Investigating the effects of FRP bars on the seismic behavior of reinforced concrete coupling beams

International audienceSometimes, it is necessary to install regular openings like windows or doors in the shear walls. Such openings require special reinforcement. There are several methods for reinforcing deep beams, one of which is the use of fiber reinforced polymer bars. In this study, an experimental work on a coupled shear wall has been used to mode the system by using finite element method with ABAQUS software. The finite element model was established based on part of the experimental study and verified with the other parts of the experimental results. The comparison shows good agreement. In the study, three different types of fiber reinforced polymer bars were considered in improving the mechanical and structural behavior of RC coupling beams. Results of the finite element analysis showed the superiority of the CFRP bars in improving seismic behavior of the coupled shear wall comparing to GFRP and BFRP

Invistigating the effects of frp bars on the seismic behavior of reinforced concrete coupling beams

Sometimes, it is necessary to install regular openings like windows or doors in the shear walls. Such openings require special reinforcement. There are several methods for reinforcing deep beams, one of which is the use of fiber reinforced polymer bars. In this study, an experimental work on a coupled shear wall has been used to mode the system by using finite element method with ABAQUS software. The finite element model was established based on part of the experimental study and verified with the other parts of the experimental results. The comparison shows good agreement. In the study, three different types of fiber reinforced polymer bars were considered in improving the mechanical and structural behavior of RC coupling beams. Results of the finite element analysis showed the superiority of the CFRP bars in improving seismic behavior of the coupled shear wall comparing to GFRP and BFRP

Environmental protection through nuclear energy

Environmental protection through implementation of green energies is progressively becoming a daily reality. Numerous sources of green energy were introduced in recent years. Although this process initially started with difficulties, it finally resulted in an acceleration and implementation of new green energy technologies. Nonetheless, new major obstacles are emerging. The most worldwide difficult obstacle encountered, especially for wind and photovoltaic electric power plants, is the not regular and predictable green energy production. This study proposes solutions designed to solve this unpleasant aspect of irregular production of green energy. The basic idea refers to the construction of specially designed nuclear power plants acting as energy buffers. Nuclear power plants, indeed, may behave as proper energy buffers able to work to a minimum capacity when the green energy (i.e., wind power or PV) is steadily produced (namely, when the energy generated by the turbines or PV panels is at full constant capacity) but that can also run at progressively increased capacities when the wind or solar energy production reduces or stops. The work get two major contributions: 1-propose to the achievement of an energy buffer using nuclear power plants (for the moment on nuclear fission); 2-shows some theoretical aspects important needed to carry out the reaction of the fusion

Interests, trust and security in US-Jordanian nuclear relations

This article explores the relationship between Jordan and the United States (US) in the field of nuclear energy cooperation. Since 2010 the Jordanian government has accelerated its plans for a nuclear energy program and has engaged with multiple partners around the world in order to agree terms for cooperation in technology exchange, monitoring, and the construction of infrastructure. Bilateral negotiations between the US and Jordan for a "123" nuclear cooperation agreement were underway by early 2008, but were suspended in 2011 without an agreement being reached. Jordanian nuclear energy policy has been spurred by energy security considerations (as it currently imports 97 percent of its energy needs) and the discovery of up to 120,000 tonnes of uranium ore in Jordan. At the same time, the US is primarily interested in management of nuclear technology proliferation. This work considers the perceptions of self and other in Jordanian and US policymaking in order to understand why bilateral cooperation has not materialized and what this means for nuclear proliferation in Jordan. This study finds that the US–Jordanian negotiations have been impeded by contradictory objectives and perceptions, and a "123" agreement is not likely in the short to medium term, but that development of Jordan’s nuclear energy program will likely continue regardless

Effect of the displacement rate and inclination angle in steel fiber pullout tests

This paper summarizes the results obtained in an experimental campaign on the effect of the displacement pullout rate and the inclination angle of the steel fiber pullout tests. For that purpose, specimens were obtained from a self-compacting concrete with a compressive strength of 86 MPa. In the experimental program, hooked-end steel fibers of 0.75 mm diameter and 60 mm length were used. Tests were executed with both hooked-end fibers, and smooth fibers obtained from the former by cutting the hooked end. For both type of fibers, their embedment length into concrete was 20 mm, and the influence of fiber inclination angle toward the load direction was investigated by adopting values of 0∘, 30∘ and 60∘. The tests were performed at displacement rates of 0.01, 0.1 and 1 mm/s. The results have shown that the peak pullout load increased with the inclination angle, in particular for the smooth series. Furthermore, higher displacement rates led to a higher energy absorption capacity for the pullout of the smooth fibers, while the energy absorption remained almost stable for hooked-end fibers.project BIA2015-68678-C2-1-R. M. Tarifa appreciates the financial support from the Department of Applied Mechanics and Project Engineering, UCLM (2018), and from the Programa propio de I+D+i de la Universidad Politécnica de Madrid para realizar estancias de investigación internacional igual o superior a un mes (2019), to do two stays at the University of Minho, Guimarães, Portugal. E. Poveda acknowledges the funding from the International Campus of Excellence CYTEMA and the University of Castilla-La Mancha, throughout Ayudas para estancias en universidades y centros de investigación en el extranjero en 2019 en el ámbito del plan propio de investigación susceptibles de cofinanciación por el Fondo Europeo de Desarrollo Regional (FEDER), Programa 010100021 to fund her stays in the University of Minho during 2018 and 2019, respectively. The authors thank the support of the Department of Civil Engineering and the Laboratory of the Structural Division (LEST), University of Minh

Glucose and Fatty Acid Metabolism in a 3 Tissue In-Vitro Model Challenged with Normo- and Hyperglycaemia

Nutrient balance in the human body is maintained through systemic signaling between different cells and tissues. Breaking down this circuitry to its most basic elements and reconstructing the metabolic network in-vitro provides a systematic method to gain a better understanding of how cross-talk between the organs contributes to the whole body metabolic profile and of the specific role of each different cell type. To this end, a 3-way connected culture of hepatocytes, adipose tissue and endothelial cells representing a simplified model of energetic substrate metabolism in the visceral region was developed. The 3-way culture was shown to maintain glucose and fatty acid homeostasis in-vitro. Subsequently it was challenged with insulin and high glucose concentrations to simulate hyperglycaemia. The aim was to study the capacity of the 3-way culture to maintain or restore normal circulating glucose concentrations in response to insulin and to investigate the effects these conditions on other metabolites involved in glucose and lipid metabolism. The results show that the system’s metabolic profile changes dramatically in the presence of high concentrations of glucose, and that these changes are modulated by the presence of insulin. Furthermore, we observed an increase in E-selectin levels in hyperglycaemic conditions and increased IL-6 concentrations in insulin-free-hyperglycaemic conditions, indicating, respectively, endothelial injury and proinflammatory stress in the challenged 3-way system

Pull-out Behaviour of Hooked End Steel Fibres Embedded in Ultra-high Performance Mortar with Various W/B Ratios

This paper presents the fibre-matrix interfacial properties of hooked end steel fibres embedded in ultra-high performance mortars with various water/binder (W/B) ratios. The principle objective was to improve bond behaviour in terms of bond strength by reducing the (W/B) ratio to a minimum. Results show that a decrease in W/B ratio has a significant effect on the bondslip behaviour of both types of 3D fibres, especially when the W/B ratio was reduced from 0.25 to 0.15. Furthermore, the optimization in maximizing pullout load and total pullout work is found to be more prominent for the 3D fibres with a larger diameter than for fibres with a smaller diameter. On the contrary, increasing the embedded length of the 3D fibres did not result in an improvement on the maximum pullout load, but increase in the total pullout work

Assessment of Woodcrete Using Destructive and Non-Destructive Test Methods

Utilizing solid wastes and industrial by-products as a partial replacement for raw materials has become an acceptable practice among researchers and scientists in the civil engineering field. Sawdust and wood shavings are not an exception; they are being used in concrete as a partial or total replacement for some of its constituents. The main goal of this research is to establish a relation between destructive and non-destructive testing for concrete containing wood shavings as a partial replacement of sand (woodcrete). With this type of material existing, thus the need to understand the behavior of such material becomes urgent and evokes the need to ease the process of the assessment and the evaluation of such materials and therefore provide more understanding of its behavior. In addition to the conventional concrete mix, five mixes of woodcrete were made by replacing fine aggregate by volume with wood shavings at different replacement levels varied from 5% to 50%. Cubic samples were tested at the age of 90 days using nondestructive tests (NDT), namely, rebound hammer test and ultrasonic pulse velocity test. Then, the specimens were tested using a conventional compressive test using a universal compression testing machine. Statistical analysis was performed to establish empirical relations between destructive and non-destructive results. The dynamic modulus of elasticity was calculated, and some formulas to estimate the (compressive) strength of woodcrete using NDT results were proposed and tested against experimental results and showed acceptable results