Rebound, UPV & Core test.ppt

ASSESSMENT OF DAMAGES AND TESTING TECHNIQUES •

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A number of non-destructive !"rti"##$ destructive "nd destructive tec%ni&ues for "ssessment of concrete structures' To !redict t%e c"use of deterior"tion of t%e concrete in t%e e(istin) structures "re "v"i#"b#e' Interest in t%e *e#d of Non-destructive Testin) +NDT, of structures is incre"sin) or#d ide' T%ese NDT tec%ni&ues c"n be bro"d#$ c#"ssi*ed into fo##oin) four )rou!s.

ST/ENGTH TESTS 0' Sc%m Sc%midt idt H"mmer H"mmer Test Test 1' U#tr U#tr"soni "sonic c 2u#se 2u#se 3e#oc 3e#ocit$ it$ 4' 2u## out out "nd 2u## 2u## o5 Tests Tests 6' Cor Core e Test 7' 8ind 8indsor sor 2rob 2robe e +or, +or, 2ene 2enetr"ti tr"tion on /esist"nce Test 9 It is " form of %"rdness testin) :' 2u# 2u#se se Ec% Ec%o o tec% tec%ni& ni&ue ue

ST/ENGTH TESTS 0' Sc%m Sc%midt idt H"mmer H"mmer Test Test 1' U#tr U#tr"soni "sonic c 2u#se 2u#se 3e#oc 3e#ocit$ it$ 4' 2u## out out "nd 2u## 2u## o5 Tests Tests 6' Cor Core e Test 7' 8ind 8indsor sor 2rob 2robe e +or, +or, 2ene 2enetr"ti tr"tion on /esist"nce Test 9 It is " form of %"rdness testin) :' 2u# 2u#se se Ec% Ec%o o tec% tec%ni& ni&ue ue

DU/A;I"#i A))re A))re)"te )"te /e"ction 6' Abr" Abr"sion sion /esist"n /esist"nce ce Tests Tests 7' /eb"r met%od for "ssessin) t%e &u"#it$ of concrete b"sed on surf"ce %"rdness indic"ted b$ t%e rebound number' If t%e stren)t% of concrete is %i)% t%en t%e rebound number is "#so %i)%' T%e !rinci!#e of t%is test is t%"t %en t%e !#un)er of rebound %"mmer is !ressed ")"inst t%e surf"ce of t%e concrete t%e s!rin) contro##ed m"ss rebounds'

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T%e e(tent of suc% rebound de!ends u!on t%e surf"ce %"rdness of t%e concrete' T%e surf"ce %"rdness "nd t%erefore t%e rebound number is t">en to be re#"ted to com!ressive Stren)t% of t%e concrete' /ebound number v"#ues "#so de!end on t%e "n)#e of me"surement' F"ctors inuencin) "re i,

T$!e of cement A))re)"te cement content ii, T$!e of Com!"ction ")e of concrete moisture condition tem!er"ture etc'

Aer"tion T"n> 

2#"te Sett#in) T"n> 

/ebound H"mmer Test

/esu#ts of /ebound H"mmer Test N"me of t%e Structure . Aer"tion t"n>  S#' No'

/ebound Numbers

Aver")e

St"nd"rd Devi"tion

0

41

40

44

46

47

4:

44'7B

0'0

1

41

41

46

44

46

46

44'0

B'4

4

47

4:

6B

4:

4

47

4:'4

1'04

6

46

4:

4:

4:

4:

47

47'7B

B'4

7

4

6B

61

60

4:

46

4'7B

4'B1

:

4

47

4

4:

4

47

4:'7B

0'4



1

46

1

1:

1

41

1'44

4'B



4

44

41

4

46

47

47'BB

1'74B

U#tr"sonic 2u#se 3e#ocit$ Test U#tr"sonic 2u#se 3e#ocit$ +US23, met%od is bein) e(tensive#$ used to "ssess t%e &u"#it$ of concrete' T%is test is )ener"##$ used for me"surement of concrete uniformit$ determin"tion of cr"c>in) "nd %one$combin) "nd "ssessment of concrete deterior"tion' Stren)t% estim"tion &u"#it"tive#$ "ssessed' •

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T%e 2rinci!#e of US23 me"surement invo#ves sendin) e#ectro-"coustic !u#se t%rou)% " concrete !"t% "nd me"surin) t%e tr"nsit time t">en for " >non dist"nce' 2u#se ve#ocit$ is t%en com!uted' T%is !u#se ve#ocit$ de!ends m"in#$ on e#"stic modu#us of t%e concrete' An$ f"ctor %ic% inuences t%e modu#us of e#"sticit$ of concrete i## "#so "5ect its !u#se ve#ocit$'

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T%e direct met%od of testin) is t%e most re#i"b#e from t%e !oint of vie of tr"nsit time me"surement' As m"(imum !u#se ener)$ is tr"nsmitted "t ri)%t "n)#es to t%e f"ce of tr"nsmitter'

U#tr"sonic 2u#se 3e#ocit$ Test

S#ud)e Dr$in) ;eds

/esu#ts of U23 Test N"me of t%e Structure . Aer"tion T"n> 

Time (T) (Seconds) x10-6

Ultrasonic Plse !elocit" ( !#L $ T ) (km $ sec)

Sl..No.

Path Length (L) km x10-3

1

0.%

1&%

'.00

&

0.%

1&3

'.0

3

0.%

11%

'.3%

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0.%

116

'.31

%

0.%

116

'.31

6

0.%

1&1

'.13



0.%

11

'.&'



0.%

116

'.31

*

0.%

111

'.%0

/em"r>s

C"rbon"tion Test •

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Concrete is %"vin) micro-!ores "nd t%ese !ores "re *##ed it% #i&uid %"vin) !H-v"#ue "s %i)% "s 01'7' T%us concrete is "#>"#ine in n"ture' T%is "#>"#init$ of t%e concrete is due to +OH, ions in !ore "ter' 8%ic% "re !roduced b$ t%e disso#ution of C"+OH,1 from t%e so#id !%"se of t%e cement )e# into t%e !ore "ter "nd from t%e c"ustic "#>"#is !resent n"me#$ !ot"ssium "nd sodium o(ides'

Carbonation of the concrete is the reaction of Ca(OH)2 with the atmospheric CO2, and its conversion into CaC03. •

This reaction lowers the pH-vale of the pore water to abot !.3 •

The oter "one of concrete is a#ected $rst, bt de to the passa%e of time, carbonation proceeds deeper into the mass as •

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If c"rbon"tion de!t% become e&u"# to cover of concrete stee# reinforcement is t%en !rone to corrosion d"m")e' ;$ C"rbon"tion test e me"sure t%e c"rbon"ted de!t% of concrete' To determine t%e de!t% of c"rbon"tion dri##in) of " %o#e is done in st")es "nd t%e !%eno#!%t%"#ein so#ution is s!r"$ed in it "fter ever$ st")e' As soon "s t%e concrete become !in> dri##in) is sto!!ed "nd t%e de!t% of t%e %o#e me"sured'

Core Test •

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Core Test is one of t%e best met%ods to "ssess t%e stren)t% of t%e concrete in reinforced concrete construction' Com!ression testin) "nd 2etro)r"!%ic e("min"tion of cores cut from %"rdened concrete' It is " e## est"b#is%ed "nd most re#i"b#e met%od en"b#in) visu"# ins!ection of t%e interior re)ions "nd direct estim"tion of t%e stren)t%' T%e resu#ts obt"ined from t%e ot%er non-destructive tests "re )ener"##$ veri*ed usin) core test'

Core t">in) M"c%ine

C"rbon"tion Test