EVALUATION OF DIFFERENT FIBER REINFORCED MORTAR AS RETROFITTING MATERIALS FOR RC COLUMNS

Abstract

This study is about the use of fiber reinforced mortar (FRM) as a jacketing material for
reinforced concrete (RC) columns. Presented in this paper are analyses of the test results of destructiveloading that were conducted to explore the applicability of different jacketing materials as retrofit to RC
columns. The jackets used to wrap RC columns were built of mortar mixed with different fibers. The fibers
considered were steel fibers and polymer fibers. A simple model based on material properties was used to
simulate the axial strength of the columns. The numerical model calculation results as well as the
experimental test results were used to assess the performance of the jacketing materials used. The
experimental part consisted of testing two sets of column specimens. The first set is wrapped with mortar
jackets reinforced with steel fibers and the second set is wrapped with mortar jackets reinforced with polymer
fibers with and without fly ash. The efficacy of the different FRM jackets as retrofitting materials was
assessed by calculating the effect of confinement. The calculation was accomplished by measuring the
maximum load of the retrofitted columns with jackets and then subtracting the load that can be carried by the
control specimens, that is, the column with the original cross section. The confining effect was used as the
basis in determining the confined compressive strength of concrete and then used to establish a model that
can simulate the axial strength of the columns. The results indicate that the FRM jackets are effective as
retrofitting material for RC column.