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TECHNICAL PAPER



         Each of Figures 10a to 10c compares the curves for specimens   REFERENCES
         with HSSCC and NSSCC jackets, for a particular percentage of
                                                                1.    Bett, B. j., Klingner, R. E., and jirsa, j.O. (1988). “Lateral
         jacket longitudinal reinforcement. It was found that the ultimate
         load and the corresponding deflection increased by 48% and   load response of strengthened and repaired reinforced
                                                                    concrete columns”. ACI Structural Journal, 85(5), 499-508.
         73%, respectively, even for the lowest amount of additional steel
         of 0.38%. The initial stiffness for HSSCC and NSSCC specimens   2.    Ersoy, U., Tankut, A. T., and Suleiman, R. (1993). “Behaviour
                                                                    of jacketed columns”. ACI Structural Journal, 90(3), 288-
         with a certain amount of steel was found to remain almost same,
         because of the thin jackets.                               293.
                                                                3.    Rodriguez, M., and Park, R. (1994). “Seismic load tests on
                                                                    reinforced concrete columns strengthened by jacketing”.
         8.  SUMMARY AND CONCLUSIONS
                                                                    ACI Structural Journal, 91(2), 150-159.
         The application of HSC as a jacket material to strengthen shear-  4.    Fukuyama, K., Higashibata, Y., and Miyauchi, Y. (2000).
         critical RC columns was examined in the present research. Two   “Studies on repair and strengthening methods of
         selected strengths of SCC equal to 69.1 MPa (high-strength)   damaged reinforced concrete columns”. Cement and
         and 43.7 MPa (normal-strength) were used to jacket 12 beam-  Concrete Composites, 22(1), 81-88.
         column specimens of shear span-to-effective depth ratio equal   5.    Bousias, S. N., Spathis, A. L., and Fardis, M. N. (2007).
         to 1.7. They had three different amounts of jacket longitudinal   “Seismic retrofitting of columns with lap spliced smooth
         tension reinforcement, 0.38%, 1.54% and 3.83%. There were no   bars through FRP or concrete jackets”. Journal of
         ties in the test regions to avoid their influence in shear capacity.   Earthquake Engineering, 11(5), 653-674.
         The details of materials used, specimen preparation, conducted   6.    Vandoros, K. G., and Dritsos, S. E. (2008). “Concrete jacket
         tests and test results are discussed in this paper. The salient   construction detail effectiveness when strengthening RC
         observations from the conducted tests and conclusions from the   columns”. Construction and Building Materials, 22(3), 264-
         study are as follows.                                      276.
                                                                7.    Kaliyaperumal, G., and Sengupta, A. K. (2009). “Seismic
         (a)  Under single point lateral loading, the failure of all the
         specimens were due to diagonal cracking of the jacket concrete   retrofit of columns in buildings for flexure using concrete
                                                                    jacket”. ISET Journal of Earthquake Technology, 46(2), 77-
         as well as the inner concrete. This was as per the deliberate   107.
         choice of designing the specimens for shear failure.
                                                                8.    Kaliyaperumal, G., and Sengupta, A. K. (2014). “Seismic
         (b)  The use of HSSCC in the jacket indeed increased the shear   behaviour of concrete jacketed columns in buildings”.
         capacity of the retrofitted specimens substantially, based on the   Proceedings of the Institution of Civil Engineers, 167(SB9),
         increased diagonal cracking strength of the added concrete.   534-543.
         There was no delamination of the jacket made of HSSCC under   9.    Cheong, H. K., and MacAlevey, N. (2000). “Experimental
         the static monotonic loads. For a member with ties, the diagonal   behaviour of jacketed reinforced concrete beams”. Journal
         compressive strength of the added concrete will be more with   of Structural Engineering, 126(6), 692-699.
         the use of HSSCC.                                      10.   Altun, F. (2004). “An experimental study of the jacketed
                                                                    reinforced-concrete beams under bending”. Construction
         (c)  The lateral load versus mid-span deflection behaviour   and Building Materials, 18(8), 611-618.
         curves of the specimens with two types of concrete revealed
         that for shear-critical specimens, the stiffness of both the types   11.   Chalioris, C. E., Papadopoulos, C. P., Pourzitidis, C. N.,
                                                                    Fotis, D., and Sideris, K. K. (2013). “Application of a
         remained almost the same. Hence, the use of HSSCC in thin   reinforced self-compacting concrete jacket in damaged
         jackets is not detrimental in attracting higher shear demand as   reinforced concrete beams under monotonic and repeated
         compared to the use of NSSCC.                              loading”. Journal of Engineering, Vol. 2013, Article ID
                                                                    912983.
         (d)  The post-yield ductility of the jacketed specimens was
         not evident in absence of the ties in the test regions. Other   12.   Raval, S. S., and Dave, U. V. (2013). “Effectiveness of
                                                                    various methods of jacketing for RC beams”. Procedia
         specimens tested with ties showed limited ductility even under
         shear failure  [19] .                                      Engineering, 51, 230-239.
                                                                13.  Takiuti, A. R., Hanai, j. B., and Mirmiran, A. (2008).
         The study can be further extended to test specimens under   “Preloaded RC columns strengthened with high-strength
         reversed cyclic loading using displacement controlled actuators,   concrete jackets under uniaxial compression”. Materials
         to investigate the degradation of strength for jackets with HSC.   and Structures, 41(7), 1251-1262.


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