Effect of sleeve length on deformation properties of grouted splices
Tests on 12 grouted splices were performed to investigate their deformation properties under tensile loading. Test variables included diameter and type of spliced bars and the size of splicing sleeves. Finite element method based models of the splices were built, verified and used to investigate the effect of sleeve length on the deformation properties of the grouted splices. The sleeve length significantly affected the failure modes and further affected the splices’ deformation properties. A recommendation was proposed to maximize deformation properties of a specific splice by using a critical sleeve length associated with failure mode of bar fracture.
Non-proprietary bar splice sleeve for precast concrete construction
Abstract Over the last few decades, the use of precast concrete components have been significantly increasing in building and bridge construction due to their quality, durability, and speed of construction. Precast components need to be fully connected to ensure the integrity, serviceability, and durability of the completed structure. Several proprietary grout-filled sleeves are currently being used to splice reinforcing bars of the adjacent precast components. These sleeves require very tight tolerances in precast production to ensure the alignment of the spliced bars, which usually results in using larger and more costly sleeves than needed. The objective of this paper is to introduce a non-proprietary bar splice sleeve that accommodates current production tolerances in addition to being economical and easy to produce. The design method of the proposed splice sleeve and the analytical investigation conducted using FE analysis are discussed. The experimental investigation conducted using two alternatives of the proposed bar splice sleeve is presented. Eighteen specimens for splicing #8 and #9 bars were tested using different sleeve lengths. Test results indicated that the proposed bar splice sleeve have adequate capacity to fully develop reinforcing bars while being simpler to use and more economical than current proprietary splice sleeves.
Students as promoters of rural extension in aquaculture in the Marajó archipelago, Pará, Brazil
Aquaculture is the creation of aquatic organisms. An expanding activity, being of great importance its approach in rural extension. Thus, the objective of this study was to analyze the contribution of extension activities in aquaculture in the professional training of students in Marajó, Amazon, Brazil. The project “Technology transfer through training and technical assistance for tambaqui breeders, Colossoma macropomum, in the archipelago of Marajó/PA” was developed by 10 technician and under graduate students from rural education course and the technical course in aquaculture from the Federal Institute of Education, Science and Technology of Pará (IFPA) Campus Breves, in the city of Curralinho. They participated in the stages of data collection in aquaculture enterprises, training for producers and monitoring of aquaculture production, acting as researchers, instructors and extension workers, respectively. The duration of the project was from August 2019 to March 2020. At the end of the project, a questionnaire was applied to the students involved. The results showed that the aquaculture extension activities developed were relevant and significant, for the construction of knowledge in a mutual way between those involved (students and aquaculture producers). The acquired experiences will substantiate and subsidize the professional practice of these students in a concrete and effective way. In conclusion, the extension project represents an excellent tool in the teaching-learning process for students.