Ferrocement as permanent formwork for reinforced concrete columns

Abstract

This study investigates the possibility of using ferrocement as a permanent fOllnwork for R.C. column. A total of twenty one columns wcre constructed and tested in this investigation. Twelve hollow ferrocement columns were madc by varying the mesh layers. Six of them were filled with reinforced concrete and the remaining six columns were filled with plain concrete. Three reinforced concrete columns and three plain concrete columns coated with ferroccment overlay containing double layer wire mesh were cast to compare the behaviour of pre-cast ferrocement formwork with that cast in place ferrocement overlay. Finally, three ordinary reinforced concrete columns were constructed and tested to compare thc performance with those enclosed in fenocement. All the columns have same cross-sectional area. The pre-cast fenocement hollow columns have been choscn as a substitute of wooden fOllllwork. For cement mOltar, a particular cement sand ratio 1:2 has been used throughout the investigation. The columns wcre fabricated in the laboratory, cured for 21 days and tested at 28 days using Universal Testing Machine. The study demonstrates that the use of ferrocemenl as a permanent formwork increases the cracking load and ultimate load of the composite system. The number of cracks and the width of cracks have bcen found to have reduced considerably due to the provision of ferrocement overlay. From the study it appears that permanent pre-cast ferrocement formwork could be a valuable proposition in construction under aggressive environments.