Strengthening of Deteriorating Decks of Highway Bridges in Indiana Using FRPC

Transcription

1 Final Reprt FHWA/IN/JTRP-2001/15 Strengthening f Deterirating Decks f Highway Bridges in Indiana Using FRPC by Elisa D. Stelin Assciate Prfessr Schl f Civil Engineering Purdue University Ming-Hung Teng Research Assistant Schl f Civil Engineering Purdue University Jint Transprtatin Research Prgram Prject N. C-36-56EEE File N SPR-2490 In Cperatin with the Indiana Department f Transprtatin and the Federal Highway Administratin Purdue University West Lafayette, Indiana Nvember 2001

2 1. Reprt N. 2. Gvernment Accessin N. 3. Recipient's Catalg N. FHWA/IN/JTRP-2001/15 TECHNICAL REPORT STANDARD TITLE PAGE 4. Title and Subtitle Strengthening f Deterirating Decks f Highway Bridges in Indiana Using FRPC 5. Reprt Date Nvember Perfrming Organizatin Cde 7. Authr(s) Elisa Stelin and Ming-Hung Teng 9. Perfrming Organizatin Name and Address Jint Transprtatin Research Prgram 1284 Civil Engineering Building Purdue University West Lafayette, Indiana Spnsring Agency Name and Address Indiana Department f Transprtatin State Office Building 100 Nrth Senate Avenue Indianaplis, IN Perfrming Organizatin Reprt N. FHWA/IN/JTRP-2001/ Wrk Unit N. 11. Cntract r Grant N. SPR Type f Reprt and Perid Cvered Final Reprt 14. Spnsring Agency Cde 15. Supplementary Ntes Prepared in cperatin with the Indiana Department f Transprtatin and Federal Highway Administratin. 16. Abstract Many industries, such as the aerspace and the autmtive industries have successfully used Fiber Reinfrced Plymer Cmpsites (FRPC). These types f cmpsite materials ffer significant advantages ver cnventinal civil engineering materials, such as cncrete and steel. This is due t their chemical and crrsin resistance, lightweight, and high strength, which make them attractive fr the rehabilitatin f civil infrastructures. The bjective f this research prject is t study the feasibility f using f FRP as a retrfit r cnstructin material fr bridge decks. This has been accmplished by means f a synthesis study. This study included a cmprehensive literature review f externally bnded FRPC strengthening systems and f the current state f knwledge n technlgies invlved in the design and cnstructin f FRPC bridge decks, and a web-based survey f ther state Departments f Transprtatins (DOTs) n their use f FRPC materials fr bridge decks. 17. Key Wrds FRP, cmpsites, strengthening, bridge decks, retrfit, fiber reinfrced plymers 18. Distributin Statement N restrictins. This dcument is available t the public thrugh the Natinal Technical Infrmatin Service, Springfield, VA Security Classif. (f this reprt) 20. Security Classif. (f this page) 21. N. f Pages 22. Price Unclassified Unclassified 93 Frm DOT F (8-69)

3 INDOT Research TECHNICAL Summary Technlgy Transfer and Prject Implementatin Infrmatin TRB Subject Cde: 25-1 Bridge Design and Perfrmance Nvember 2001 Publicatin N.: FHWA/IN/JTRP-2001/15, SPR-2490 Final Reprt Strengthening f Deterirating Decks f Highway Bridges in Indiana Using FRPC Intrductin The service life f bridges is ften reduced due t the crrsin f steel reinfrcing bars in bridge decks and t the cracking caused by lading in excess t the riginal design values due t increased traffic vlumes. In Indiana, numerus bridges are in need f upgrading r rehabilitatin. Current upgrading practices include replacing the part f deterirated prtin f the deck structure by patching damaged areas r replacing the whle deck structure. Bth f these practices have drawbacks. The first is time-cnsuming and prvides nly a shrt-term slutin, while the latter is expensive and causes severe traffic disruptin. Therefre, alternative slutins shuld be devised fr the rehabilitatin and upgrading f deterirated bridge decks in Indiana. Many industries, such as the aerspace and the autmtive industries have successfully used Fiber Reinfrced Plymer Cmpsites (FRPC). These types f cmpsite materials ffer significant advantages ver cnventinal civil engineering materials, such as cncrete and steel. This is due t their chemical and crrsin resistance, lightweight, and high strength, which make them attractive fr the rehabilitatin f civil infrastructures. Strengthening f Reinfrced Cncrete (RC) structures by bnding external steel plates and cmpsite plates r sheets is an effective methd fr imprving structural perfrmance under bth service and ultimate lad cnditins. A main disadvantage f using steel plates is the ptential fr crrsin at the epxy/steel interface with cnsequent reductin in bnd strength when expsed t harsh envirnments. Cmpsite plates r sheets, n the ther hand, ffer several advantages ver their steel cunterparts, such as ease bndage t irregular surfaces, lightweight, etc. FRPC have been used in the replacement f deficient bridge decks. Studies f the feasibility and lng-term perfrmance f this type f applicatin have been cnducted. These studies have cncluded that nt nly FRPC decks shuld be cnsidered as an alternative t cnventinal reinfrced cncrete decks; they have a number f advantages ver the latter. In particular, their ease f cnstructin shuld be highlighted: instead f weeks nly a few days are required fr their successful installatin and cnsequently, traffic disruptins are minimized. The bjective f this research prject is t study the feasibility f using f FRP as a retrfit r cnstructin material fr bridge decks. This has been accmplished by means f a cmprehensive literature review f externally bnded FRPC strengthening systems and f the current state f knwledge n /01 JTRP-2001/15 INDOT Divisin f Research West Lafayette, IN 47906

4 technlgies invlved in the design and cnstructin f FRPC bridge decks. In additin, valuable infrmatin has been btained thrugh a web-based survey f ther Findings The results frm the literature review indicate that by externally bnding FRP plates (r sheets) and/r rds prvide excellent retrfitting mechanisms t increase deck strength as well as stiffness f aging r deterirated structures. The advantages f this retrfitting methd include reduced labr csts, minimum shutdwn time/cst and traffic disruptin, and minimal maintenance requirements. Frm the literature review, it was fund that the values f such the increase in stiffness and strength varied fr the different field applicatins. Hwever, in all cases such an increase was bserved. Furthermre, it was als fund that the benefits f such a retrfitting system d nt change with time. A number f demnstratin prjects that studied FRP bridge deck panels have been cnducted cuntrywide. These prjects range frm small-scale pedestrian bridges t large-scale highway bridges as well as frm deck replacement t bridges made entirely f cmpsite materials. Mst f the studies reprt that their FRP applicatins are perfrming very well. In fact, sme f these applicatins are nw 3 r 4 years ld and cntinue t shw excellent perfrmance. In all cases, it is reprted that the installatin time is significantly reduced when cmpared t cnventinal reinfrced cncrete decks. The experience f ther state DOTs in the use f FRP as a retrfit and as a Implementatin The current state f knwledge f FRP materials as a cnstructin material fr civil infrastructure indicates that it can be successfully used in many types f applicatins. The present study fcuses in their use fr bridge decks. In rder t further benefit frm this technlgy, Indiana state Departments f Transprtatins (DOTs) n their experience with FRPC materials fr bridge decks. cnstructin material fr bridge decks was investigated by means f a web-based survey. All 50 state DOTs were cntacted and 34 respnded the survey. Of the respnding DOTs, 23 respnded that they have used FRP fr bridge desk rehabilitatin and/r installed FRP bridge decks. The majr reasns prvided by these states fr adpting FRP materials were their excellent strength, lightweight, and durability. Mst f the states using FRP as a material fr bridge deck rehabilitatin reprted that its main use was t strengthen and upgrade damaged bridge decks. Eight states respnded that they had replaced a reinfrced cncrete bridge deck by a FRP bridge deck. Based n their experience, these DOTs have nt bserved any prblems with their FRP applicatin. Twenty state DOTs have respnded that they are cnsidering using FRP in the future. Mst f them plan t utilize FRP as a strengthening/upgrading system. The results frm the literature review and DOT survey indicate that FRP materials have been successfully used in civil infrastructure applicatins, and in particular fr bridge deck strengthening and replacement. It als appears, frm the results f this study that the use f FRP in bridges is likely t cntinue and ptentially becme a mainstream material in the near future. must becme part f the increasing research effrts in this area. Therefre, it is strngly recmmended that a demnstratin prject be develped in this state. With this in mind, a prpsal has been develped and submitted t the FHWA Innvative Bridge Research and Cnstructin (IBRC) prgram /01 JTRP-2001/15 INDOT Divisin f Research West Lafayette, IN 47906

5 In the prpsed prject, the three main spans f a bridge deck in Tippecane Cunty will be replaced by 8 FRP deck panels. The scpe f this prject includes the evaluatin and design f FRP bridge deck panels t meet current cde Cntacts Fr mre infrmatin: Prf. Elisa Stelin Principal Investigatr Schl f Civil Engineering Purdue University West Lafayette IN Phne: (765) Fax: (765) requirements. It als invlves the recnstructin f an existing bridge deck using the innvative FRP deck panels. The mnitring f the perfrmance f the develped applicatin will als be part f the prpsed IBRC prject. Indiana Department f Transprtatin Divisin f Research 1205 Mntgmery Street P.O. Bx 2279 West Lafayette, IN Phne: (765) Fax: (765) Purdue University Jint Transprtatin Research Prgram Schl f Civil Engineering West Lafayette, IN Phne: (765) Fax: (765) /01 JTRP-2001/15 INDOT Divisin f Research West Lafayette, IN 47906

6 TABLE OF CONTENTS 1. Intrductin 1.1. Backgrund Objective Organizatin f the Reprt FRP as External/Internal Retrfits fr Bridge Decks 2.1. Intrductin Literature Review Manufacturers f External FRP Reinfrcement Systems fr Bridge Decks FRP Bridge Decks 3.1. Intrductin Literature Review FRP Bridge Deck Manufacturers Survey f State DOTs 4.1. Intrductin Summary f State DOTs Respnses General FRP Bridge Decks FRP Retrfits fr Bridge Decks... 59

7 5. Summary f Findings, Cnclusins, and Recmmendatins 5.1. Summary FRP Retrfits fr Bridge Decks Summary FRP Bridge Decks Summary Summary f Survey f State DOTs Cnclusins Recmmendatins List f References Appendix A: Shrt Survey Appendix B: Detailed Survey Appendix C: IBRC prpsal.. 90

8 CHAPTER 1. Intrductin 1.1 Backgrund The service life f bridges is ften reduced due t the crrsin f steel reinfrcing bars in bridge decks and t the cracking caused by lading in excess t the riginal design values due t increased traffic vlumes. In Indiana, numerus bridges are in need f upgrading r rehabilitatin. Current upgrading practices include replacing the part f deterirated prtin f the deck structure by patching damaged areas r replacing the whle deck structure. Bth f these practices have drawbacks. The first is time-cnsuming and prvides nly a shrt-term slutin, while the latter is expensive and causes severe traffic disruptin. Therefre, alternative slutins shuld be devised fr the rehabilitatin and upgrading f deterirated bridge decks in Indiana. Many industries, such as the aerspace and the autmtive industries have successfully used Fiber Reinfrced Plymer Cmpsites (FRPC). These types f cmpsite materials ffer significant advantages ver cnventinal civil engineering materials, such as cncrete and steel. This is due t their chemical and crrsin resistance, lightweight, and high strength, which make them attractive fr the rehabilitatin f civil infrastructures. Strengthening f Reinfrced Cncrete (RC) structures by bnding external steel plates and cmpsite plates r sheets is an effective methd fr imprving structural perfrmance under bth service and ultimate lad cnditins. A main disadvantage f using steel plates is the ptential fr crrsin at the epxy/steel interface with cnsequent reductin in bnd strength when expsed t harsh envirnments. Other disadvantages are transprtatin, strage, installatin difficulties as well as increase t the structure self-weight. Cmpsite plates r 1

9 sheets, n the ther hand, ffer several advantages ver their steel cunterparts, such as ease bndage t irregular surfaces, lightweight, etc. Figure 1.1 shws a cmparative sketch f the prcedures usually required fr the installatin f these tw types f retrfits. Anther exciting applicatin invlves the use f FRPC in the replacement f deficient bridge decks. Sme investigative studies have been cnducted t date t study the feasibility and lngterm perfrmance f this type f applicatin. These studies have cncluded that nt nly FRPC decks shuld be cnsidered as an alternative t cnventinal reinfrced cncrete decks; they have a number f advantages ver the latter. In particular, their ease f cnstructin shuld be highlighted: instead f weeks nly a few days are required fr their successful installatin and cnsequently, traffic disruptins are minimized. While it may be t sn t tell, it is expected that FRP applicatins will have a much lnger life span than applicatins that use traditinal civil engineering materials, since FRP is crrsin resistant. Hwever, mre research is needed t determine the lng-term behavir f these materials under varius envirnmental and lading cnditins. While cmpsite materials have been widely used in ther industries, their applicatin t Civil Infrastructures is relatively new. Hwever, bth researchers and practicing engineering have recgnized that these materials will eventually becme part f the civil industry mainstream. FRP plates r sheets prvide an effective slutin fr strengthening bridge decks that have becme deficient due t deteriratin, additinal service lads r excessive deflectins created by change in use, cnstructin r design defects, r cde changes. Furthermre, FRP deck panels are a prmising alternative as a replacement f cnventinal reinfrced cncrete bridge decks. This reprt fcuses n these tw applicatins f FRP t bridge decks. 2

10 1.2 Objective The bjective f this research prject is t study the feasibility f using f FRP as a retrfit r cnstructin material fr bridge decks. This has been accmplished by means f a cmprehensive literature review f externally bnded FRPC strengthening systems and f the current state f knwledge n technlgies invlved in the design and cnstructin f FRPC bridge decks. In additin, valuable infrmatin has been btained thrugh a survey f ther state Departments f Transprtatins (DOTs) n their use f FRPC materials. 1.3 Organizatin f the Reprt The rganizatin f this reprt is prvided next. In Chapter 2, a literature review n the usage f FRPC strengthening systems fr bridge decks is carried ut. Chapter 3 presents the current state f knwledge f FRP bridge decks. On bth f these chapters, lists f relevant manufacturers are prvided. In Chapter 4, the results frm the survey f all state DOTs are summarized. Finally, in Chapter 5 recmmendatins are prvided t INDOT fr the implementatin f FRP decks in Indiana. In particular, the develped prpsal submitted t the FHWA Innvative Bridge Research and Cnstructin (IBRC) prgram is given in Appendix C. 3

11 Figure 1.1 Installatin f bridge deck retrfits (Emmns et al., 1998) Figure 1.2 Cmpnents f the bnding material in FRPC sheets (Emmns et al., 1998) 4

12 Chapter 2. FRP as External/Internal Retrfits fr Bridge Decks 2.1. Intrductin Advanced cmpsite materials usually have tw cmpnents: a reinfrcing element and a supprting matrix. The reinfrcing element is, in general, much stiffer and strnger than the matrix and as such, it is the lad-carrying element. The matrix, n the ther hand, prvides lateral supprt fr the reinfrcing element (Teng et al. 2000). The matrix in Fiber Reinfrced Plymer Cmpsites (FRPC) cnsists f a plymer/resin used as a binder material. It supprts and separates the fibers, and it prtects the fibers against severe envirnmental cnditins. Thermsetting plymer resins are the mst cmmn types f matrix element. In particular, plyesters, epxies and phenlics are the mst frequently used resins in civil engineering applicatins. The FRPC reinfrcing elements are used t prvide the stiffness and strength t cmpsite materials. These reinfrcing element materials, which are typically used in civil engineering applicatins, are usually made f carbn (graphite), glass, and aramid (Kevlar ) fibers. They are imbedded in a resin matrix (e.g. epxy resins) and they prvide mst f the tensile strength f the cmpsite just as steel des in reinfrced cncrete. FRPC is usually manufactured in a cntinuusly wven frm with different lengths r directins in rder t prvide the best perfrmance fr different applicatins. Using externally bnded FRPC plates r rds t retrfit structures has been shwn t be a practical methd fr strengthening aging r deterirated structures. The advantages f this methd include reduced labr csts, minimum shutdwn time/cst and traffic disruptin, and minimal maintenance requirements. This chapter fcuses n the applicatin f this technlgy t 5

13 bridge decks. Sectin 2.2 prvides a literature review f the published research in which FRP has been used as a retrfit fr deficient reinfrced cncrete bridge decks. In Sectin 2.3, the different manufacturers f these types f FRP retrfits are prvided Literature Review Nanni (1995) In this wrk, several applicatins f externally bnded FRP reinfrcement f cncrete structures develped in Japan are discussed. Accrding t the authr, the functin f these retrfits depends n the type f applicatin, i.e., it may be any cmbinatin f strengthening, stiffening, crack arrest, r crrsin prtectin. In particular, tw examples f bridge deck retrfitting are highlighted. They are the Hata and Hiyshikura bridges. The Hata Bridge (Figure 2.1) is lcated in Kyushu Highway in Suthern Japan. In this applicatin, FRP sheets were installed n the sffit f the cantilevered wing slab t prvide the needed additinal capacity caused by the installatin f a larger windbreak wall. This prject tk was cnducted in the spring f Figure 2.1. Hata Bridge Japan (Nanni, 1995) 6

14 Tw layers f carbn FRP (CFRP) were applied bth parallel and perpendicular t the traffic directin. In sme critical lcatins three plies were used. The sheets were applied by rller brushing the adhesive t the underside fllwed by the applicatin f the FRP sheet, as shwn in Figure 2.2. The fiber were always riented in the directin parallel t the lng dimensin f the sheets, which were 50 cm wide and the length was cut t size. On-site lading test were cnducted t test the effectiveness f the strengthening methd. Mre specifically, these tests shwed the strains were reduced cnsiderably n the steel reinfrcement. Figure 2.2. Installatin f FRP sheets n the sffit f the cantilevered slab f Hata Bridge (Nanni, 1995) In the spring f 1994, the deck f the Hiyshikura Bridge lcated n the Tkand Highway was in need f upgrading due t the increased traffic lad and the presence f mapping cracks. The bridge cnsisted f a reinfrced cncrete deck supprted by steel girders. Instead f replacing the deck, the cracks were sealed and FRP wraps were applied t the underside f the 7

15 deck fr strengthening. Mre specifically, the area f sffit f the deck (164 m 2 r 1760 ft 2 ) was cvered with tw layers f CFRP placed parallel and perpendicular t the traffic directin (Figure 2.2). In rder t evaluate the develped applicatin, strain gages were installed n steel reinfrcing bars n the underside f the deck. Running vehicle tests were cnducted that shwed that the tensile strain in the steel reinfrcement reduced by 30 t 40%. Ha et al. (1996) In this wrk, the effect f envirnmental cnditins, in particular temperature and misture effects, n structures repaired by externally bnding carbn/epxy cmpsite sheets is investigated. Prtland cement was used t cast cncrete specimens. The prprtin f cement: sand: carse aggregate was 1:2:3 in vlume. The frmwrk was remved 24 hurs after casting. The curing time was 28 days at rm temperature. The average cylinder strength f the cncrete after 28 days was 18 MPa. Unidirectinal graphite/epxy cmpsite sheets were used. The thickness f the cmpsite plates varied frm 0.33 mm (3 layers) t 6 mm (45 layers). Befre bnding the FRP sheets t the cncrete surfaces, these surfaces were prepared by: (a) sandblasting until the aggregates were expsed; (b) washing with water and blasting it with air fr drying; and (c) cleaning with acetne. The preparatin f the surfaces f the cmpsite sheets cnsisted f sanding with sand paper and then cleaning with acetne. Bth accelerated tests and lng-term envirnmental tests were cnducted n the develped specimens. Tw types f accelerated tests were perfrmed. In ne f them, the specimens were immersed at rm temperature fr 60 days. In the ther, ht-cld cycles were applied, i.e., 8

16 samples were placed in an ven at 40 C fr ne week and then in a refrigeratr at -23 C fr anther week. The ttal prcess lasted 60 days. In additin, fur samples were left utdrs, under Mntreal weather cnditins, fr the lng-term envirnmental testing. Strength tests were cnducted n tw f these specimens after 200 days, while the remaining samples were tested after 28 mnths expsure. Three-pint bending tests using an MTS machine were carried ut t investigate the effect f externally bnding cmpsite sheets t cncrete with cmpsite sheets. The findings frm the expsure and strength tests can be summarized as fllws: 1. The use f externally bnded FRPC sheets t structural members can increase the flexural lading bearing capacity by up t 49%. 2. Increasing the thickness f the cmpsite sheet did nt seem t lead t an imprvement in strength. Instead, a decrease in strength was bserved when cmpsite sheet became t thick. The length f the cmpsite sheet had a nticeable effect n the strength, i.e., the lnger the cmpsite sheet, greater the strength. 3. The expsure t water fr 60 days at rm temperature f samples retrfitted with FRPC sheets had n significant effect n their lad bearing capacity. 4. The specimens subjected t 200-day and 28-mnth lng-term utdr expsure shwed a reduced lad bearing capacity. In bth cases, this reductin was less than 7%, even thugh samples subjected t 28-mnth expsure exhibited traces f debnding between the cncrete and cmpsite sheet. It is interesting t nte that the results btained by the accelerated tests using ht-cld cycles are quite clse t thse f lng-term expsure and in the cnservative side. The results als suggest that the effect f temperature is mre imprtant than humidity in term f the reductin f bnding strength. Humidity alne seems t nly have a hardening effect n the samples. 9

17 In cnclusin, the authrs have fund that using ht-cld cycles is an effective methd fr accelerated testing f the lng-term perfrmance f FRPC sheet retrfitted specimens. Finally, they cncluded that using externally bnded FRPC sheet can restre the lad bearing capacity f deficient specimens. Arckiasamy et al. (1996) In this study, tw slid slabs 1219 mm x 305 mm x 4420 mm (48 in. x 12 in. x 14 ft. 6 in.) and tw vided slabs 1194 mm x 203 mm x 6553 mm (47 in. x 8 in. x 21 ft. 6 in.) were studied. Bth f these slabs were pre-cracked and then ne f each type was reinfrced with externally bnded CFRP plates t evaluate the cntributin f the retrfit t the strength and stiffness f the slabs. The specimens were laded t failure after cmplete cure f the adhesives. Frm the tests, it was bserved that failure mde f the retrfitted slid slab ccurred by crushing f cncrete at midspan, while the cntrl precracked slab failed at pint f applicatin f the lad. The results shw that by retrfitting severely damaged slid slab with CFRP laminates, imprve significantly its flexural capacity (apprximately 90% f the flexural capacity f the uncracked slab). The retrfitted vided slab experienced a sudden and catastrphic failure. This suggests that prir damage t the slab may have existed leading t lcal cncrete crushing failure. The retrfitted slid and vided slabs exhibit larger deflectin than the cntrl precracked slabs at bth service and ultimate lads. Crack patterns f the retrfitted slabs were identical t thse f the cntrl slabs. 10

18 Alkhrdaji et al. (1999) In this study, a full-scale applicatin was tested t investigate the effectiveness f using FRPC t strengthen actual bridge decks. Mre specifically Bridge J-857, lcated n Rute 72 in Phelps Cunty, Missuri, was chsen fr testing and demlitin. Field-tests using CFRP sheets and rds as strengthening systems were cnducted. In additin, a test f a nn-strengthened bridge deck was als cnducted fr cmparisn. Figure 2.3 depict the strengthening schemes used in the three bridge decks. Figures 2.4 (a) and (b) shw the strengthened bridge deck with external CFRP sheets and rds, respectively. Figure 2.3 Retrfitting scheme used in the three bridge decks (Alkhrdaji et al., 1999) Examinatin f the test results indicates that bth strengthening systems were successful. The specific findings frm the field-testing data are given belw: 1. The increase in the mment capacity was 17% and 27% fr CFRP sheets and rds, respectively. 2. The strengthened decks had smaller deflectins (therefre higher stiffness) and higher lad capacity at the ultimate lading cnditins. 3. The CFRP rd system prvides slightly better benefits than thse f externally bnd CFRP sheets. Additinal advantages bserved included minimal surface preparatin, 11

19 rapid installatin time, and ability f anchring the reinfrcement int adjacent RC members. (a) (b) Figure 2.4 Strengthening schemes: (a) FRP sheets, (b) FRP rds (Alkhrdaji et al., 1999) Rizkalla and Labssière (1999) This article describes sme prjects in Canada that use FRP materials t strengthen bridge. One f such prjects cnsisted f the applicatin f CFRP t internally strengthen a bridge deck underneath the verlay. The develped applicatin is shwn in Figure 2.5. The structure is referred t as the Cuntry Hills Bulevard Bridge in Calgary, Alberta, Canada. The main reasn fr the bridge strengthening was that it was fund that its thin deck wuld verlad under full truck lading. The main cnsideratins that lead t the decisin t use such a retrfit, included the fact that they did nt wish t replace the whle deck (nndestructive alternative) and that they wished t minimize traffic disruptin. The prcedures used in the develpment f this applicatin were: 1. CFRP strips were installed at 20 inches center t center. 12

20 2. The deck surface was rugh. A layer f Sikadur 30 with sand aggregate was applied fr leveling purpses. 3. The CFRP strips were applied with epxy after ne day. 4. The excess epxy in each strip was remved thrugh rlling. 5. The surface f each strip was cleaned and sanded after ne day. 6. A bnding agent was applied n the back surface f each strip fur hurs prir t the installatin f the verlay. Figure 2.5 FRP strips applied n deck f the Cuntry Hills Bulevard Bridge (Rizkalla and Labssière, 1999) Anther prject described in this article is the strengthening f the Ste-Émélie-de-l Énergie Bridge in Québec, Canada using FRP materials. The site preparatin included a curing time f the cncrete used in the repair f fur weeks. The cmpsite strips were installed in eight days ver a perid f three weeks. The CFRP strips were 50 mm (2 in) wide. The behavir was mnitred using strain gages, thermcuples, and ptic fibers with Bragg sensrs r Fabry-Pert 13

21 sensrs. The Ministère de Transprts perfrmed lading test bth prir and after the repair. The gals f increasing the bending strength by 35% and the shear strength by 20% were achieved. Taerwe and Mathys (1999) In this article, the strengthening f damaged cncrete structures using FRP is discussed. In particular, the strengthening f the Tannberg Bridge in Austria is mentined, in which CFRP fabric strips were applied t the underside f the bridge deck as shwn in Figure 2.6. Freyssinet manufactured these sheets, which are referred t as TFC sheets. Details n the strengthening scheme and n the perfrmance f the develped scheme are nt prvided in this article. Figure 2.6 Strengthening f the Tannberg Bridge, Austria (Taerwe and Mathys, 1999) 14

22 May et al., 2000 Anther applicatin f reinfrcing bridge decks with FRPC is that f Missuri Bridge G-270. The damaged bridge is shwn n Figures 2.7. The strengthening methd used in this applicatin cnsisted f CFRP sheets externally bnded t the underside f the bridge deck. The Figures 2.8 shws the applicatin f the adhesive prir t the applicatin f the CFRP sheets and Figure 2.9 shws the installatin f the sheets themselves. The gal f this strengthening prject was t increase the flexural capacity f the bridge. Figure 2.7. Bridge G-270, Missuri (May et al., 2000) 15

23 Figure 2.8. Applicatin f the adhesive t the underside f the deck (May et al., 2000) Figure 2.9. Installatin f the CFRP sheets (May et al., 2000) Bth full-scale labratry and in-situ field tests were cnducted befre/after strengthening t evaluate the effectiveness f the develped strengthening system. Furthermre, the lng-term perfrmance f the bridge has als been mnitred. 16

24 In-situ field tests were cnducted befre and after strengthening t evaluate the effectiveness f the develped strengthening system in May These lad tests measured the deflectin due t a lad truck driving ver the bridge. Six passes were made by the truck n the Nrth and Suth sides and n the centerline. It is fund that in average, the deflectins after strengthening were 94% f the riginal deflectins. Hwever, it was bserved that in the mre severely deterirated areas the reductin was mre significant (at mst 77%). In August 1999, a secnd lad test was perfrmed n August 19, This fal f this test was t investigate the effects f time n the perfrmance f the system. Once again, it was fund that the deflectins were nt unifrm thrughut the bridge. It was cncluded frm this secnd lad-deflectin tests that the FRP sheets cntinue t carry tensile stresses. In fact, they fund that the deflectins are almst the same as thse measured in May Manufacturers f External FRP Reinfrcement Systems fr Bridge Decks A number f FRP manufacturers, which were riginally dedicated t ther industries such as the autmtive and aerspace industries, have been alternatively re-fcusing their scpe t the civil engineering industry. Amng these manufacturers, the nes that have participated in mst f the develped field applicatins are members f the Market Develpment Alliance f the FRP Cmpsites Industry (MDA). This self-funded, nn-prfit trade alliance is a cnsrtium f rganizatins with interest in FRP cmpsites. In additin t manufacturers and material suppliers, it als includes wners, cnstructrs, cnsultants and designers. The missin f MDA is t identify and market new applicatins fr FRP prducts. The manufacturer members fr FRP reinfrcing systems fr bridge decks are prvided in this sectin. 17

25 The use f FRP materials t strengthen cncrete structures can be traced t the 1950s, hwever their use as an external reinfrcement f cncrete bridge structures began in 1980s (MDA 2000). Accrding t MDA s reprt (MDA 2000), mre than 1000 bridges (cncrete slab/steel girders) in Japan have been strengthened by bnding FRP sheets t the slab. In the U.S., this technlgy has been widely used t retrfit clumns fr seismic upgrade. Of the cmpanies that specialize in the use f FRP sheets t retrfit bridge structures, the nes that have used this technlgy t upgrade bridge decks are listed belw. COMPTEK Structural Cmpsites, Inc. ( This manufacturer is based in New Yrk City, while its manufacturing facility (Natinal Cmpsites Center NCC) is lcated in Daytn, Ohi. Their prduct, referred t as the ATLAS System, has been develped t strengthen structural cmpnents (beams, clumns and slabs). Bth sheets and rds are manufactured using this system. Of their prducts, thse that have been used t reinfrce bridge decks are the Atlas Carbn Laminates (ACL) and the Atlas Carbn Rd (ACR). The ACL can be installed n the underside f the bridge fr strengthening (Figure 2.10), while the ACR can be embedded in the cncrete slab (Figure 2.11). Figure Atlas carbn laminates installed n underside f a cncrete slab 18

26 Figure FRP Rds embedded int a cncrete slab Fyfe C., LLC ( While this cmpany s headquarters is lcated in San Dieg, Califrnia, it has representatives thrughut the U.S. and the wrld. Their prduct, the Tyf Fiberwrap System uses wet layup and prefrmed cmpsites (unidirectinal r bi-directinal glass r carbn fibers) fr strengthening f structural cmpnents. It has been mstly used fr seismic retrfit f clumns, but it has als been used t strengthen beams and slabs bth in the psitive and negative mment regins. Mst f their cmpleted prjects have been n building structures, hwever, it has the ptential t be successfully used t upgrade bridge decks. Master Builders, Inc. ( This manufacturer, lcated in Cleveland, Ohi, has develped the MBrace Cmpsite Strengthening System, which is externally bnded t cncrete r masnry structures t increase their strength. MBrace uses unidirectinal aerspace grade carbn, E-glass, r aramid fiber 19

27 fabrics embedded in engineered materials that include epxy surface primers, putty fillers, and high slids resins. One f their cmpleted prjects is the upgrade f the MDOT Bridge G270 in Irn Cunty, MO (Figure 2.12) in May The MBrace system was applied t the underside f the bridge s deck t allw fr a larger lad rating. Figure MDOT Bridge G270 (Irn Cunty, MO) 20

28 Chapter 3. FRPC Bridge Decks 3.1. Intrductin Due t aging, envirnmentally induced degradatin, pr initial cnstructin, verlading, and lack f maintenance, bridge cmpnents such as decks, superstructures, and clumns may becme deficient. Nearly 40% f all highway bridges in the USA are classified as either functinally r structurally deficient, and in apprximately ne-half f these bridges this deficiency can be attributed t their decks (Hayes et al. 2000). It is estimated that a traditinal bridge deck lasts 35 years n average; hwever, in cld regins, such as the Midwest f the U.S., the life f a deck averages 10 years. This is because f the extensive use f de-icing salts during winter mnths (Karbhari et al. 1997). During the past decade, the use f fiber-reinfrced plymer cmpsites (FRPC) in civil infrastructures has begun t receive significant attentin by the civil engineering cmmunity. This is because these materials ffer significant advantages ver cnventinal materials due t their chemical and crrsin resistance, lightweight, and high strength. Hwever, much f the research carried ut in this area has fcused mainly in the use f these materials t retrfit existing deficient structural cmpnents such as clumns, beams, and slabs. Hwever, an exciting applicatin invlves the use f FRPC in the replacement f deficient bridge decks. This sectin prvides a summary f the research and manufacturing infrmatin available in this area. Sectin 3.2 prvides a literature review f the published research prjects in which FRP deck panels were develped. This literature review is rganized chrnlgically, i.e., frm lder t mre recent publicatins. In Sectin 3.3, the different manufacturers f FRP bridge deck panels are prvided. 21

29 3.2. Literature Review Jhansen et al. (1997) In the wrk by Jhansen et al. (1997), tw fiberglass reinfrced plastic (GFRP) truss bridges in the Glden Gate Natinal Recreatin Area, CA were investigated. GFRP was chsen fr durability and maintainability reasns. The riginal bridges had maintenance prblems, since they were made with cnventinal materials, such as wd (which experienced rtting), and steel and cncrete (which experienced severe crrsin). The lengths f the tw develped bridges are 35 ft and 70 ft. The regin where the bridges were installed is prne t seismic attacks and extreme wind cnditins. Therefre, these pssibilities were cnsidered in the design f the bridges. In the final design, the imprvement f the verall strength and stiffness was achieved by means f camber, X-bracing, and steel blts cnnectins (Figure 3.1). The installatin f each bridge tk apprximately 1.5 hurs. Bth bridges were airlifted and placed alng the cliffs. The ttal time taken t design, fabricate, ship and install these bridges was apprximately 60 days. The ttal cst f the prject (including design, fabricatin, and shipping) was $45,000. N testing r lng-term mnitring results are reprted in this paper. Hwever, the authrs pint ut that develped applicatins illustrate that the use f FRP is feasible fr lngspan bridges because f its unique strength/stiffness characteristics cmbined with its lightweight. This is particularly imprtant fr applicatins with difficult site cnstraints, such as thse where the develped applicatins were installed. The authrs als reprt that the tw bridges were easy t assemble and install, and that they are practically maintenance-free when 22

30 cmpared t bridges made f cnventinal civil engineering materials, such as cncrete, wd, and steel. Figure ft lng FRP pedestrian bridge (Jhansen et al. 1997) Karbhari et al. (1997) In Karbhari et al. (1997) an experimental prgram was cnducted t investigate different cnfiguratins f bridge deck panels, frm varius manufacturers. The FRP deck panels were develped using the fllwing three criteria: stiffness requirements, displacement limits, and cst. The tested specimens ranged frm subcmpnent, cmpnent, and field-size levels. Figure 3.2 shws the different tested panels. The main gal f their tests was t study the effectiveness f the varius deck panel cnfiguratins. T achieve this, quasi-static testing f a number f FRP deck specimens were cnducted. In all cases, it was fund that all the FRP deck specimens have much higher failure lads and cmparable initial stiffness than that f the reinfrced cncrete specimen. They have als fund that the bx and trapezid cnfiguratins have significantly better energy absrptin capacity. Ntably, ne f their main findings was that the FRP deck cmpnents 23

31 cntinued t carry lad even when substantial cracking and fracture had ccurred, i.e., n catastrphic failure was bserved. Figure 3.2. Tested deck panel specimens (Karbhari et al. 1997) Overall, they cncluded that FRP decks are a suitable alternative t cnventinal civil reinfrced bridge decks. Furthermre, they fund that these decks culd be fabricated using many different prcesses. Sme related tpics that were nt addressed in this wrk include: the respnse under dynamic lads, the behavir f the cnnectins between deck and girders, and deck and barrier and side rails, the effect f the different material prperties between FRP and existing substructure, and the lng-term durability. Chajes, M. et al. (1998) The paper by Chajes, M. et al. (1998) discusses the evlutin and status f three bridges made f advanced cmpsites in Delaware. In this research extensive mnitring thrugh bth initial lad testing and lng-term mnitring prgrams were develped 24

32 The three bridges were selected such that they were incrementally mre cmplex and had mre restrictive service requirements. These bridges were designed using the AASHTO LRFD Bridge Design Specificatins and factrs taking int accunt deteriratin f material prperties ver time were used (fr a life span f 75 years). Bth strength and service limit states were cnsidered, including the effects f fatigue lading. The first bridge, the Magazine Ditch Bridge, is a 22 m lng, single-span, simply supprted bridge (Figure 3.3). It was installed n a private service rad and it was cmpleted n June 23, This bridge carries a small traffic vlume, even thugh it is als traveled by heavily laded maintenance vehicles. The develped bridge is made f glass fiber reinfrced plymer (GFRP). A 45-mm wearing surface made f latex mdified cncrete was installed n the deck surface. The installatin f the bridge superstructure, including the edge girders and the GFRP cmpsite deck, was cmpleted in a ne day. Figure 3.3. The Magazine Ditch Bridge (Chajes, M. et al. 1998) 25

33 Labratry tests n sub-cmpnents and n a full-scale prtin f the deck (1.2 m lng by 6 m wide) were perfrmed at the University f Delaware. The test prgram included the applicatin f AASHTO service and strength lads, and fatigue tests f up t 2,000,000 cycles. The secnd bridge, Bridge 1-351, replaced an existing bridge in the state f Delaware (Figure 3.4). The riginal bridge was a 9 m lng by 12 m wide simply supprted slab bridge. The develped GFRP bridge is 9 m lng by 8 m wide, with an all-cmpsite deck. Figure 3.4. Bridge (Chajes, M. et al. 1998) Labratry tests cnducted at the University f Delaware have shwn that fatigue cycles (up t 2,000,000 fatigue cycles) d nt cause significant lsses in strength and stiffness t the GFRP deck. The design f this bridge wasimilar t that f an adjacent reinfrced cncrete bridge design. The third bridge, Bridge 12, is lcated in Rut 13 in Delaware (Figure 3.5). It represents a typical highway bridge, since it has multiple spans, is a heavily traveled rad, and carries large vlume f truck traffic. The scpe f this prject included the design, structural certificatin, sub cmpnent testing, fabricatin, cnstructin, and mnitring and evaluatin. 26

34 Figure 3.5. Bridge 12 (Chajes, M. et al. 1998) The University f Delaware is currently mnitring the three bridges. The three imprtant limit states cnsidered in this study were serviceability (deflectin), strength (stress and strain), and fatigue. The ultimate gal is t crrelate the measured respnses t the labratry test results. The mst imprtant parameters that are being measured in the mnitring prgram include: traffic statistics (including number f trucks and classificatins), strains (bth lngitudinal and transverse), deflectins, and daily weather cnditins (temperature and humidity). The cllected data is being used in the perfrmance evaluatin f the bridges with respect t the fllwing effects: live lad, sustained lad, envirnmental, thermal, and fatigue. Walker (1998) The paper by Walker (1998) describes a bridge installed ver the N Name Creek west f Russell, KS, which was pened t traffic in Nvember The bridge was made in three sectins, each 2.74 m (9 ft) wide by 7.01 m (23 ft) lng, which is the length f the bridge. The sectins were assembled at the bridge site. Strain gages were installed in the cre fr field 27

35 mnitring. The bridge was designed t withstand standard highway traffic lads as specified by the AASHTO standards. It was made entirely f fiberglass and resin. Tw fiberglass plates sandwiching a fiberglass hneycmb cre frm the bridge deck. A plymer cncrete wearing surface was installed n the tp surface t imprve tractin. It tk tw wrking days t install this cmpsite bridge. Figure 3.6. Plan view f cre f the deck system (Walker 1998) A plan view f the cre f the deck system used in this bridge is shwn in Figure 3.6. The advantage f this cre gemetry is that by changing the perid r amplitude f the sine wave the behavir can be easily mdified. Furthermre, the sine waves can be cnnected t a flat plate as shwn in Figure 3.7 (a), r alternatively they culd be cnnected nly t the facings as shwn in Figure 3.7 (b). 28

36 (a) (b) Figure 3.7. Different cre gemetries (Walker 1998) Lpez-Anid et al. (1998), GangaRa et al. (1999), GangaRa and Cair (1999) In these three papers, tw demnstratin prjects are discussed that invlve tw advanced cmpsite bridges installed n secndary rads in West Virginia. These bridges are the Laurel Lick Bridge (shrt-span FRP bridge) and the Wickwire Run Bridge (FRP deck n steel beams). The West Virginia Department f Transprtatin Divisin f Highways (WVDOH) bridge engineers were the lead participants in these effrts. Bth bridge decks were engineered using E-glass FRP. The cmpsite deck crss-sectinal shape and fiber architecture was designed t withstand highway bridge lads while minimizing the weight. The cre f the decks cnsists f full-depth hexagns and half-depth trapezids as shwn in Figure 3.8. The decks were built with a depth f 203 mm (8 in), since this is the typical depth f cncrete decks fr highway bridges. The authrs pint ut that the Pultruded FRPC deck mdules fabricated fr these field applicatins have sme f the advantages f the pultrusin prcess, namely: its lw labr and 29

37 perating csts, minimal prductin f material waste, and high prductin rate. Hwever, they als mentin that pultruted FRP decks may exhibit high stress cncentratin at re-entrant angles, which may lead t hrizntal shear failure. Figure 3.8. Cmpnents f the H-Deck (GangaRa and Craig 1999) The deck panels were frmed by cnnecting FRP deck mdules (20-ft lng by 16-ft width) with shear keys (12.7 mm (0.5 in) blind fasteners) t prvide the necessary interlcking mechanism. In additin, a tw-part plyurethane was used t bnd the FRP deck t the FRP beams, t increase the cmpsite actin. This adhesive was chsen because it has gd elngatin, high peel and energy absrbing prperties, fatigue resistance, envirnmental resistance, wrking time f at least 30 minutes, minimum surface preparatin, acceptance f variable bnd line thickness, mm, gd gap filling capabilities, and ease f applicatin fr field cnditins. The develped FRP cmpsite deck mdules were installed transverse t the traffic directin. The depth f the decks was kept at 8 since they were used as replacement t the cnventinal cncrete decks. The cnnectin between the FRP deck mdules and the steel girders was achieved by means f 0.5 in diameter blind fasteners and adhesive bnding. 30

38 A thin plymer cncrete verlay was applied n the FRP deck as the wearing surface. This was achieved by first sandblasting and cleaning the surface f the FRP deck fllwed by the applicatin f a urethane-based primer using a brm. The latter was dne t imprve the adhesin between the verlay and the deck. The ttal thickness f the plymer cncrete verlay was apprximately 1 cm (3/8 in). The Laurel Lick Bridge is a shrt-span bridge lcated ff cunty rute 26/6 in Lewis Cunty, WV. The riginal structure cnsisted f a f timber deck n steel stringers. At the time f replacement, this structure was in critical cnditin. 305x205x12.7 mm (12x12x0.5 in) beams are used t supprt the new FRP deck (Figure 3.9). Figure 3.9. Laurel Lick Bridge (Lpez-Anid et al. 1998) The Wickwire Run Bridge is lcated ff US Rute 119 in Taylr Cunty, WV. The bridge is 9.14 m (30-ft) lng by 6.60 m (21.7-ft) wide. Fur lngitudinal galvanized steel beams, spaced 1.83 m (6-ft) apart, supprt the mdular FRP deck (Figure 3.10). Frm the field tests, the authrs have cncluded that the perfrmance f develped decks is excellent, especially when they are used as a replacement fr cncrete decks. This is because FRPC decks are much lighter than decks built using traditinal materials (fr example: FRPC 31

39 deck weighs 98 Kg/m 2 while cncrete/steel decks weigh 540 Kg/m 2 ). They als mentin that they expect that the csts assciated with FRPC applicatins will decrease significantly as this technlgy becmes mre widely used. Figure Wickwire Run Bridge, WV (GangaRa et al. 1999) In the wrk by Lpez-Anid et al. (1998) labratry testing was perfrmed t establish the perfrmance f the develped deck mdules. Tw specimens were tested: ne t failure and the ther t fatigue. The first specimen, tested t failure, was a m (108 in) lng by m (36in) wide FRP deck specimen. A patch lad simulating a wheel lad was applied t the specimen. The lad level at failure was 577 kn (129.7 kip). The bserved failure mde was interlaminar shear in the pultruded material in the prximity f the bnded cnnectin. In particular, punching damage n the deck was nt bserved in these experiments. The secnd deck specimen, tested under fatigue lading, was subjected t 2 millin cycle lads frm 9 kn (2 kip) t 156 kn (35kip). Inspectin f the tested specimen did nt reveal any 32

40 crack prpagatin due t fatigue. After the applicatin f the cyclic lads the FRP deck was tested t failure. It was fund that the failure lad decreased nly by abut 4% when cmpared t the specimen with n lad histry. Hwever, the midspan deflectin increased by abut 10%. It was fund that develped FRP decks have a very high strength capacity than cncrete decks with nly 20% f the weight. Hwever, they are mre flexible when cmpared t cncrete decks. Thus, in general, serviceability (deflectin) requirements cntrl the design f FRP cmpsite decks. This is because excessive defrmatin can cause premature deteriratin f the wearing surface as well as it can affect the perfrmance f the fasteners. In the wrk by GangaRa et al. (1999), bth cmpnents and deck mdules were tested in the labratry. Three-pint static bending tests were cnducted n bth hexagnal and dubletrapezid cmpnent specimens with three different spans: 60, 84, and 108 inches. Bth a 20 x10 patch lad, intended t simulate a wheel lad f an AASHTO standard truck, and a strip lad using a 6-inch wide plate intended t cause the maximum bending strains, were applied t the specimens. The deck mdule testing included static and fatigue bending tests n 3-ft lng simply supprted deck mdules. Only the patch lad was used in the fatigue tests. Fr the fatigue tests, a sinusidal lad ranging frm 2 t 35 kips at a rate f 3 cycles per secnd was applied at a maximum f 2 millin cycles. Frm the static bending tests, it was fund that the flexural rigidity f an FRP cmpsite cmpnent is abut ne half f the flexural rigidity f an uncracked cncrete cmpnent, and abut 3.7 times f the flexural rigidity f a cracked cncrete cmpnent. Fr the fatigue tests tw FRP deck specimens were used. One was subjected t a prir lad histry (tw millin fatigue cycles), while the ther had n lad histry. Frm the results f the static failure tests, it was fund that bth specimens experienced abut the same maximum 33

41 deflectin and failure lad. Thus, the prir lad histry was fund t have n significant effect n the strength and stiffness f FRP deck. The authrs cnclude nce again that FRP has an excellent energy absrbing capability. The ultimate lad capacity f the tested FRP cmpsite deck specimens exceeded the AASHTO-HS25 lad by an excess f abut 100 kips. The failure mde f the duble-trapezid cmpnent was such that it failed at the junctin f web and flange at the applied lad lcatin. The failure mechanism cnsisted initially f web buckling at the applied lad lcatin and prpagated n bth sides f the lad patch. Fr the duble-trapezid cmpnent, failure ccurred at the web-flange junctin. This was attributed t the less than satisfactry fiber wet-ut and high stress cncentratin znes near the re-entrant angles f these specimens. In the wrk by GangaRa and Craig (1999), a third demnstratin bridge lcated in Russell, KA is discussed. In this applicatin, a Cellular deck system using multi-cellular panels made f E-glass and plyester resin cnnected by wide-flange H-sectins was used (Figure 3.11). This type f system was als successfully used in the cnstructin f a building in Westn, WV, in In this research, it is fund that this deck system is ecnmical. In particular, they have fund that these cellular deck systems are ideal fr pedestrian bridges. Figure Layut f the Cellular deck panel (GangaRa and Craig 1999) 34

42 Lpez-Anid et al. (1999) In the study by Lpez-Anid et al. (1999) high-temperature fatigue tests were perfrmed n an FRP-cncrete bridge deck. In this applicatin, the deck was made f FRP pultruded panels, which served as stay-in-place frmwrk as well as reinfrcement fr cncrete (Figure 3.12). Figure FRP-Cncrete deck and test set-up (Lpez-Anid et al. 1999) The pultruded panels were 457 mm (18 in) wide. They were stiffened using tw tubular cells f 76 mm (3 in) in height. E-glass fibers in a plyester-vinyl ester resin blend were used t frm the cmpsite material. Finishing f the material was achieved by means f epxy cating and sand spraying the tp surface. The ttal depth f the deck was 203 mm (8in), including the FRP panels. E-glass bi-directinal tp reinfrcement was used t imprve the bnd with cncrete. Since n specificatin is currently in place fr fatigue perfrmance evaluatin f FRP cncrete slabs, ne millin lad cycles at a cntrlled high-temperature (49 C) were used in this 35

43 wrk. Mre specifically, the FRP panel specimens were subjected t a maximum and minimum fatigue lad cycles f 92.5 kn and 8.9 kn, respectively, at a frequency f 4 Hz. The test specimen cnsisted f a tw-span cntinuusly supprted FRP-cncrete deck panel with a girder spacing f 2.74 m (108 in). The lad was applied t simulate an AASHTO HS20-44 wheel lad. The main gal f the tests was t mnitr the structural degradatin during the fatigue tests, since failure was nt expected t ccur during the applied lad cycles. This is because accumulatin f damage due t cyclic lading is usually reflected in lss f stiffness f the FRPcncrete deck material. Therefre, this wrk adpts the stiffness degradatin as the fatigue perfrmance criterin fr FRP-cncrete decks. The main findings frm the perfrmed tests are: A 13% decrease in stiffness was bserved fr an increase in temperature frm 19 C t 49 C. Fr high-temperatures, the stiffness decreased by apprximately 5 t 6 % within the first 100,000 lad cycles and remained almst unchanged after that and up t ne millin cycles. Fster et al. (2000) In the wrk by Fster et al. (2000), a 10-m-lng by 7.3-m-wide (33x24 ft) GFRP cmpsite highway bridge installed in Butler Cunty, Ohi is described. Bth the supprt beams and the deck were built using cmpsite materials. In rder t keep the cst f the applicatin dwn, the cmpsite bridge cmpnents (deck and the supprt beams) were made f E-glass fibers in an isplyester resin matrix. Glass fibers cst abut 10% less than carbn fibers (ften used in the aerspace industry) and isplyester resins cst less than structural epxy resin. This bridge, referred t as Tech 21, was pen t traffic in July Figure 3.13 shws the develped FRP cmpsite beam and Figure 3.14 (a) and (b) shws the assemblage f supprt beams. 36

44 Figure FRP supprt beam (Fster et al. 2000) In this applicatin, asphalt was used fr the wearing surface. Even thugh, the weight f the asphalt layer was larger than that f the deck, the AASHTO HS-20 lad requirement was satisfied. It shuld be nted that mst FRP bridge decks develped in the U.S. have adpted a plymer cncrete surface, since it is lighter in weight than asphalt. Hwever, the authrs justify their chice by the fact that highway crews are mre accustmed t using asphalt, especially fr resurfacing. In this wrk, it is reprted that the ttal installatin time f the FRP cmpsite bridge was six weeks. The authrs claim that the erectin f an equivalent reinfrced cncrete bridge wuld take ten weeks. In additin, the weight f the FRP bridge is 10.5 tns, while an equivalent RC bridge wuld weigh 89 tns. 37

45 (a) (b) Figure (a) Assembled FRP beams; (b) Underside view f the assembled FRP beams (Fster et al. 2000) The bridge was subjected t live lads slightly lwer than the required by AASHTO HS-20. Figure 3.15 illustrates this test, where the lading was applied by means f tw heavy-duty trucks fully laded with sand. The measurements were btained with 28 steel strain transducers 38

46 externally installed fr six different axle lcatins. The maximum lad in the test series was a static lad f 64.6 metric tns (142,600 lb), which prduced a maximum stress f 13.8 MPa (2,000 lb/in 2 ). In additin, the deflectin curve btained was cmparable t that f a cmparable steel span. Figure Live lad test f the Tech 21 bridge (Fster et al. 2000) The lng-term perfrmance f the FRP bridge is being mnitred using the twenty fiber ptic sensrs and 102 mechanical sensrs that were embedded in the bridge. The authrs f this wrk expect that the findings frm this research will be used in the develpment f the new AASHTO cmpsite bridge standards. Hayes et al. (2000) The wrk by Hayes et al. (2000) studies the feasibility f utilizing a cmpsite bridge deck as a replacement fr deterirated bridge decks r fr new cnstructin. Mre specifically, quasistatic and fatigue were perfrmed n a prttype cmpsite bridge deck sectin. In these tests, 39

47 the flexural strength and stiffness were measured under a simulated wheel lad. In additin, the fatigue behavir and residual strength were assessed after fatigue lading, and failure mdes frm fatigue and static ladings were determined. Twelve pultruded 102x102x6.35-mm-thick square tubes sandwiched between tw pultruded 9.53-mm-thick plates frmed the studied deck sectin (Figure 3.16). The dimensins f the specimen are 4.27-m in length, 1.22-m in width, and 121-mm in depth. The material f the plates and tubes was frmed by unidirectinal and cntinuus strand mat glass fibers in an isphthalic plyester resin. The tubes were cnnected using studs and nuts, and epxy adhesive, while the tp plates were fastened using epxy adhesive. The prttype deck panel did nt include a wearing surface, since it was assumed that such a surface wuld nt significantly affect its structural respnse. Steel girders (W16x40) parallel t the shrt side f the deck were used t supprt the deck (Figure 3.19 (a). The adpted girder spacing was 1.22-m, and the rientatin f the square tubes was transversal t the steel girders. The cnnectin between the deck and the girders was achieved with steel blts, which passed thrugh hles drilled thrugh the deck and tp flanges f the steel beams. Flat steel washers were used t prevent the blt head frm bearing directly n the tp cmpsite plate. A bearing pad was placed between the tp flange f each W16x40 and the deck. In rder t prvide transverse integrity under bearing lad, wd blck inserts were place inside the fiberglass tubes at the hle lcatins. 40

48 (a) (b) Figure The studied FRP deck: (a) Side view; (b) End view (Hayes et al. 2000) The prttype deck panel was subjected t three types f tests. The first ne was a static service lad test in the middle span f the deck; the secnd was a static lading t failure n the left end; and the third was a fatigue perfrmance and residual strength test (fatigue up t 3,000,000 cycles, fllwed by static lading t failure n the right end f the deck). A 508x305- mm lading patch was used t simulate a wheel lad n the tp surface f the deck. Figure 3.17 shws the failure mdes f the deck panel: (a) shear failure f tubes arund lad patch, (b) shear failure f the fiber blt, and (c) tp surface cracking f the deck panel. 41

49 Failure f the deck ccurred at 369 kn fr deck in as-received cnditin and 369 kn fr decks subjected previusly t fatigue strength test. These lads are abut fur times the design wheel lad, which is 92.6 kn. Therefre, the authrs cnclude that strength shuld nt cntrl design. The midspan deflectins f the deck panel under design wheel lad were 3.81, 3.81, and 4.32 mm fr the service lad test, the as received test, and the pst-fatigue strength test, respectively. It was fund that even thugh the prpsed deck system used ff-the-shelf pultruded sectins, it met the necessary strength perfrmance criteria. Hwever, the deflectins were fund t cntrl the design when using the AASHTO criterin fr limits f live lad deflectin fr steel, aluminum, and cncrete cnstructin. This criterin was used because n criterin is available fr FRP cmpsite cnstructin. At the ultimate failure mde, shear failure f the tp and bttm deck flanges were bserved. Even after 3,000,000 cycles f a fatigue lad in excess f the design wheel lad, n change in stiffness r strength f the deck was bserved. Finally, it was fund that the cnnectins between deck and girder did nt negatively impact the perfrmance f the deck under static r fatigue lading. 42

50 (a) (b) (c) Figure (a) Shear failure f tubes arund lad patch, (b) Shear failure f the fiber blt, and (c) Tp surface cracking f the deck panel (Hayes et al. 2000) 43

51 Ohi DOT (2000) The Ohi Department f Transprtatin spearheaded a study t evaluate different types f FRP deck panels t replace a deterirated reinfrced cncrete deck f a five-span cntinuus haunched steel plate girder bridge. This demnstratin prject is knwn as the Salem Avenue Bridge. This bridge carries six lanes f traffic and cnsists f twin structures with a lngitudinal jint and a 4-ft raised cncrete median at the center. The girder spacing is apprximately 8 feet 9 inches. The deck f the nrth bridge structure was replaced by fur different types f FRP deck systems manufactured by the fllwing fur manufacturers: Creative Pultrusins (CP), Cmpsite Deck Slutins (CDS), Hardcre Cmpsites (HC), and Infrastructure Cmpsites Internatinal (ICI) in cllabratin with Kansas Structural Cmpsites (KSCI). The CDS system (Figure 3.18(a)) is the mst similar t cnventinal reinfrced cncrete decks. This system uses FRP stay-in-place frms t supprt the cncrete deck and serve as bttm reinfrcement, and GFRP bars fr the tp reinfrcement. The CP deck system is frmed by bnding interlcking pultruded FRP tubes that are installed in the directin perpendicular t the girders (Figure 3.18(b)). The HC and the ICI deck systems are similar. Bth f these panels cnsist f a lightweight FRP cre sandwiched by high strength FRP skins. In the HP system, the cre cnsists f fam blcks wrapped with fiber clth (Figure 3.18(c)). The ICI panel s cre is made f crrugated glass fiber reinfrced sheets (Figure 3.18(d)). On all three FRP deck panels (CP, HC, and ICI) a 3/8-inch-thick plymer wearing surface manufactured and installed by Ply-Carb, Inc., was applied. Prir t the applicatin f this wearing surface, the decks surfaces were lightly sandblasted. 44

52 (a) (b) (c) (d) Figure Different types f FRP bridge decks (a) Cmpsite Deck Slutins, (b) Creative Putrusins, (c) Hardcre Cmpsites, and (d) Infrastructure Cmpsites Internatinal 45

53 This demnstratin applicatin was evaluated by a third party evaluatin team. This team was charged with the identificatin f ptential maintenance and serviceability prblems in the applicatin. A number f ptential prblems were identified by the team: In bth the HC and ICI deck panels, bth delaminatin and debnding in panel skins were detected visually and via nndestructive testing. The evaluatin team recmmended that this issue be addressed by the manufacturers. Sme f the CP, HP and ICI deck panels lift ff the haunch as much as 1/16 in. Therefre, the cnnectins between girder and deck may be inapprpriate. This prblem was nt anticipated and therefre nt used as a criterin by ODOT r the manufacturers. The evaluatin team recmmended that manufacturers tgether with ODOT t devise unifrm bearing. The wearing surface cracked abve the field jints f the CP, HP and ICI deck panels, which indicates that these jints are nt wrking prperly. This indicates that the Ply-Carb s wearing surface was nt flexible enugh t allw fr this mvement. During the evaluatin team s investigatin, the cracks were repaired with FRP fabric reinfrcement, which seem t have slved the prblem. Hairline cracking was bserved n the surface f the CDS deck. The cver was 1/2 t 3/4 inch less than the recmmended 2 inches. The cncrete deck was sealed with highmlecular-weight methcrylate (HMWM). Hwever, the team recmmended that future designs cnsider the elastic mdulus f the GFRP bars in the determinatin f the amunt f shrinkage. Jint between different deck systems did nt wrk prperly. This was caused because the different decks had different stiffness. The displacement differentials measured ranged frm 46

54 1/64 t 1/8 inch. The evaluatin team recmmended that diaphragms be develped t prvide supprt fr these jints. Water intrusin was detected in the HCI panel and water retentin was bserved in the ICI panel. Ptential water entry pints include: anchr hles, which were pen fr mre than a mnth, face plate remval frm CPI panels, r hles drilled fr screw attachment f cnduits within cncrete sidewalk. Drilling f drain hles in the underside f the panels were recmmended by the evaluatin team. While a fire ccurred alngside the HCI deck panel, n bvius structural damage seems t have ccurred. The evaluatin team recmmended peridic inspectin and mnitring FRP Deck Manufacturers A number f cmpsite deck panel manufacturers, which were riginally dedicated t ther industries such as the autmtive and aerspace industries, have been alternatively refcusing their scpe t the civil engineering industry. As mentined in Chapter 2, the manufacturers that have participated in mst f the develped field applicatins are members f the Market Develpment Alliance f the FRP Cmpsites Industry (MDA). Each FRP deck manufacturer has a demnstrated system that is applicable t a target applicatin. The manufacturer members f MDA f FRP deck panels are prvided in this Sectin. 3TEX, Inc ( This manufacturer is lcated in Cary, Nrth Carlina. While 3TEX has been invlved in areas f applicatin such as the autmtive, defense, recreatinal, etc., it has recently begun t manufacture lw-prfile cmpsite bridge decks and pedestrian bridges (girder spacing ranging 47

55 frm 2 t 3 ft). Their system, referred t as TYCOR, is cmpsed by a fam cre reinfrced in the Z-directin sandwiched by fiberglass fabric skins (Figure 3.19). This system is intended as a cmpetitr t cnventinal crrugated steel decks. This manufacturer has cmpleted ne applicatin in Mntgmery Cunty, Ohi, and is currently develping a secnd applicatin WPAFB, Ohi. Figure TYCOR bridge deck panels Creative Pultrusins, Inc. ( r This manufacturer perates in tw lcatins: Alum Bank, Pennsylvania and Rswell, New Mexic. Their prducts are manufactured using the pultrusin prcess. Their bridge deck panel, referred t as Superdeck, is frmed the pultrusin and bnding f a duble trapezid and a hexagnal sectin t frm a bridge deck mdule (Figure 3.20). This deck is 20% lighter than reinfrced cncrete, but the factr f safety is 6-t7 ver the design lad. These deck panels are designed t cmply with the AASHTO HS25 requirements. Amng the applicatins develped by this manufacturer are the fllwing bridges in Ohi: the Laurel Lick Bridge, the Wickwire 48

56 Run Bridge, the Shawnee Creek Bridge, and part f the Salem Avenue Bridge. Anther bridge in their inventry is the bridge n Laurel Run Rad in Pennsylvania. Figure Superdeck bridge deck panels Hardcre Cmpsites ( This cmpany is lcated in New Castle, Delaware. Hardcre cmpsites has served mainly the marine infrastructure industry. In 1995 the manufactured their first FRP bridge deck, which was installed in Delaware. This manufacturer uses the Vacuum Assisted Resin Transfer Mlding (VARTM) prcess t manufacture their bridge deck panels, which cnsist f a hneycmb structural cre (t transfer shear) sandwiched by FRP face-skins (t prvide flexural stiffness) (Figure 3.21). The VARTM prcess allws fr the develpment f mnlithic structures, and fr the tailring f the face-skins. Their decks can be designed t satisfy AASHTO HS25 and the L/800 deflectin criterin. Hardcre cmpsites is designing and fabricating the bridges f Prject 100 (Ohi state initiative). The fllwing are the bridges manufactured by this cmpany, which are in service: Magazine Ditch Bridge (Delaware), 49

57 Washingtn Schl Huse Rad Bridge (Maryland), Muddy Run Bridge (Delaware), Bennett s Bridge (New Yrk), Wilsn s Bridge (Pennsylvania), Greenbranch Trail Bridge (Delaware), Mill Creek Bridge (Delaware), a bridge in Elmira (New Yrk), and part f the Salem Avenue Bridge (Ohi) Figure Hardcre s bridge deck panels Kansas Structural Cmpsites, Inc. ( This cmpany was frmed in 1995 and it is lcated in Russell, Kansas. The area f cncentratin f KSCI, Inc. is the applicatin f FRP bridge deck panels t deterirating highway infrastructure. Their first applicatin in cllabratin with Infrastructure Cmpsites, Internatinal (ICI) frm San Dieg, Califrnia, is the N-Name Creek Bridge in Kansas, was develped in Their deck system cnsists f a fiber reinfrced plymer hneycmb 50

58 (FRPH) cre sandwiched by cmpsite panels (Figure 3.22). This cmpany s bridge deck meets the AASHTO HS25 standard requirements. Other applicatins develped by KSCI are the tw FRP bridge decks installed n Kansas State Highway 126. Figure Crss-sectin f FRPH deck panel Martin Marietta Cmpsites, Inc. ( This cmpany is a subsidiary f Martin Marietta Materials (MMM), which is a majr supplier f aggregates in the U.S. Martin Marietta Cmpsites, Inc. (MMC) was established t pursue the applicatin f advanced cmpsites t highway infrastructure. Their bridge deck panel is the DuraSpan (Figure 3.23), which has been designed t satisfy stiffness requirements. Their main gal is t minimize the amunt f material and still satisfy AASHTO HS25 deflectin requirement. DuraSpan s gemetry uses stitched fabrics with engineered rientatins and it is fabricated using pultrusin. MMC s cmpleted and active prjects include: rad test panels (University f Califrnia, San Dieg), DARPA Task 16 Bridge (Ohi), INEEL Bridge 51

59 (Idah), Ohi s First All-Cmpsite Bridge (Ohi), King s Strmwater Channel Bridge (Califrnia), Rute 418 Truss Bridge ver Schrn River (New Yrk), and Schulyer Heim Lift Bridge (Califrnia). Figure DuraSpan deck panel 52