Interface slip control for CFRP-concrete composite beams

Carbon fibre reinforced polymer (CFRP) has been used frequently to retrofit concrete structures. Strengthening efficiency is related to the CFRP application process and the characteristics of the bonding agent. In this paper the mechanism of interface shear behaviour in CFRP to concrete beams is discussed considering previous test observations and mathematical models. This paper then discusses the consequences of introducing interface slip which reduces the integrity of the composite section, however improve ductility and delay debonding failure. The paper suggests that using softer bonding agent as well as setting limits on the interface slip could ensure acceptable serviceability and ductile behaviour

Assessing team learning practices in project/ design based learning approach

Team learning is considered as a constructive way for enhancing students learning in collaborative environment. It involves interaction between students through peer-to-peer learning, which makes students to be problem solver, an excellent communicator, a good reviewer and a manager. The School of Engineering at Xxx University practices project/design based learning as one of its learning and teaching approach. The project/design based learning process helps students to be self directed leaners which enhances the student learning outcomes towards attaining graduate career expected skills. An Overarching goal of this study is assessing the team learning experiences of cohort of students from third year civil undergraduate engineering in a project/design based learning approach at Xxx University. From the students’ experiences and views, this study will investigate and visualize the students choice of a unique team learning practice which enhances their learning outcomes in project/design based curriculum

Bond properties of rubber modified epoxy

In this paper, the bond integrity of unmodified and rubber-modified epoxy used for bonding the carbon fibre sheets to the hosting steel surface was investigated. The rigidity of the bonding agent is one of the factors that have a significant role in the premature failure (debonding) of this application. In order to overcome this issue, a series of experiments were conducted on the steel plates using the epoxy resin modified by CTBN and ATBN reactive liquid polymers, in addition to the unmodified epoxy resin. The interface between the carbon fibre matrix and the hosting surface is subjected to a longitudinal shear force for which the corresponding displacement is recorded. The shear stress-strain relationship for the tested specimen is plotted. The result shows that, the bond behaviour of modified epoxy using CTBN and ATBN reactive liquid polymers was improved in terms of ductility and toughness

Prevalence of Alcohol Consumption among University Students in Baghdad: A Cross-section survey from Iraq

Background: Alcohol consumption is a well-known public health problem, especially among university students. It was poorly studied in Middle East, especially in Iraq, due to religious and social taboos. This study conducted to throw a light on the prevalence of Alcohol consumption among university students in Baghdad. Subjects and methods: A survey conducted in three universities (Baghdad, Al-Mustansiriyah and Al-Nahrain) from Baghdad city, in the duration between January and May 2015.A semi-structured questionnaire form used to collect the data from 1435 university students. The sample selected by multistage random sampling technique with probability proportion to size. Results: The average age (range) of the studied sample was 19.8 (18 - 24) years; more than a half of them were females 760 (53%). Alcohol consumption was reported by 9.7% (95%CI: 8.2% - 11.2%) of the participants (19.7% males vs. 0.8% females). Heavy Alcohol consumption was reported by 12.2% of consumers. Male students living out of their families or relatives and those of medical group colleges found to be risk factors for Alcohol consumption (PR= 2.65, 95% CI: 1.72 - 4.1) and (PR= 2.72, 95%CI: 1.48 - 5.01) respectively. No significant relations showed between demographic characters of female students and Alcohol consumption. Conclusions: Usage of Alcohol was relatively prevalent among university students in Baghdad, in spite of religious and social barriers in Iraq. Family and college staff supervision and education of the students with meetings targeting health risks and sequels of Alcohol hazardous consumption are the effective ways to control this practice

Energy dissipation and geometry effects over stepped spillways

The energy dissipation process is the major significant point in the designof hydraulic structure. The dissipation of high energy on stepped weirsprevents any damage in the weir itself and channels the energy ownstream to reduce the stilling basin size. In this study, four physical models are used to evaluate the impact of adding end sills that have a quarter circle shape at step edges. The amount of energy loss on weirs under different flow regimes is investigated by experimental work. Stepped weirs have a suitable number of steps and two different ratios of the width to height (2.22, and 2.40). The scale of the physical models is 20:1. The outcomes of the dimensional analyses refer to the critical depth for flow in weirs to the height of step yc/h, the end sill radius, and the number of steps N are more effective parameters than others inthe energy loss process. Moreover, for small values of yc/h, the energydissipation is the greatest. Any increase in yc/h leads to a decrease in theenergy dissipation, while the energy dissipation increases with the number of steps (N)

Determination of discharge coefficient for flow over one cycle compound trapezoidal plan form labyrinth weir

Weirs are common structure to regulate discharge and flow control inwater conveyance channels and hydraulic structures. Labyrinth weirsconsidered one of economical and effective methods to increase the efficiency of weirs that crest length of weirs increase without a related increase in structure width. Therefore, flow discharge will be increased. Compared to use compound weir, there are some benefits including the simultaneous passage of floating materials such as wood, ice, etc. Also, sedimentations are pass through compound weir. The trapezoidal Labyrinth weir is one of the combined models. In present study 15 physical models that discussion effect changes sidewall angle of labyrinth weir on discharge coefficient of flow over and through the compound trapezoidal one cycle Labyrinth weir. Also, it is developed design curves with various shapes and configurations. The researchshowed here mainly objectives at determining the coefficient of discharge for flow-over trapezoidal labyrinth weir by performing tests at wide range of values of side wall angles (α) from 6° to 35° and compound linear weir to be compared