALYs]) for children and adolescents aged 0-24 years. Data were reported across the Socio-demographic Index (SDI) and across time (1990-2019), and for 204 countries and territories. For HIV, we reported the mortality-to-incidence ratio (MIR) as a measure of health system performance. FINDINGS: In 2019, there were 3·0 million deaths and 30·0 million years of healthy life lost to disability (as measured by YLDs), corresponding to 288·4 million DALYs from communicable diseases among children and adolescents globally (57·3% of total communicable disease burden across all ages). Over time, there has been a shift in communicable disease burden from young children to older children and adolescents (largely driven by the considerable reductions in children younger than 5 years and slower progress elsewhere), although children younger than 5 years still accounted for most of the communicable disease burden in 2019. Disease burden and mortality were predominantly in low-SDI settings, with high and high-middle SDI settings also having an appreciable burden of communicable disease morbidity (4·0 million YLDs in 2019 alone). Three cause groups (enteric infections, lower-respiratory-tract infections, and malaria) accounted for 59·8% of the global communicable disease burden in children and adolescents, with tuberculosis and HIV both emerging as important causes during adolescence. HIV was the only cause for which disease burden increased over time, particularly in children and adolescents older than 5 years, and especially in females. Excess MIRs for HIV were observed for males aged 15-19 years in low-SDI settings. INTERPRETATION: Our analysis supports continued policy focus on enteric infections and lower-respiratory-tract infections, with orientation to children younger than 5 years in settings of low socioeconomic development. However, efforts should also be targeted to other conditions, particularly HIV, given its increased burden in older children and adolescents. Older children and adolescents also experience a large burden of communicable disease, further highlighting the need for efforts to extend beyond the first 5 years of life. Our analysis also identified substantial morbidity caused by communicable diseases affecting child and adolescent health across the world. FUNDING: The Australian National Health and Medical Research Council Centre for Research Excellence for Driving Investment in Global Adolescent Health and the Bill & Melinda Gates Foundation

Global, regional, and national age-sex-specific mortality and life expectancy, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

Background Assessments of age-specific mortality and life expectancy have been done by the UN Population Division, Department of Economics and Social Affairs (UNPOP), the United States Census Bureau, WHO, and as part of previous iterations of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Previous iterations of the GBD used population estimates from UNPOP, which were not derived in a way that was internally consistent with the estimates of the numbers of deaths in the GBD. The present iteration of the GBD, GBD 2017, improves on previous assessments and provides timely estimates of the mortality experience of populations globally. Methods The GBD uses all available data to produce estimates of mortality rates between 1950 and 2017 for 23 age groups, both sexes, and 918 locations, including 195 countries and territories and subnational locations for 16 countries. Data used include vital registration systems, sample registration systems, household surveys (complete birth histories, summary birth histories, sibling histories), censuses (summary birth histories, household deaths), and Demographic Surveillance Sites. In total, this analysis used 8259 data sources. Estimates of the probability of death between birth and the age of 5 years and between ages 15 and 60 years are generated and then input into a model life table system to produce complete life tables for all locations and years. Fatal discontinuities and mortality due to HIV/AIDS are analysed separately and then incorporated into the estimation. We analyse the relationship between age-specific mortality and development status using the Socio-demographic Index, a composite measure based on fertility under the age of 25 years, education, and income. There are four main methodological improvements in GBD 2017 compared with GBD 2016: 622 additional data sources have been incorporated; new estimates of population, generated by the GBD study, are used; statistical methods used in different components of the analysis have been further standardised and improved; and the analysis has been extended backwards in time by two decades to start in 1950.Background Assessments of age-specific mortality and life expectancy have been done by the UN Population Division, Department of Economics and Social Affairs (UNPOP), the United States Census Bureau, WHO, and as part of previous iterations of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Previous iterations of the GBD used population estimates from UNPOP, which were not derived in a way that was internally consistent with the estimates of the numbers of deaths in the GBD. The present iteration of the GBD, GBD 2017, improves on previous assessments and provides timely estimates of the mortality experience of populations globally. Methods The GBD uses all available data to produce estimates of mortality rates between 1950 and 2017 for 23 age groups, both sexes, and 918 locations, including 195 countries and territories and subnational locations for 16 countries. Data used include vital registration systems, sample registration systems, household surveys (complete birth histories, summary birth histories, sibling histories), censuses (summary birth histories, household deaths), and Demographic Surveillance Sites. In total, this analysis used 8259 data sources. Estimates of the probability of death between birth and the age of 5 years and between ages 15 and 60 years are generated and then input into a model life table system to produce complete life tables for all locations and years. Fatal discontinuities and mortality due to HIV/AIDS are analysed separately and then incorporated into the estimation. We analyse the relationship between age-specific mortality and development status using the Socio-demographic Index, a composite measure based on fertility under the age of 25 years, education, and income. There are four main methodological improvements in GBD 2017 compared with GBD 2016: 622 additional data sources have been incorporated; new estimates of population, generated by the GBD study, are used; statistical methods used in different components of the analysis have been further standardised and improved; and the analysis has been extended backwards in time by two decades to start in 1950

Measuring universal health coverage based on an index of effective coverage of health services in 204 countries and territories, 1990–2019 : a systematic analysis for the Global Burden of Disease Study 2019

Background: Achieving universal health coverage (UHC) involves all people receiving the health services they need, of high quality, without experiencing financial hardship. Making progress towards UHC is a policy priority for both countries and global institutions, as highlighted by the agenda of the UN Sustainable Development Goals (SDGs) and WHO's Thirteenth General Programme of Work (GPW13). Measuring effective coverage at the health-system level is important for understanding whether health services are aligned with countries' health profiles and are of sufficient quality to produce health gains for populations of all ages. Methods: Based on the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we assessed UHC effective coverage for 204 countries and territories from 1990 to 2019. Drawing from a measurement framework developed through WHO's GPW13 consultation, we mapped 23 effective coverage indicators to a matrix representing health service types (eg, promotion, prevention, and treatment) and five population-age groups spanning from reproductive and newborn to older adults (>= 65 years). Effective coverage indicators were based on intervention coverage or outcome-based measures such as mortality-to-incidence ratios to approximate access to quality care; outcome-based measures were transformed to values on a scale of 0-100 based on the 2.5th and 97.5th percentile of location-year values. We constructed the UHC effective coverage index by weighting each effective coverage indicator relative to its associated potential health gains, as measured by disability-adjusted life-years for each location-year and population-age group. For three tests of validity (content, known-groups, and convergent), UHC effective coverage index performance was generally better than that of other UHC service coverage indices from WHO (ie, the current metric for SDG indicator 3.8.1 on UHC service coverage), the World Bank, and GBD 2017. We quantified frontiers of UHC effective coverage performance on the basis of pooled health spending per capita, representing UHC effective coverage index levels achieved in 2019 relative to country-level government health spending, prepaid private expenditures, and development assistance for health. To assess current trajectories towards the GPW13 UHC billion target-1 billion more people benefiting from UHC by 2023-we estimated additional population equivalents with UHC effective coverage from 2018 to 2023. Findings: Globally, performance on the UHC effective coverage index improved from 45.8 (95% uncertainty interval 44.2-47.5) in 1990 to 60.3 (58.7-61.9) in 2019, yet country-level UHC effective coverage in 2019 still spanned from 95 or higher in Japan and Iceland to lower than 25 in Somalia and the Central African Republic. Since 2010, sub-Saharan Africa showed accelerated gains on the UHC effective coverage index (at an average increase of 2.6% [1.9-3.3] per year up to 2019); by contrast, most other GBD super-regions had slowed rates of progress in 2010-2019 relative to 1990-2010. Many countries showed lagging performance on effective coverage indicators for non-communicable diseases relative to those for communicable diseases and maternal and child health, despite non-communicable diseases accounting for a greater proportion of potential health gains in 2019, suggesting that many health systems are not keeping pace with the rising non-communicable disease burden and associated population health needs. In 2019, the UHC effective coverage index was associated with pooled health spending per capita (r=0.79), although countries across the development spectrum had much lower UHC effective coverage than is potentially achievable relative to their health spending. Under maximum efficiency of translating health spending into UHC effective coverage performance, countries would need to reach $1398 pooled health spending per capita (US$ adjusted for purchasing power parity) in order to achieve 80 on the UHC effective coverage index. From 2018 to 2023, an estimated 388.9 million (358.6-421.3) more population equivalents would have UHC effective coverage, falling well short of the GPW13 target of 1 billion more people benefiting from UHC during this time. Current projections point to an estimated 3.1 billion (3.0-3.2) population equivalents still lacking UHC effective coverage in 2023, with nearly a third (968.1 million [903.5-1040.3]) residing in south Asia. Interpretation: The present study demonstrates the utility of measuring effective coverage and its role in supporting improved health outcomes for all people-the ultimate goal of UHC and its achievement. Global ambitions to accelerate progress on UHC service coverage are increasingly unlikely unless concerted action on non-communicable diseases occurs and countries can better translate health spending into improved performance. Focusing on effective coverage and accounting for the world's evolving health needs lays the groundwork for better understanding how close-or how far-all populations are in benefiting from UHC