Condition Assessment of Bridges by NDT Methods

Transcription

1 Coto Assessmet of Brges by NDT Methos 1 A.G. More, 2 V.M. Bogar 1 Stuet M.Tech, 2 Assstat Professor, Apple Mechacs Departmet, Govt. College of Egeerg, Kara, Maharashtra, Ia Abstract - As a structure becomes oler a oler t shows wear a tear ue to ageg, exposure to weather or evromet a structurally uplae mofcatos whch affect the health of the structure sgfcatly. Hece coto assessmet of structure s ecessty for esurg that the structure a ts premses are safe a uer o rsks coto. The ee of coto assessmet s also for mateace a repars of exstg structures whose lfe has exceee the age of 30 years so as to avo ay mshaps a save valuable huma lfe. I ths paper coto assessmet for brge structure has bee carre out usg fferet No-estructve test methos lke surface ultrasoc pulse velocty test, rebou hammer, half cell potetal methos a cover meter. DER ratg techque s use to f out the coto of brge terms of Coto Iex (CI). Iex Terms Coto Assessmet, No -estructve testg, DER ratg, coto-iex. I. INTRODUCTION Preset metho of coto assessmet of structure s Structural health motorg (SHM). SHM has bee a subject of major teratoal research recet years. The research ths subject covers sesg, commucato, sgal processg, ata maagemet, system etfcato, formato techology, etc; The curret challeges for brge structural health motorg are beg etfe as strbute a embee sesg, ata maagemet a storage, ata mg a kowlege scovery, agostc methos, a presetato of useful a relable formato to brge owers/maagers for ecso makg o mateace a maagemet. Structural health motorg ca be mae wth NDT methos to prove formato for structural performace. There are varous methos of o estructve testg. Such as: NDT Methos: Vsual Ispecto Ultra Soc Pulse Velocty (USPV) Test Cover Meter. Rebou Hammer Test. Cocrete Core Stregth Half Cell Potetometer Carboato Test Chemcal Aalyss : (ph, Cl, SO3) II. METHODOLOGY FOR FINDING CI Cotoal Rakg O the bass of vsual observato a -stu tests, It s umercal ex of amage level betwee 0 to 100; 0 beg the worst a 100 beg the best coto of workg. Ths s use to covert physcal state of structure to quattatve values. Ths ex serves as gueles for structure for further aalyss. The coto ex evelope by Gleema a Stcker s use to covert physcal state of structure to qualtatve values as show table 1. Purpose a Sgfcace of Coto Rakg/Coto Ratg Coto rakg evaluato work s geerally performe for the followg purpose, To eterme the structural stablty a tegrty of a structure or selecte elemets. To eterme whether extra stregtheg s requre for the structure. To eterme servce lfe of structure. To evaluate structural problem arse ue to uusual loag, poor costructoal practces As per Wakhae a Laage (2012), IJEDR Iteratoal Joural of Egeerg Developmet a Research ( 191

2 Table1. Coto Iex Scale Zoe Coto Iex Coto Descrpto Excellet: No otceable efects. Some agg or wear may be vsble Very Goo: Oly mor eterorato or efects are evet Goo: Some eterorato or efects are evet, but fucto s ot sgfcatly affecte Far: Moerate eterorato. Fucto s stll aequate Poor: Serous eterorato at least some portos of the structure. Fucto s aequate Very Poor: Extesve eterorato. Barely Fuctoal. 0-9 Fale: No loger fuctos, Geeral falure or complete falure of major structural compoet. Recommee Acto Immeate acto s ot requre Ecoomc aalyss of repar alteratves s recommee to eterme approprate acto Detale evaluato s requre to eterme the ee for repar, Rehabltato or recostructo. Safety evaluato s recommee. III. NONDESTRUCTIVE EVALUATION RATING Noestructve testg s a techology that ee ot estroy the reforce cocrete structure but ca assess the coto of the reforce cocrete. Here No estructve testg methos aopte are as follows: Base o NDT testg results, cotoal rakg of the brges s calculate. The formula for cotoal rakg s base o pot eucto formula a weght average metho. Brge score eucto pots s subtracte from perfect score of 100, a cotoal ex s assge to each specte tem. I ths approach each elemet s specte by NDT a assesse terms of three aspect of efect.e. Degree (D), Extet (E) a Relevacy (R) usg 0 to 4 rakg scheme. Degree (D) s efe as the severty of the elemet efect uer coserato (f the elemet has more tha oe efect the choose the most server efect for rakg). Extet (E) s the extet to whch the efect occurs over the area of the brge elemet. Each of ths parameter s combe the prortzato moule to eterme a prorty rakg of brges requrg repar. After NDT specto, the elemet coto ex (CI) for each compoet of the brge s calculate as follows. D E a 4 4 Ic The the cotoal ex of brge s calculate by: a max R (1) I c = Coto ex of each compoets CI I c 1 1 w, w where 1 w 100 Where, (2) IJEDR Iteratoal Joural of Egeerg Developmet a Research ( 192

3 I = 1~ ( s the umber of compoets of brge) A = Parameter eterme by the mportace of the brges (usually the value of a rages tram 1 to 2). W = Weghtgs of brge compoets. (Assume that the total weght of a all compoet group value s 10, 100, so o, t s ot uque). Table 2: DER Ratg Scale for Vsual Ispecto Ratg D No Such tem Goo Far Poor Severe E Caot be specte <10% <30% <60% <hgh R Caot be ece Mor Small Meum Hgh Table 3: Schmt hammer test for cocrete compresso stregth D value Ratg Test Results 0 No Such Item (P a P t are the esg a test results of the cocrete compresso stregth) D-value ratg Table 4: Rebar locator for cover thckess P p t P t p t p 0.75P p p Test Results 0 No such tem De Dt De Dt 0. 75De De Dt 0. 5De 4 Dt 0. 25De p t p (De a Dt are the esg cocrete cover thckess a -stu cocrete cover thckess) D-value ratg Table 5.Corroso test Test Results 0 No such tem 1 V2 Ve 2 V V Ve V2 3 V1 Ve V2 0. 5V 4 V2 V1 (Ve s the measure electrcal potetal; V1 =-350mV, V2 =-200mV whe electrcal soluto s CuSO4, whle V1 = -90mV, V2 = -240mV whe electrcal soluto s AgNO3) IV. CASE STUDY IJEDR Iteratoal Joural of Egeerg Developmet a Research ( 193

4 The Sambhaj Brge s a RCC arch brge o Jayat Nalha locate at Shahupur, Kolhapur (Maharashtra). Brge s havg two RCC pers a RCC Abutmets at es a total 3 Spas. The Brge was costructe the Year 1970 as per the recors of Kolhapur Mucpal Corporato. The Brge Legth s approxmately M. wth carrageway wth of M. Spa legth betwee Abutmets to Per s 6.60 M. The epth of RCC Arch Rg s 350 MM. Steel Ralg s prove of heght 1.00 M. Servce les are avalable parallel to the legth of brge throughout o oe se. Spouts are ot prove at both ses of Carrageway to ra out Storm Water. Lghtg arragemets & Footpaths are prove throughout the legth of the Brge. Fg.1 Elevato of Sambhaj Brge Fg.2 Sofft Detal Pla of Sambhaj Brge Coto ex s eterme by NDT evaluato by DER Ratg approach for all the compoet/ elemet of Brge Assume, Desg stregth of cocrete (M 25)=30 N/mm 2 Cocrete cover for Per, D c=50mm Cocrete cover for Abutmet, D c=50 mm Cocrete cover for slab, D c=50 mm Parameter a s relate to mportace of brge = 1.2 1) Coto Rakg / Coto Iex for Per- P1 (Ic1) P =30 N/ mm 2, a=1.2, D c= 50mm Value of E a R from DER Ratg Vsual specto table 2, E=2 a R=2 IJEDR Iteratoal Joural of Egeerg Developmet a Research ( 194

5 ) Cocrete comp. stregth measure by rebou hammer test = P t = 39 N/mm 2 From table 3, D = 1 ) Avg. Cocrete cover measure by Cover meter = D c= 50 From table 4, D = 1 From above two values of D, D max= 1 Hece, I c1= ) Coto Rakg / Coto Iex for Abutmet A1 (Ic2) P =30 N/ mm 2, a=1.2, D c= 50mm Value of E a R from DER Ratg Vsual specto table 2, E=2 a R=2 ) Cocrete comp. stregth measure by rebou hammer test = P t = 40 N/mm 2 From table 3, D = 1 ) Avg. Cocrete cover measure by Cover meter = D c= 50 From table 4, D = 1 From above two values of D, D max= 1 Hece, I c1= ) Coto Rakg for Sofft (I C3) P =30 N/ mm 2, a=1.2, D c= 50mm Value of E a R from DER Ratg Vsual specto table 2, E=3 a R=4 ) Cocrete comp. stregth measure by rebou hammer test = P t = 13.5 N/mm 2 From table 3, D = 4 ) Avg. Cocrete cover measure by Cover meter = D c= 50 From table 4, D = 1 ) Avg. corroso measure by half cell potetometer = V e = From table 5, D = 4 From above two values of D, D max= 4 Hece I c3= 12.5 Fally, Coto ex (CI) of brge s CI I c 1 1 w w, where 1 w 100 CI =55.21 From Table 1 of coto ex scales, for CI =55.21, whch les betwee CI = 55 to 69, t meas that coto of brge s goo, some eterorato at some portos of the structure. Table No. 6 Sr. No Structural Member CI (DER Metho) 1 Per Abutmet Sofft For total brge V. CONCLUSIONS Base o vsual specto a o estructve testg, followg coclusos are mae: 1. Coto ratg s a sutable metho for assessg the overall coto of cocrete structures because the coto of IJEDR Iteratoal Joural of Egeerg Developmet a Research ( 195

6 each compoet ca be motore cotuously. 2. Rebou hammer test, Cover Meter, Half cell potetometer a varous other NDT methos are useful evaluatg the structural stablty of structure. 3. The rakg assessmet of brge cosere here s carre out usg rebou hammer, Cover meter, half cell potetometer a ts C.I. =55.21, whch mples coto of brge s goo but there s requremet of ecoomc aalyss of repar. REFERENCES [1] Mg-Te Lag, Ch-Mg L, a Ch-Jag Yeh, Comparso Matrx Metho A ItsApplcatos To Damage Evaluato ForExstg Reforce Cocrete Brges, Joural of Mare Scece a Techology, Vol. 11, No. 2, pp (2003) [2] Raja L. Wakhae, Amarsh B. Laage No-estructve Testg of Cocrete Structures Kara Rego, R. Ncole, Procea Egeerg 51 ( 2013 ) 8 18 [3] Sallehu Shah Ayop, Rosl Mohama Z,Mohamma Ismal Coto Assessmet of Mare Structures Usg Fuctoal Coto Iex Approach Malaysa Joural of Cvl Egeerg 18(2) (2006) [4] Rash, M. & Gbso, P., A methoology for brge coto evaluato, Joural of CvlEgeerg a Archtecture, 6 (9), (2012). [5] F. Masoum, F. Akgül, a A. Mehrabzaeh Coto Assessmet of Reforce Cocrete Brges by Combe Noestructve Test Techques IACSIT Iteratoal Joural of Egeerg a Techology, Vol. 5, No. 6, December 2013 [6] Rajmoha Rajragava, Dr.Kamal Karuaaa, Brge Mateace Strategy For Sr Laka Through Aalytcal Herarchy Process A Structural Relablty Theory, Iteratom coferce o sustaabble ergegy & bult evoremet, 2017 [7] Bhaaura, S. S., Gupta, M. C., I Servce Durablty Performace of Water Taks, ASCE Joural of performace of costructe facltes 20(2), p [8] Sato, M. Sha, K. C. Delph stuy o Brge Coto Ratg a Effect of Improvemet, ASCE Joural of Trasportato Egeerg 117(3), p [9] Ia staar coe of practce for No-estructve testg of cocrete-metho of test (Rebou hammer) I.S (Part 1, 1992) Bureau of Ia staar (BIS). [10] Ia staar coe of practce for Metho of test of stregth of cocrete, I.S. 516 (1959) Bureau of Ia staar (BIS). IJEDR Iteratoal Joural of Egeerg Developmet a Research ( 196