BEHAVIOUR OF FERROCEMENT COMPOSITE COLUMNS

Abstract

Ferrocement composite columns are used for prefabrication, repair-retrofitting and for casting insitu columns. Encasement of column end zones can be used to produce plastic hinges for seismic retrofitting. of columns. This is a theoretical and experimental investigation on the behaviour offerrocement encased concrete rectangular columns. The main thrust is on assessing the increase in strength and, ductility and stress-strain behaviour of ferrocement encased concrete columns due to passive confine-ment of concrete by the mesh wires. In this experimental programme a total of fifty one specimens were casted out of which twelve were cubes ofsize 150x150x150 and thirty nine were rectangular sections of size 300x150x300. They were tested to failure and the strains in longitudinal, horizontal and lateral directions were recorded for a load increament of ten tons each. The poisson's ratio was calculated. The experimental failure loads were compared with the theoretical failure loads. Ductility and toughness of meshed specimen was compared with the-plain specimens. They are found to increase with the number of mesh layers. Poisson's ratio was found to increase with increment of load i.e. passive confinement. The economic aspect was also analysed. Increase of number of mesh layers increases load carrying capacity upto a certain limit and then decreases. An increase in the cover thickness also decreases the load carrying capacity after a certain limit. The cracking and failure mode was also studied.