000 03908nas|a2200385 i 4500
005 20260817172218.0
008 150900s2000 th u m rtt 0| a1eng d
035 _a.b11807829
099 9 _aAIT Thesis no.ST-00-10
100 1 _aHe, Kun
245 1 0 _aCarbonation and corrosion of reinforcement bar in concrete with different ingredients
260 _aBangkok :
_bAsian Institute of Technology,
_c2000
300 _a121 leaves
490 1 _aThesis ;
_vno. ST-00-10
500 _aA thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Civil Engineering
502 _aThesis (M. Eng.) - Asian Institute of Technology, 2000
520 _aThis study is concerned with the effects of mortar composition on carbonation and corrosion rate. The following condition are selected in this study, 1: 0. 7: 4.5 of cementious: water: sand mix portion, 0%, 15% and 30% fly ash content as the replacement of OPC and 0%, 0.5% and 2% chloride ion by the addition of calcium chloride, 9 types of specimens are constituted according to the designed mix composition. The specimens with steel bar cured in control room are used for the corrosion experiment, and the specimens without steel bar curing water tank are used for the carbonation experiment. In addition, half numbers of specimens with steel bar are subjected to pre-carbonation in order to observe the difference of corrosion between carbonation and non-carbonation. The specimens were exposed at AIT in Thailand for two months and four months. The measurement of carbonation rate, weight loss, surface roughness and visual observation are conducted in this experiment. The results showed that high pressures carbon dioxide dramatically accelerates the carbonation process. Carbonation depth increases with time, it was bigger for the specimens with fly ash than without fly ash, and it increased with the increase of the addition of chloride ion in mortar. The morphology of corroded steel bar exhibited the black corrosion product Fe304.3H20 below the red-brown corrosion products Fe(OH)3, and the scale of corrosion product was founded in relative serious case. Weight loss is bigger for the specimens with fly ash than without fly ash, weight loss increases with the order from 0%, 0.5% to 2%, weight loss increases with exposure period. At 0% and 0.5% chloride ion level, the carbonated specimens have slightly bigger weight loss than non-carbonated ones, at the 2% chloride ion level, the serious corrosion occurs in non-pre-carbonation specimen containing 30% fly ash for two and four months exposure, 15% fly ash for four months exposure. The serious roughening of surface on the corroded steel bar takes place in higher chloride ion concentration, and higher fly ash content. These results show that very severe pitting corrosion occurs under coexistence of high fly ash content and high Cl- concentration.
650 0 _aReinforced concrete
_xCorrosion
700 1 _aNii, Kazuyoshi,
_eChairperson
700 0 _aPichai Nimityongskul,
_eExamination Committee
700 1 _aTakewaka, Koji,
_eExamination Committee
710 2 _aGovernment of Japan,
_eScholarship donor
810 2 _aAsian Institute of Technology.
_tThesis ;
_vno. ST-00-10
856 _3Full-Text
_uhttp://203.159.5.9/ait-thesis/detail.php?q=B06835
907 _a.b11807829
_bmnait
_cu
902 _a240331
998 _b0
_c000915
_dm
_ea
_fu
_g0
945 _lmnait
945 _lmnarc
942 _c22
942 _c40
909 _aBarcode : 30050120747125
_bCREATED : 2014-05-30
_cRECORD # : i12804903
_dLPATRON : 1027215
_eLCHKIN : 2016-11-11
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 1
_jTOT RENEW : 1
909 _aBarcode : 30050160102082
_bCREATED : 2016-04-21
_cRECORD # : i1294371x
_dLPATRON : 0
_eLCHKIN : -
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 0
_jTOT RENEW : 0
999 _c15230
_d15230