Epoxy Specification

7/31/2019 Epoxy Specification

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Concrete Reinforcing Steel Institu te

suggests stan da rd specifica tions

for u se in p roject docum ents

BY DAVID R GUSTAFSON

TECHNICAL DIRECTORCONCRETE REINFORCING STEEL INSTITUTE

Re c e n t l y, th e Co n c re te Re i n f o rcing Stee l In s t i t u t e(CRSI) issued a set o f suggeste d p roject spe cifica-tion s p rovisions for epox y-coate d re i n f o rcing b ars.* The

end -use provisions are inten ded to b e comp atible with

an y Am erican Concret e In stitute (ACI), Am erican Asso-

ciation of State Highwa y an d Tra n s p o rta tion Officials

( AAS H TO), or Am er ican Railwa y En g i n e e rin g Asso cia-

tion (AREA) re q u i rem en ts t hat m ight a lrea dy b e a pa rt

of a given set o f job specifications.

These CRSI p rovision s cou ld be rea dily ente red ve r b a-tim into the job specifications for p rojects where e pox y-

coa ted re i n f o rcin g ba rs are to be use d. Such pro j e c t s

m ight be tra n s p o rta tion stru c t u re s, pa rking gara g e s,

p o rt an d m arin e stru c t u re s, o r was tewa te r tre a t m e n t

p l a n t s. En g i n e e ring jud gm en t cou ld n eve rth eless be

u sed to m od ify th e re q u i rem en ts for cert ain stru c t u re s

or par ts o f stru c t u re s. For exam ple, th e limits for p erm i s-

sible coat ing d am age m ight b e inc reased for ep ox y- c o a t-

ed b ars in the walls of sewage treatmen t plan ts, since

such stru c t u res are no t sub jected to th e re p e t i t i ve m ov-

ing loads and frequen t ap plications of deicing salts tha t

b ridges expe ri e n c e.

Many of th e b asic spe cification re q u i rem en ts for un -

coated bars are also ap plicable to ep ox y-coated bars. Ex-

am ples are p re p a ration, sub mittal an d accep tance of

placing drawings; fabrication (stan dard h ooks and t ypi-

cal bar b end s); fabricating tolerance s; placing to ler-

ances; an d ove rall re q u i rem en ts for sp lices.

The CRSI Suggested Provision s for Ep ox y- Coat ed Re-

i n f o rcing Bar s for Inclusion in Pro ject Sp e c i f i c a t i o n s a re

g i ven on pa ge 810. In the com m enta ry th at follow s, th e

section num bers correspond to the section num bers in

th ose Suggest ed Prov i s i o n s.

Discussion of suggested provisions

Ge n e ral. The project specifications should include the

year of issue of each of th e ASTM specificat ion s re f e r red to.

These can be d etermin ed by checkin g th e la test An n u a l

Book of ASTM St a n d a rds, Volum e .01.04, pu blished by

th e American Society for Test ing an d Ma t e ri a l s.

1.1 The provisions for the re i n f o rcing b ars in th is sec-

tion follow t he re q u i rem en ts of th e 1983 ACI Bu i l d i n g

Code, ACI 318, Buildin g Cod e Re q u i rem en ts for Re i n -

f o rced Co n c re t e. The sp ecification s o f m an y st ate an d

f e d e ral gove rnm en t a gencies a nd oth ers curren tly have

similar re q u i rem en ts o r p resum ab ly will h ave the m .

Note that b illet-steel bars m ust also meet th e supp le-

m e n t a ry re q u i rem en t S1 o f ASTM A 615, St a n d a rd Sp e c-

Sp e c ifica t io n s fo r ep oxy-co a tedr e in fo r c in g b a r s

Epoxy-coated reinforcing bars should be fast ened wit h nylon-, epoxy-, or plastic-coated t ie wire or other accept ablematerials.


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SUGGESTED PROVISIONS FOR

EPOXY-COATED REINFORCING BARS FOR

INCLUSION IN PROJECT SPECIFICATIONS

As given in CRSI

En g i n e e rin g Da ta Re p o rt Num be r 19

1. REINFORC E M E N T

1.1 Re i n f o rcin g ba rsAll re i n f o rcin g b ar s sha ll b e de -

f o rm ed, e xcep t th at plain bars m ay be used for spira l s.

Re i n f o rcin g b ar s sha ll be th e grad es re q u i red by th eCo n t ract Docum ents a nd shall conform to on e of th e

f o l l owing sp ec ifications:

1.1.1 ASTM A 615 includ ing sup plem en tar y re q u i re-

men ts S1.

1.1. 2 ASTM A 616, e xcept that all bars sha ll be b end -

tested and shall meet the bend -test re q u i rement s for

axle-stee l re i n f o rcing ba rs, ASTM A 617, Grad e 60; an d

the ba r ma rkings rolled into th e surface of th e bars shall

include th e letter R to designate rail steel meeting th ese

re q u i re m e n t s.

1.1.3 ASTM A 617.

1.1.4 ASTM A 706 .

1.2 Ep ox y-coated re i n f o rcing ba rsWh en spe cified by

th e En g i n e e r / Architec t, ep ox y-co ate d re i n f o rcing ba rs

shall co nform to ASTM A 775. The re i n f o rcing bar s to be

e p ox y-coa ted sha ll conform to Sect ion 1 .1.

1.2.1 Repair of damaged epoxy coatingWhen re-

q u i red, dam aged epo xy coatin g sh all b e re p a i red with

patching m aterial conforming to ASTM A 775. Re p a i r

shall be don e in accordan ce with the patching m ateri a l

m a n u f a c t u re rs re c o m m e n d a t i o n s.

1.3 Bar m ats

1.3.1 Bar m ats shall conform to ASTM A 184 and shall

be fabrica ted from re i n f o rcing b ars tha t con form to Se c-

tion 1.1.

1.3.2 Bar m ats m ay b e fab ricate d from epo x y- c o a t e d

re i n f o rcin g bar s. Met al clip s sh a ll be ep ox y- c o a t e d .

Nonm etallic clips may be u sed. Coating dama ge at the

clipped or welded intersections shall be re p a i red in ac-

c o rdan ce with Section 1.2.1.

2. FAB R I C AT I O N

2.1 All re i n f o rcem en t s ha ll be be nt cold un less o the r-

wise pe rm itt ed by th e En g i n e e r / Arc h i t e c t .

3. PLACING (FIELD INSTALLAT I O N )

3.1 Ep ox y-coat ed re i n f o rcin g ba rs su pp or ted fro m

f o rm w o rk sh all rest o n coate d wire b ar sup port s, or on

bar supp orts ma de of dielectric material or other ac-cept able ma teri a l s. Wi re b ar su ppo rts sh all be coate d

with dielectric mate rial for a minimu m distan ce of 2

inch es from the po int of con tact with the ep ox y- c o a t e d

re i n f o rcing ba rs. Re i n f o rcing ba rs use d as sup por t ba rs

shall be ep ox y-coated . In walls h aving ep ox y-coated re-

i n f o rcing ba rs, spreade r b ars where specified by th e En-

g i n e e r / Arch ite ct shall be ep ox y-coa te d . Pro p ri e t a ry

comb ination bar clips an d spreaders u sed in walls with

e p ox y-coa te d re i n f o rcin g ba rs sha ll be m ad e of co rro-

s i o n - resist an t m ate ri a l .

3 . 2 Ep ox y-coated re i n f o rcing b ars shall b e fastened with

nylon-, ep ox y-, or plastic-coat ed tie wire or oth er ac-

cep table m ate ri a l s.

3.3 Splices of re i n f o rcing b ars s ha ll be m ad e o n ly as re -

q u i red or p erm itted by th e Co n t ract Docum en ts, or as

a u t h o ri zed by th e En g i n e e r / Arc h i t e c t .

3 . 3 . 1 Welded splicesWhen re q u i red or per m itted, all

welding of re i n f o rcing bar s sh all con form to AWS D1.4.

Unless otherwise perm itted, welding of crossing bars

(tack weldin g) for assem bly o f re i n f o rcem en t is p ro h i b-i t e d .

3 . 3 . 2 . Suitable ven tilation sha ll be provided when we l d-

ing ep ox y-coa ted re i n f o rcin g bars.

3 . 3 . 3 After com pletion of welding on e pox y-coated re-

i n f o rcing ba rs, co atin g d am age sha ll be re p a i red in ac-

c o rda n ce with Sect ion 1.2.1. All we l d s, a n d all st ee l

splice m embe rs when u sed to splice ba rs, shall be coat-

ed with the sam e ma terial used for repair of coating

d a m a g e.

3 . 3 . 4 Mechan ical conn ectionsWhen re q u i red or per-

mitte d, mechan ical con nection s shall be installed in ac-

c o rdance with th e sp lice de vice m anu facture rs re c o m -

m e n d a t i o n s.

3 . 3 . 5 After installing m echa nical con nection s on epox y-

coat ed re i n f o rcing b ars, coatin g d am age shall b e re-

p a i red in acco rdan ce with Section 1.2.1. All part s of me -

chan ical conn ections used on coated ba rs, including

steel splice sleeve s, bolts an d n uts sh all be coa ted with

the same m aterial used for repair of coating dama ge.

3 . 4 Re i n f o rcing bar s p art ially em bed de d in con cre t e

shall not be field b ent, except as indicated on the Co n-

t ract Docu me nt s or per mitte d by th e En g i n e e r / Arc h i-

tect. When heat is used to field b end epox y-coated re-

i n f o rcing ba rs, s uita ble vent ilation sha ll b e p rov i d e d .

When ep ox y-coate d re i n f o rcing bar s are field ben t,

coatin g da ma ge shall be re p a i red in a ccorda nce withSection 1.2.1.

3 . 5 Unless pe rm itte d by th e En g i n e e r / Archite ct, re i n-

f o rcing ba rs sha ll not b e cu t in th e field. When ep ox y-

coate d re i n f o rcing ba rs are cut in t he field, th e e nd s of

the bars shall be coated with the same m aterial used

for repair of coating dam age.

3 . 6 Ep ox y-coa ted re i n f o rcing ba rsEqu ipm en t for han -

dlin g epox y-coated bars shall have protecte d co ntact

a re a s. Bundles o f coated bars shall be lifted at m ultiple

pickup po ints to m inimize bar-to-b ar abrasion fro m

sags in the bun dles. Coated bars or bu ndles of coated

bars shall not be dropp ed or dragged. Coated bars shall

be stored on pro t e c t i ve crib bing. Fading of the color o fthe coating sh all not be cause for rejection o f epox y-

coate d r e i n f o rcing b ars. Coating d am age d ue to h an -

dlin g, shipmen t an d placing nee d not be re p a i red in

cases where the dam aged area is 0.1 squa re inch or

s m a l l e r. Dam aged area s larger tha n 0.1 squ are inch

shall be re p a i red in accorda n ce with Section 1.2.1. The

m aximu m am ou nt of dam age includ ing re p a i red an d

u n re p a i red areas shall n ot exceed 2 perce nt of th e sur-

face area o f each ba r.


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ificat ion for De f o rm ed an d Pla in Bi l l e t - Steel Bars for

Co n c rete Re i n f o rc e m e n t .

Also n ot e t he special b en d test re q u i rem en ts for ra i l -

steel ba rs. For re i n f o rcing ba rs, th e type of st eel an d

g rade (min imum yield strength) mu st be specified in the

Co n t ract Docum en ts for all p ro j e c t s.

Oth er spe cification s cited for re i n f o rcing b ars are :

ASTM A 616, St a n d a rd Specificat ion for Ra i l - Steel De -

f o rm ed and Pla in Bars for Co n c re te Re i n f o rc e m e n t ;

ASTM A 617, St a n d a rd Sp ecificat ion for Axle-Stee l De -f o rmed an d Plain Bars for Co n c rete Re i n f o rc e m e n t; and

ASTM 706, St a n d a rd Spe cifica t ion for Low - Al l oy St e e l

De f o rm ed Bars for Co n c rete Re i n f o rc e m e n t . The En g i-

n e e r / Arch itect sho uld investigat e whe th er ASTM A 706

re i n f o rcing ba rs are available locally be fore sp ecifying

t h e m .

Since th is re p o rt is concern ed on ly with epox y- c o a t e d

re i n f o rcing ba rs, t he oth er kind s of re i n f o rcem en t such

as wire and welded w ire fabric are n ot includ ed in Se c-

tion 1.1.

1.2 This section gives th e p rovision s for specifyin g

e p ox y-coated bar s an d, when re q u i red in sub sequ ent

s e c t i o n s, th e provisions for repa ir o f d am aged coat ing.To m eet th e ACI Building Code an d ot her cod es an d

s p e c i f i c a t i o n s, the ba rs tha t are to be coat ed m us t m eet

th e re q u i rem en ts in Section 1.1. This is anoth er re a s o n

for inc ludin g t he sp ecific re q u i rem en ts for re i n f o rc i n g

ba rs in these sugges ted prov i s i o n s, par ticu larly for billet-

and ra il-stee l b ars. ASTM A 775, St a n d a rd Sp e c i f i c a t i o n

for Ep ox y- Coa ted Re i n f o rcin g Steel Ba r s, d oes n ot in -

clude the add itiona l re q u i rem en ts for b illet- an d ra i l -

steel bars wh ich are given in Sections 1.1.1 and 1.1.2, re-

s p e c t i ve l y.

On pro jects wh ere bo th un coat ed an d ep ox y- c o a t e d

re i n f o rcing b ars are used , the En g i n e e r / Arch itect sh ou ld

be p recise in identifying those bars th at are to be coat-e d .

1.3 The cu rren t ASTM A 184, St a n d a rd Sp e c i f i c a t i o n

for Fa b ricat ed De f o rm ed Steel Bar Mats for Co n c rete Re-

i n f o rc e m e n t , do es no t include ep ox y-coate d ba rs. It is

an ticipa ted th at ASTM A 184 will be revised soon . Un t i l

th at revision is accom plished, Section 1.3.2 of the Su g-

geste d Prov i s i o n s p rovides for m ats fab ricat ed fro m

coated bars. ASTM A 184 perm its fabrication of ma ts by

clip ping or welding the ba r int ersections. For certain ap -

pl icat ion s th e En g i n e e r / Arch itect m ay wish to re s t ri c t

the fabrication of bar m ats to the clipped t ype only.

2.1 ASTM A 775 (title given ab ove) co nt ain s p rov i s i o n s

for r epa ir o f coa ting d am age resultin g from fabri c a t i o n .

The reason for including Section 2.1 is to em ph asize tha t

all re i n f o rcing bars, u nco ated an d coated , m ust be ben t

cold un less o th erwise pe rm i t t e d .

3.1 As po inted ou t in CRSI Engineerin g Da ta Re p o rt

Number 14 [and in ou r article based on it cited in the

foot no te on page 809Editor], the re h ave b een re p o rt s

of problem s and m isund erstandings in furnishing bar

s u p p o rts for ep ox y-coat ed ba rs b ecau se o f the ap pa re n t

lack of specification s. The su ggested p rovisions in Se c-

tion 3.1 are inten ded to clarify the issue of bar sup port s.

If epox y-coated re i n f o rcing ba rs are re q u i red for both th e

top an d b ottom mats in slabs or bridge decks, for exam -

p l e, the en tire wire bar su pp ort sh ould b e coated .

Detailing of side form sp acers is not a stan dard re -

q u i rem en t a nd is p erf o rm ed on ly when spe cifically re-

q u i red by the Co n t rac t Docu m en ts (see ACI Co m m i t t e e

315, ACI Detailing Manual, 1980, Publication SP-66,

pu blished by Am erican Co n c rete Inst itute). Thu s the En-g i n e e r / Architec t m u st sp ecify side-form spacers includ -

ing m ate rial, coat ing (if re q u i red), t ype, sp acing and lo-

ca tion wh ere re q u i re d .

Sp reader b ars for walls, whether un coated or coated ,

m ust b e sp ecified in th e Co n t ract Docum en ts by the En-

g i n e e r / Arc h i t e c t .

3.2 To minim ize dam age, or cuttin g int o the b ar coat-

ing, som e type of coated tie wire shou ld be used for

tieing assem blages of ep ox y-coated bars.

3.3 This section con tains p rovision s for welded sp lices

and m echan ical conn ections of coated b ars. The cu rre n t

AWS D 1.4 St ru c t u ra l Weld ing Co d e Re i n f o rcin g St e e l

(pub lished by Am erican Welding Society) conta ins asafety p recau tion for we lding zin c-coat ed (galva n i ze d )

re i n f o rcin g b ars bu t n ot for e p ox y-coa ted ba rs. Od o r s

an d fum es resu lt from he ating an d welding epox y- c o a t-

ed ba rs. For this reaso n it is p rud en t, un til the we l d i n g

code is revised, to include a suggested clause th at su it-

ab le ven tilation (Section 3.3.2) be prov i d e d .

AWS D1.4 does n ot p erm it welding of crossing bars for

assembly of re i n f o rcem en t (ta ck weldin g) un less aut ho -

ri zed by t he En g i n e e r. Howe ve r, it is re com m en ded th a t

this prohibition be em ph asized in the p roject specifica-

tion s b y inclu din g Section 3.3.1 in them . A CRSI re f e r-

en ce state s: Ne ver perm it field welding of crossing bars

( t a c k weldin g, s p o t weld ing an d so forth ). Tie wire willdo the job without h arm t o the b ars. (Re i n f o rcement An -

c h o ra ges and Splices, Second edition , 1984, Co n c rete Re-

i n f o rcing Steel In s t i t u t e. )

For certain types of splice de vices, the sup plier might

p refer to coa t the steel splice sleeves and other parts o f

the m echanical conn ections with the sam e coating ma -

t e rial, app lied by the sam e m etho d, as used for the

e p ox y-coate d re i n f o rcing ba rs. Th is p rac tice m ight be

m o re cost effective, esp ecially for larger p ro j e c t s, a nd

would certainly be acceptab le.

3.4 If coated bars p artially em bedded in con crete are

field b ent, the dam aged co ating m ust be re p a i red in ac-

c o rdan ce with Section 1.2.1. Guidelines for field b end ing

of bars p artially emb edd ed in con crete are given in AC I

318R, Co m m e n t a ry o n Bu ild ing Code Re q u i rem en ts for

Re i n f o rced Co n c re t e. If heat is u sed for such field b en d-

ing, as suggested by t he Co m m e n t a ry, it is p rud en t to

includ e a p rovision re q u i ring ventilation wh en ep ox y-

coated bars a re heated , as was d iscussed above for we l d-

i n g .

3.5 Field cu ttin g of re i n f o rcing ba rs, whe ther un coat -


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ed or coated , shou ld b e don e on ly if perm itted by the En-

g i n e e r / Arch itect. If ep ox y-coat ed re i n f o rcin g bars are

field-cut, the ends of the bars must be coated with

pa tch ing m ater i a l .

3.6 These suggested p rovisions are inten ded to m ini-

m i ze coating da m age du ring ha nd ling an d field p lacing

o p e ra t i o n s, a n d to set limits on pe rm issible coa ting

dam age an d repa ir of dam aged coa ting. The pe rm i s s i b l e

coating d am age is com patible with the re q u i rem ent s of

ASTM A 775 for coat ing dam age su ffere d in fab ri c a t i o nor ha ndling t o the po int of sh ipm en t. Si m i l a r l y, the limit

on the m axim um am oun t of dam age, includ ing re p a i re d

and un re p a i red a re a s, is comp atible with t he sam e sp ec-

ificat ion . As re p o rt ed in CRSI Engin eerin g Da ta Re p o r t

Number 14, som e epoxy coatings m ay fade in color whe n

the coated bars are exposed to sun light over a period of

t i m e. Since t his fading does not har m the coating, a pro-

vision is includ ed to clarify th e fact.

Editors note:

This article is condensed from Suggested Project Specifi-cations Provisions for Epoxy-Coated Reinforcing Bars, CR-SI Engineering Data Report Number 19. Copies of that re-port and other CRSI publications referred to in this articleare available from Concrete Reinforcing Steel Institute, 933North Plum Grove Road, Schaumburg, Illinois 60195.

Sources of other documents referred to in this article are:American Concrete Institute, Box 19150, Detroit, Michigan48219; American Society for Testing and Materials, 1916Race Street, Philadelphia, Pennsylvania 19103; and Ameri-can Welding Society, 2501 N.W. Seventh Street, Miami,Florida 33125.

Coated bars should be stored on protect ive cribbing. Nylon

st raps are used in bundling bars to avoid damaging the barcoating.

PUBLICATION #C840809

Co py right 1984, The Ab e rde en Gro u p

All righ ts re s e rve d

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