DISSERTATION RC 14-3505 BEHAVIOR OF REINFORCED CONCRETE COLUMNS RETROFITTED BY EXTERNAL STEEL ANGLE COLLARS UNDER AXIAL COMPRESSION AND COMBINED AXIAL COMPRESSION AND REVERSED CYCLIC LOADING NAME : PAMUDA PUDJISURYADI ID NO. : 311 030 1005 SUPERVISOR : PROF. TAVIO, S.T. M.T. PH.D. CO-SUPERVISOR : PROF. IR. PRIYO SUPROBO, M.S. PH.D. GRADUATE DIVISION STRUCTURAL ENGINEERING PROGRAM DEPARTMENT OF CIVIL ENGINEERING FACULTY OF CIVIL ENGINEERING AND PLANNING SEPULUH NOPEMBER INSTITUTE OF TECHNOLOGY SURABAYA - INDONESIA 2017