STUDY ON ANCHOR BEHAVIOR OF CFRP PLATE TO CONCRETE

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1 Octor -7, 8, Bijing, China STUDY ON ANCHOR BEHAVIOR OF CFRP PLATE TO CONCRETE Kntaro MATSUNAGA and Tsutomu YANO and Hiroyuki NAKAMURA and Nouhiro HISABE and Toshiyuki KANAKUBO Graduat Studnt, Graduat School o Sys. and Ino. Eng., Univrsity o Tsukua, Iaraki, Japan ABSTRACT : Constc Enginring Corporation, Tokyo, Japan Mitsuishi Plastics, Inc., Tokyo, Japan Associat Prossor, Univrsity o Tsukua, Iaraki, Japan, Dr.E. matsunaga@rcs.kz.tsukua.ac.jp, t-yano@constc.co.jp, h-nakamura@constc.co.jp, hisa.nouhiro@m.mpi.co.jp, kanakuo@kz.tsukua.ac.jp In this study, dirct shar typ ond tst is conductd to xamin th anchor havior o CFRP plat to concrt. CFRP plat is ondd to concrt and anchord y iv typs o anchor mthod. In cas o anchorag mthod y caron ir sht, th donding o CFRP plat is rstraind atr maximum load. In cas o anchorag mthod y multilayr CFRP plat, ctivnss o anchor strngth is not conirmd. In cas o anchorag mthod y stl plat, most ctiv anchor havior is otaind and maximum load is mor than.5 tims o th calculatd ond strngth without anchorag. In cas o anchorag mthod y mortar spacr and caron ir sht, maximum load is.9-.7 tims o th calculatd ond strngth. Evn i load dcrass onc, load incrass again to aout.-.9 tims o th maximum load. In cas o anchorag mthod y sid CFRP plat and caron ir sht, ond strngth incrass y sharing th tnsil orc through caron ir sht. KEYWORDS: CFRP plat, Bond, Anchor, Slippag, Caron ir sht. INTRODUCTION In rcnt yars, continuous ir sht hav n usd as rinorcing matrial or concrt structur. Manwhil, CFRP (Caron Fir Rinorcd Plastic) plat with its gratr stinss than continuous ir sht has an advantag o workaility. Thror, CFRP plat has n usd or lxural strngthning on am or sla. It is th most important to transmit th orc twn CFRP plat and concrt. Th ond strngth twn CFRP plat and concrt has n invstigatd in th prvious rsarch []. Howvr, CFRP plat should ndd to anchor i dsign orc o CFRP plat xcds ond strngth twn CFRP plat and concrt. In this rsarch, in ordr to incras ond strngth y anchorag, iv typs o anchoring mthods or CFRP plat ar xamind. Thos ar anchoring y ovrlap o ir sht, multilayr CFRP plat, stl plat and anchor olts, mortar spacr and caron ir sht and sid CFRP plat and caron ir sht. In this study, th spcimns o concrt lock on which CFRP plat is attachd with poxy rsin, is loadd to conirm th ct o iv typs o th anchoring mthod and th local anchorag havior o th CFRP plat is invstigatd.. OUTLINE OF LOADING TEST.. Spcimn Figur shows th shap o spcimn. Th spcimn is th concrt lock and rinorcing ar ar st in it. CFRP plat with 5mm in width is attachd on concrt lock with putty typ (high viscosity) poxy rsin. Thn, ach typ o th anchoring mthod is applid.

2 Octor -7, 8, Bijing, China Figur Th shap o spcimn Typ A anchorag mthod is that caron ir sht with mm in width is attachd on r nd o CFRP plat. Thir ir dirction is prpndicular to CFRP plat. Th sht is attachd on latral sid o concrt lock y mm or mm, calld anchorag lngth. In cas that anchorag lngth is mm, th sht is thr layrd. In cas that anchorag lngth is mm, th sht layr is. In Typ B anchorag mthod, multilayr CFRP plat, which lngth is mm and sam typ and thicknss o as CFRP plat, is attachd ovr th as plat at th r nd. Thir ir dirction is sam. Typ C anchorag mthod is using stl plat and anchor olts. Th thicknss o stl plat is 9mm. Th anchor olt is insrtd to concrt y tims o its diamtr. Typ D anchorag mthod is that caron ir sht with mm in width is attachd on r nd o CFRP plat atr mortar spacr which shap is rctangular is ixd on sam position y poxy rsin. Anchorag lngth o ir sht is mm. Th on-way typ ir sht or two-way typ ir sht is applid. Typ E anchorag mthod is that additional CFRP plats, which lngths ar mm, ar attachd at th oth sids o as CFRP plat. Morovr, two-way typ caron ir sht which shap is symmtric hxagon is attachd on thm. Th layr numrs o caron ir sht is, or and th lngth rom th up-nd position o sid plat is 5mm or mm. Th typ and thicknss o sid plat is sam as as plat. Th total spcimn numr is 5... Usd Matrial Normal concrt o thr lvls o comprssiv strngth,.5, and MPa ar usd. Tal shows th rsults o comprssion tst o tst pic. Elastic modulus is a scant modulus. Tal shows mchanical proprtis o CFRP plat. Th two typs CFRP plat, high strngth typ and high stinss typ, ar tstd. Th width o CFRP plat is 5mm. Th stinss o CFRP plat is dind as thicknss tims lastic modulus o CFRP plat. Tal shows mchanical proprtis o caron ir sht. Th unit wight o ir sht is gm. Th width o caron ir sht is mm. For typ A anchorag mthod, thr layrd caron ir sht is attachd in cas o mm anchorag lngth, and on layrd sht is attachd in cas o mm anchorag lngth. Stl plat has th rctangular shap with mm in width, mm in lngth and 9mm in thicknss. Stl plat has or hols or anchor olt which diamtr is mm or mm. Th numr o anchor olt is or. Mortar spacr is th shap o rctangular solid with 5mm in width, mm in lngth and or 8 or mm in thicknss. Th rsult o comprssion tst o tst pic o mortar shows that comprssiv strngth is 5.9MPa and lastic modulus is 5.GPa.

3 Octor -7, 8, Bijing, China Tal Mchanical proprtis o concrt Th typ A or B or C o anchorag mthod Th typ D or E o anchorag mthod Concrt typ Comprssiv strngth Elastic modulus Comprssiv strngth Elastic modulus (GPa) (GPa) Tal Mchanical proprtis o CFRP plat Typ Nam Tnsil strngth Elastic modulus Thicknss Stinss (GPa) (knmm) High strngth G G 5 5. High stinss H 8. 9 Tal Mchanical proprtis o caron ir sht Fir Thicknss Tnsil strngth Standard lastic modulus Elastic modulus Anchorag Typ dirction (GPa) (GPa) mthod 5 A High strngth.7 8 D Middl lastic A High strngth.8 9 A, D, E.. Mthods o ing and Masurmnt Dirct shar typ ond tst is conductd y pullout th uppr ara o CFRP plat., horizontal and vrtical displacmnts and strains o caron ir sht ar xamind. Th horizontal displacmnt is masurd at th position o 5mm rom th r nd o CFRP plat and vrtical on is masurd at mm rom it. Uni-axial strain gaugs ar usd in th cas o th on-way typ ir sht and tri-axial strain gaugs ar usd in th cas o two-way typ ir sht.. BOND STRENGTH CALCULATION In ordr to compar maximum load otaind y loading tst with ond strngth in cas that CFRP plat is attachd to concrt only y poxy rsin, ond strngth is calculatd as ond lngth in mm y prviously rportd mthod []. Th ond strngth calculation ormulas ar shown low. l τ k τ P = k τ., max. 5 σ B = (.) t p E p s = (.) k τ,max,max p p,max l l ( l ( l > l ) < l ) (.) k l + k k = cos + π l (.) Whr, maximum local ond strss τ,max, concrt comprssiv strngth σ B, ctiv ond lngth l, width p and thicknss t p and lastic modulus E p o CFRP plat, local slippag o th ctiv ond ara s (.mm), strss coicint o EBSB (Equivalnt Bond Strss Block) in cas o ctiv ond lngth k (.8), ond lngth l, ond strngth P, strss coicint o EBSB k. Ectiv ond lngth is dind as th rgion that ond strss coms mor than % o th maximum ond strss. Tal shows calculatd ond strngth.

4 Octor -7, 8, Bijing, China Concrt typ.5 CFRP plat Tal Calculatd ond strngth Th typ A or B or C anchorag mthod Ectiv Bond strngth ond lngth Th typ D or E anchorag mthod Ectiv Bond strngth ond lngth G G H G G H G G H RESULTS OF EXPERIMENT.. Typ A Anchorag Mthod Tal 5 shows rsults o xprimnt. Th maximum load tnds to incras with incras o concrt strngth or th stinss o CFRP plat. It is considrd that th lastic modulus o caron ir sht dos not act th maximum load. Whn th high strngth typ CFRP plat is anchord y th typ A anchorag mthod, th maximum load o two-way typ ir sht is largr than that o on-way typ. In othr hand, in cas o th high stinss typ CFRP plat, sam trnd is not osrvd. Almost sam maximum load or anchorag lngth mm is otaind with anchorag lngth mm. Th ratio o maximum load to calculatd ond strngth rangs rom.9 to.5. In almost all spcimns, th maximum load xcds calculatd ond strngth and ond strngth can improvd y anchorag. Spcimn Nam o spcimn* Tal 5 Tst rsults (Typ A anchorag mthod) At maximum load At maximum ond strss Bond strss Slippag displacmnt Maximum load Calculatd ond strngth A-G A-H A-G A-G A-G A-G A-G A-G A-G A-H A-H A-H A-H A-H A-G A-H * Anchorag mthod, concrt strngth-cfrp plat-lastic modulus o caron ir sht-anchorag lngth-ir sht typ Figur shows th ond strss vrsus slippag rlationship. Bond strss dcrmnt atr th maximum ond strss inishs at slippag around mm and thn ond strss incrass slightly with incras o th slippag.

5 Octor -7, 8, Bijing, China Bond strss Bond strss Slippag Slippag Figur Bond strss vrsus slippag rlationship Typ B Anchorag Mthod Tal shows th rsults o xprimnt. Th maximum load incrass with incras o th thicknss o CFRP plat and th numr o multilayr CFRP plat. Howvr, it dcrass with incras o th lastic modulus o CFRP plat. Th ratio o maximum load to calculatd ond strngth rangs rom.7 to.9. Thr is no improvmnt y this typ o anchorag mthod or local ond strngth. Spcimn Nam o spcimn* Tal Tst rsults (Typ B anchorag mthod) At maximum load At maximum ond strss Bond strss Slippag displacmnt Maximum load Calculatd ond strngth 7 B-G-G B-G-G B-G-G B-H-H * Anchorag mthod, concrt strngth-cfrp plat-multilayr CFRP plat-numr o multilayr CFRP plat Figur shows th ond strss vrsus slippag rlationship. Th slippag at maximum ond strss tnds to dcras with incras o th stinss o CFRP plat. Th slippag around maximum ond strss suddnly incrass. Bond strss Slippag Figur Bond strss vrsus slippag rlationship

6 Octor -7, 8, Bijing, China.. Typ C Anchorag Mthod Tal 7 shows th rsults o xprimnt. Th maximum load tnds to incras with incras o concrt comprssiv strngth, th stinss o CFRP plat and incras o th total sctional ara o th anchor olts in gnrally. Th ratio o maximum load to calculatd ond strngth rangs rom.5 to 5.. Bond strngth can largly improvd up y stl plat and anchor olt anchorag mthod. Spcimn Nam o spcimn* Tal 7 Tst rsults (Typ C anchorag mthod) At maximum load At maximum ond strss Bond strss Slippag displacmnt Maximum load Calculatd ond strngth C-H-M C-H-M C-G-M C-G-M C-G-M C-G-M C-G-M C-H-M C-H-M C-H-M C-H-M * Anchorag mthod, concrt strngth-cfrp plat-th diamtr o anchor olt-th numr o anchor olt.. Typ D Anchorag Mthod Tal 8 shows th rsults o xprimnt. Th maximum load incrass in almost linar to concrt strngth in th cas o G. Howvr, th sam tndncy is not osrvd in th cas o H. Th maximum load incrass with incras o th stinss o CFRP plat in th cas o D and D spcimns. Th maximum loads ar almost sam twn and 8mm o th thicknss o mortar spacr, whil it incrass in th cas o mm. Th maximum load with two-way typ ir sht is largr than that o on-way ir. Th ratio o maximum load to calculatd ond strngth rangs rom.9 to.7. In all spcimns, th maximum load xcds th calculatd ond strngth and ond strngth incrass y mortar spacr and caron ir sht anchorag. Spcimn Nam o spcimn* Tal 8 Tst rsults (Typ D anchorag mthod) At maximum load At maximum ond strss displacmnt Coninmnt orc Bond strss Slippag Maximum load Calculatd ond strngth D-G D-H D-G D-G D-G D-H D-H D-H D-G D-H * Anchorag mthod, concrt strngth-cfrp plat-thicknss o mortar spacr-ir sht typ Figur shows th ond strss vrsus slippag rlationship. Atr th ond strss rachd th maximum, th ond strss dcrass aout hal o th maximum on at slippag o.5mm and thn th ond strss incrass again to aout -9% o th maximum. Th spcimn o two-way ir sht shows ruptur o ir sht or larg slippag.

7 Octor -7, 8, Bijing, China 9 9 Bond strss 8 Bond strss Slippag 5 5 Slippag Figur Bond strss vrsus slippag rlationship Th tnsil orc o ir sht T is calculatd y th strain ε otaind y strain gaugs using Eq. (.). T = E ε t (.) E is th lastic modulus o th caron ir sht, t is th thicknss and is th width. Th prpndicular componnt T sinθ is th coninmnt orc or CFRP plat. Figur 5 shows coninmnt orc vrsus slippag rlationship. Tal 8 also shows th coninmnt orc at maximum load. Th coninmnt orc at maximum load is aout kn, which would contriut to th incras o th ond strngth. Howvr, th maximum load dos not tnd to incras with th incrmnt o coninmnt orc at th maximum. Coninmnt orc.87 kn.7 kn At th maximum Maximum 5 5 Slippag Figur 5 Coninmnt orc vrsus slippag rlationship.5. Typ E Anchorag Mthod Tal 9 shows th rsults o xprimnt. Th maximum load incrass with incras o th thicknss o CFRP plat and th numr and attachd lngth o th caron ir sht. Th ratio o maximum load to calculatd ond strngth rangs rom.5 to.8. In all spcimns, th maximum load xcds th calculatd ond strngth. Th ond strngth can incras y th incrmnt o ondd ar o CFRP plat and orc transmission through ir sht. Figur shows th ond strss vrsus slippag rlationship. Th slippag around maximum ond strss suddnly incrass. For th spcimn 8, atr maximum ond strss, ond strss dcrass slowly whil slippag incrass to mor than mm.

8 Octor -7, 8, Bijing, China Spcimn Nam o spcimn* Tal 9 Tst rsults (Typ E anchorag mthod) At maximum load At maximum ond strss Shar rat o th orc Bond strss Slippag Lt Cntr displacmnt (%) (%) Right (%) Maximum load Calculatd ond strngth E-G E-G E-G E-G E-G E-G E-H E-H E-H E-H * Anchorag mthod, concrt strngth-cfrp plat-numr o sht layr-attachd lngth Bond strss Slippag Slippag Figur Bond strss vrsus slippag rlationship Bond strss 8 8 Th load, which is carrid y sid CFRP plats through caron ir sht rom as CFRP plat at maximum load, is otaind y th vrtical strain o caron ir sht. Th shar rat is dind as th ratio o carrid orc y sid plat to whol tnsil load. Th rsult o calculation is shown in Tal 9. Th orc rom 7 to 9% is carrid on th as CFRP plat. 5. CONCLUSIONS. In cas o anchorag mthod y caron ir sht, th donding o CFRP plat is rstraind atr maximum load.. In cas o anchorag mthod y stl plat, most ctiv anchor havior is otaind and maximum load is mor than.5 tims o th calculatd ond strngth.. In cas o anchorag mthod y mortar spacr and caron ir sht, maximum load is.9-.7 tims o th calculatd ond strngth. Evn i load dcrass onc, load incrass again to aout.-.9 tims o th maximum load.. In cas o anchorag mthod y sid CFRP plat and caron ir sht, ond strngth incrass y sharing th tnsil orc through caron ir sht. REFERENCES. Yano, T., Izawa, K., Trashima, Y., Nakao, S., Kanakuo, T., Matsunaga, K., Hisa, N., Ishikawa, T. (7). Study on ond havior twn CFRP plat and concrt. Summaris o Tchnical Paprs Annual Mting Architctural Institut o Japan Structur IV, -.

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