Interfacial bond behaviour of GFRP bar in self-compacting fiber reinforced concrete

In an ongoing research project, discrete steel fibers are being used in a self-compacting concrete (SFRSCC) to replace completely steel stirrups for pre-fabricated beams reinforced longitudinally with pre-stressed glass fiber reinforced polymer (GFRP) and steel bars. To take the advantages of the non-corrodible character and high tensile strength of GFRP bars, the minimum SFRSCC cover needs to be determined in order to assure the adequate bond performance between these bars and the surrounding SFRSCC. Since bond of the longitudinal bars has a relevant impact on the cracking behavior of RC elements (crack opening and crack spacing), an extensive experimental program composed of pullout bending tests was carried out where the influence of the following parameters was assessed in terms of bond behavior: GFRP bar diameter, surface characteristics of the GFRP bars, bond length, SFRSCC cover thickness. The local bond law was derived from inverse analysis and it was used to define the slip mode of the constitutive law adopted for interface finite elements. These interface finite elements were used to assess the crack opening and crack spacing on SFRSCC beams flexurally reinforced with GFRP bars. This paper resumes the experimental program, describes the strategy to derive the local bond law and presents and discusses the numerical simulations

Shear capacity of HPFRC beams flexurally reinforced with steel and prestressed GFRP bars

This paper presents the relevant results from an experimental program to assess the shear capacity of high performance fiber reinforced concrete (HPFRC) beams flexurally reinforced with a hybrid system of passive steel and prestressed GFRP longitudinal bars. Three series of two beams with different level of prestressing were tested. The effect of prestressing level on the shear capacity of the beams was the main investigated parameter. The results showed an enhancement of the load carrying capacity, ductility and energy absorption with the increase of the prestress level. Based on the obtained results, the predictive performance of the analytical formulations of CEB-FIP Model Code 2010 and RILEM TC 162-TDF for the shear capacity of FRC beams was assessed. Both formulations seem appropriate for design purposes, but the CEB-FIP formulation predicts more conservative shear capacity. The experimental results demonstrated that the prestressing level has an effect on the shear capacity much higher than the one recommended by the codes

The Role of mathematical thought in the improvement of architecture students’ abilities on logical aspects of design

Background and Objectives: Architectural education as a challengeable subject is dependent on multiple variables. Since formation of an architect character and learning design abilities are related to this subject, it is so sensitive.  Historically, the role of mathematics and application of its different aspects in architectural design is indisputable. While recent decades have witnessed a high level of interaction between mathematics and architecture in the world, mathematics in architectural education in Iran is still being taught as a basic course through the lecture method. A great concern in learning architectural design is how to apply the basic courses in design process. Methods: According to the necessity of revising the role of mathematics in education of architectural design, and developing new approaches to apply mathematical thought in logical process of design, the present study aims to test an educational model in an environment consisting of test and control groups in the Basic Design 1 & 2 courses, using the proposed model of Lawson as well as quasi-experimental research method. The research subjects are selected among BA students of Islamic Azad University of Urmia (n=52). They provided logical solutions for design problems, using algebraic, arithmetic, geometric and symbolic aspects of mathematics. The subjects’ design abilities were evaluated by the performance measurement method based on verdict criteria. The researchers determined two groups of mathematical and architectural design measurement criteria. For design, the criteria included design conceptual quality, spatial and functional arrangement, form combination, presentation quality, creativity and final grade.  Findings: The final grades of four research projects executed in two studios were respectively for design 62.57,66.29, 71.30, 75.31 and for mathematics 64.99, 69.27, 71.72 and 74.9. The correlation between design and mathematics evaluation scores for project 1 of the studio 1 (ƿ=0.594) and project 2 of the studio 2 (ƿ=0.604) is independently obvious which indicates the strong combination between mathematics and design aspects in these projects. For the project 2 of the studio 1, the correlation was low (ƿ= 0.166). The possible explanation could be based on the lack of real materials application and the experiment of altering theory analysis to practical analysis. The correlation between design evaluation scores and mathematics application (ƿ=0.384) reveals a positive role for mathematical thought in developing logical solutions and general quality of design. Conclusion: Findings of this study directly refers to the correspondence between research assumptions and the verdict criteria. The findings indicate that students’ performance in test group is better than the students in control group in all criteria except the presentation. The best performance by subjects of the test group means that their ability in creating solution concept has much improved compared with the control group as a result of manipulating the independent variable which is the education method in this study. This improvement couldn’t be related to other unrelated independent variables, because these variables have been either controlled or their effect has been studied through the pre-test. Stated on the findings in analyzing the general quality of design, students provided complicated geometric patterns in their design as logical, creative and efficient solutions through realizing their mathematical principles. Acquiring and developing the design schema based on design problems in the Basic design studios results the improvement of the students’ ability in logical aspects of design.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Investigation of grapevine areas under climatic stress using high resolution atmospheric modelling: case studies in South Africa and New Zealand

High-resolution atmospheric simulations (500 m) were used to assess viticultural areas under climatic stress in South Africa and New Zealand. The potential areas in which high daytime temperature stress was likely to affect grapevine photosynthesis and grape composition were identified. Results indicated different diurnal temperature variations within the two areas due to synoptic and local environmental factors, often associated with the influence of terrain

Interacting entropy-corrected new agegraphic dark energy in Brans-Dicke cosmology

Motivated by a recent work of one of us [1], we extend it by using quantum (or entropy) corrected new agegraphic dark energy in the Brans-Dicke cosmology. The correction terms are motivated from the loop quantum gravity which is one of the competitive theories of quantum gravity. Taking the non-flat background spacetime along with the conformal age of the universe as the length scale, we derive the dynamical equation of state of dark energy and the deceleration parameter. An important consequence of this study is the phantom divide scenario with entropy-corrected new agegraphic dark energy. Moreover, we assume a system of dark matter, radiation and dark energy, while the later interacts only with dark matter. We obtain some essential expressions related with dark energy dynamics. The cosmic coincidence problem is also resolved in our model.Comment: 16 pages, no figure, accepted for publication in Gen. Relativ. Gra

EMQN best practice guidelines for genetic testing in dystrophinopathies.

Dystrophinopathies are X-linked diseases, including Duchenne muscular dystrophy and Becker muscular dystrophy, due to DMD gene variants. In recent years, the application of new genetic technologies and the availability of new personalised drugs have influenced diagnostic genetic testing for dystrophinopathies. Therefore, these European best practice guidelines for genetic testing in dystrophinopathies have been produced to update previous guidelines published in 2010.These guidelines summarise current recommended technologies and methodologies for analysis of the DMD gene, including testing for deletions and duplications of one or more exons, small variant detection and RNA analysis. Genetic testing strategies for diagnosis, carrier testing and prenatal diagnosis (including non-invasive prenatal diagnosis) are then outlined. Guidelines for sequence variant annotation and interpretation are provided, followed by recommendations for reporting results of all categories of testing. Finally, atypical findings (such as non-contiguous deletions and dual DMD variants), implications for personalised medicine and clinical trials and incidental findings (identification of DMD gene variants in patients where a clinical diagnosis of dystrophinopathy has not been considered or suspected) are discussed