Experimental behavior of scc with nano-silica andnumerical analysis of cfst composite columns usingscc as an infill

Composite sections are being increasingly popular in constructionindustry. Among them, concrete lled steel tube (CSFT) members areprimarily suited for dierent structural applications. This compositesystem uses the compressive strength of the concrete core as well asthe strength, stiness and connement eect of the surrounding steeltube. In this thesis, rstly, an experimental study on the behavior ofself- compacting concrete (SCC) containing high volume of nano- silica(up to 6%) and 'y ash (up to 75%) was conducted. Secondly, anumerical investigation on short CFST columns made with SCCproduced in the rst part of study was carried out. The structuralresponse of the composite columns were evaluated under the eect ofcompression up to failure. Two design codes such as AmericanConcrete Institute (ACI) and Eurocode 4 (EC4) were used forcalculating the ultimate axial strength of CFST columns lled with SCC.The 16 SCC mixtures were studied and their concrete compressivestrength results at two dierent testing ages were used to get the code predicted ultimate axial strength of the composite columns. Theexperimental and numerical results were given and discussedcomparatively.