Mechanical properties of cotton fabric reinforced geopolymer composites at 200-1000 °C

Geopolymer composites containing woven cotton fabric (0–8.3 wt%) were fabricated using the hand lay-up technique, and were exposed to elevated temperatures of 200 °C, 400 °C, 600 °C, 800 °C and 1000 °C. With an increase in temperature, the geopolymer composites exhibited a reduction in compressive strength, flexural strength and fracture toughness. When heated above 600 °C, the composites exhibited a significant reduction in mechanical properties. They also exhibited brittle behavior due to severe degradation of cotton fibres and the creation of additional porosity in the composites. Microstructural images verified the existence of voids and small channels in the composites due to fibre degradation

Addressing multiculturalism for e-learning in higher education environments: A view of South East Europe

World Wide Web with the rapid development of Information and Communication Technologies (ICT) in HE has caused changes in the way teaching and learning is viewed increasing the diversity of the students' cohorts. Thus, students will increasingly be asked to interact with other students in multicultural environments for which they may be ill-prepared. This study identifies potential communication problems of students from South East Europe when they collaborate and co-operate in a synchronous chat and investigate if these problems can be related and attributed to differences arising from the diversity of students' cultural backgrounds. This study followed a mixed method approach to research by employing both quantitative and qualitative research methods of data collection and analysis was employed in a sample of 40 students. The results of this study showed that communication problems may arise between the participants from the investigated countries concerning the power distance cultural dimension. Although communication problems were identified, communication never broke down and the groups were all able to fulfil the goals of the activity more or less. The paper concludes that a sound appreciation or at least acknowledgment of the problems associated with diversity is essential for the survival of a multicultural teaching and learning activity not only for cultures with obvious differences such as between Chinese and American cultures that have already been proven, but for closer cultures of the same region (SEE Region) as well. This research is one of the few studies, which examines cultural communication problems between students coming from close cultures with common historical background. © 2011 IADIS

Seismic retrofit of R/C T-beams with steel fiber polymers under cyclic loading conditions

This paper presents results of an experimental study on seismic response of reinforced concrete (RC) T-beams with shear deficiencies strengthened with externally bonded steel fiber reinforced polymer (SFRP) strips. Seven cantilever RC beams were strengthened with externally bonded uniaxial SFRP strips in a U-shape configuration and were tested under cyclic loading conditions. The two main variables examined were the strip spacing and the use of anchoring system. Among the investigated anchoring systems, one was patented, and it is studied in the present manuscript. The examination of the results leads to the conclusion that the anchoring system has a significantly more pronounced effect on the performance of the beams and the mode of failure than the type or spacing of the strips. Furthermore, SFRP strips seem to have a great potential to be used for shear strengthening, especially since the use of mechanical anchoring systems drastically improves their performance. On the contrary, the lack of mechanical anchoring results in premature delamination of the strengthening system, and thus an undesirable SFRP material performance. © 2019 by the authors