Experimental study of the force transfer mechanism in transition zone between composite column and reinforced concrete column

The current EN 1992 provides structured information related to the design of reinforced concrete columns or reinforced concrete column beam connections. On the other hand, EN 1994 gives enough information on the design of composite columns but none of the current codes provide details about a possible transfer zone in the case of usage of RC and composite column solution. The current study tends to fill the gap between these two norms. In the current experimental campaign, carried out in the frame of the European research program SmartCoCo, it is presented as a calibration method for a tentative design method which has been elaborated by one of the authors based on theoretical strut and tie reasoning. The objective of the current paper is to present the results of the experiments and aims to validate the theoretical approach for calculating the force transfer mechanism in the transfer zone. The experimental campaign comprises of 4 columns and 4 column-beam connections, all of them being composed by a RC part and a composite. The tests are performed on vertical column, simply supported with a width of 350mm, length of 380 mm and a height of 3850 mm with a regular concrete quality (C25/30). This contribution describes the test specimens, summarizes their design, presents a selection of the most relevant results from analog and digital measurements and a short interpretation of the obtain results. We concluded from this set of tests that the new design method is able to explain the force transfer mechanism with a good accuracy and can therefore be considered as a suitable solution for designing practical cases. (Author)