HomeMy WebLinkAboutPROJECT INFORMATIONProduct Data Sheet SCANNED
Edition 7.14.2014 BY
Sikacrete® 211 St. Lucie Countv.
8ekaerete° 211 ;
One -component, cementitious,
pumpable and pourable concrete mix
Description Sikacrete® 211 is a 1-component, portland-cement concrete containing factory blended
coarse aggregate.
Where to Use ■ Full depth repairs.
n On grade, above, and below grade on concrete.
o On horizontal, vertical and overhead surfaces.
■ As a structural repair material for parking facilities, industrial plants, walkways, bridges,
tunnels, dams and balconies.
■ Filler for voids and cavities.
Advantages n Pre -packaged coarse aggregate: Eliminates need to extend material In the hela; thmI-
nates the risk of reactive aggregate.
■ High bond strength.
. Compatible with coefficient of thermal expansion of concrete.
■ Increased resistance to deicing salts.
■ Simple -to -use labor-saving system.
. Easily mixed.
■ Good freeze/thaw resistance. _
. Easily applied to clean, sound substrate.
■ Not a vapor barrier.
■ Not Flammable
Coverage Approximately 0.65 R'/unit
Packaging 80 lb. multi -wall bag. ,
PRIOR TO EACH USE OF ANY SIKA PRODUCT, THE USE - - . No FOLIMM THE WARNINGU=
INSTRUCTIONS ON THE PRODUCTS MOST CURRENT PRODUCT DATA SHEET, PRODUCT LABEL AND SAFETY DATA
SHEET WHICH ARE AVAILABLE ONLINE AT HTTP:lNSA.SIKA.COMI OR BY CALLING SIKA'S TECHNICAL SERVICE DE-
PARTMENTAT S00.933.7492 NOTHING CONTAINED IN ANY SIKA MATERIALS RELIEVES THE USER OF THE OBLIGATION
TO READ AND FOLLOW THE WARNINGS AND INSTRUCTIONS FOR EACH SIKA PRODUCT AS SET FORTH IN THE CUR-
RENT PRODUCT DATA SHEET, PRODUCT LABEL AND SAFETY DATA SHEET PRIOR TO PRODUCT USE.
A130
How to
W'A Substrate Concrete, mortar, and masonry products.
I Surface Preparation Concrete: Remove all deteriorated concrete, dirt, oil, grease, and all bond -inhibiting materials
from surface. Be sure repair area is not less than 1 in. in depth. Preparation work should be
= donebyhighpressurewaterblast,scabbier, orotherappropriatemechanicelmeanstoobtain
an exposed aggregate surface with a minimum surface profile of t1/8 in. (CSP-7). Saturate
+' surface with clean water. Substrate should be saturated surface dry (SSD) with no standing
e water during application.
Reinforcing Steel: Steel reinforcement should, be thoroughly prepared by mechanical cleaning
to remove all traces of rust. Where corrosion has occurred due to the presence of chlorides, the
steel should be high-pressure washed With clean water after mechanical cleaning. For priming of
reinforcing steel use Sika®Annate& 11O EpoCem (consult Technical Data Sheet).
Primina For priming of reinforcing steel use Sika®ArmatecF110 EpoCem (consult Technical Data Sheet).
Mixing
Place 415 of 1 gallon water in mixing container. Add Sikacrete® 211 while continuing to mix.
Add additional water up to 1 gallon total. Mix to a uniform consistency, maximum 3 minutes.
tqf
Mechanically mixwith a low -speed drill (400-600 rpm) and paddle orin appropriate size mortar
mixer or concrete mixer.
Application
Form and pour or pump applications: Pre -wet surface to SSD. Ensure good intimate con-
vt,�I
tact with the substrate is achieved. To accomplish this, material should be scrubbed into the
as
substrate or other suitable means should be employed such as vibration of the material or
.+
pumping under pressure. Vibrate form while pouring or pumping. Pump with a variable pres-
Pf
sure pump. Continue pumping until a 3 to 5 psi increase in normal line pressure is evident
then STOP pumping. Form should not deflect. Ventto be capped when steady flow is evident,
1L;
and forms stripped when appropriate
for curing is required. Moist cure
Tooling & finishing
As per ACI recommendations portland cement concrete,
with wet burlap and polyethylene, a fine mist of water or a water based* compatible curing
1 - • -
compound. Curing compounds adversely affect the adhesion of following layers of mortar,
leveling mortar or protective coatings. Moist curing should commence immediately after fin-
ishing. Protect newly applied material from direct sunlight, wind, rain and frost.
1 A
•Pretesting of cuMg compound Is recommended.
Maximum 8 in.
Limitations
at Application thickness: Minimum 1 in. (25 mm); (200 mm)
atMinimum ambient and surface temperatures 45°F (7°C) and rising at time of application.
It
■ Using Sika Latex®, Sikal-atel R or similar products will result in loss of slump and slump
retention. Field tests for suitability are strongly recommended.
PRIOR TO EACH USE OF ANY SIKA PRODUCI, THE USER MUST ALWAYS READ AND FOLLOW THE WARNINUS ANU
INSTRUCTIONS ON THE PRODUCTS MOST CURRENT PRODUCT DATA SHEET, PRODUCT LABEL AND SAFETY DATA
SHEET WHICH ARE AVAILABLE ONLINE AT HTTP:IAISA.SIKA.COM/ OR BY CALLING SIKA'S TECHNICAL SERVICE DE
PARTMENTAT 800.933.7462 NOTHING CONTAINED IN ANY SIKA MATERIALS RELIEVES THE USER OF THE OBLIGATION
O READ AND FOLLOW THE WARNINGS AND INSTRUCTIONS FOR EACH SHIA PRODUCT AS SET FORTH IN THE CUR
RENT PRODUCT DATA SHEET, PRODUCT LABEL AND SAFETY DATA SHEET PRIOR TO PRODUCT USE.
IIEEEPCOMAINMVGRRYCLOSM.REEPOWOFREACHOFCMLDREN.NOTFORINTENN0.LCONS MPTIOKFORINDUSTRIALU5EONLY.FORPROFESYOMLUSEONLY.
For further Information and advice regarding transportation, handling, storage and disposal of chemical products, users should refer to the
actual Safety Data Sheets containing physical, ecological, toxicological and other safety related data. Read the current actual Safety Data Sheet
before using the product. In case of emergency, call CHEMTREC at 1-800424-9300, International 703-V2 87.
Prior to each use Pfanv SIM Product the usermust always read and follow no warnings and Instructions on the product's most current Product
for each Sika product as sat /orih In the current Product Data Sheet product label and Safety Data Sheet prior to
product use.
Regional Information and Sales Centers. For the location of your nearest Sika sales oigcs, contact your regional center.
Sills Corporation Sills Canada Inc. Sika Mexicans S.A. do C.V.
201 Polito Avenue 801 DelmarAvenue Cartelers Libre Celaya Ken. 8.5 �sf� e
Lyndhurst, NJ 07071 Pointe Claire Frl Industrial m l 9alvane
Phone: 800-933-7452 Quebec HOR 4A9 Comegldora, Queretaro usrou ia,Fr.T
For. 201-933-61 Phone: 514-697-2610 C.P. 76920 -
Fax:514-694-2792 Phone: 52 442 2385800 SMmd SikaaMe are registered
Fax: 52 442 2250537 trademarks. Panted in Canada.
TECHNICAL
} GUIDELINES
l Prepared by the International Concrete Repair Institute December 2008
Guide for Surface
Preparation for the
Repair of Deteriorated
Concrete Resulting
from Reinforcing
Steel Corrosion
Guideline No. 310.1 R-2000 (formerly No. 03730)
Copyright 0 2008 International Concrete Repair Institute
All rights reserved.
International Concrete Repair Institute
3166 S. River Road, Suite 132, Des Plaines, IL 60018
Phone: 847-827-0830 Fax: 847-827-0832
Web site: wm .icrl.org
E-mail: info@icri.org
�INTERNATIONAL
a"ICIII CONCRETE REPTIE
INSTITUTE
\\V
About ICRI Guidelines
The International Concrete Repairinstitute (ICRI)
wasfounded to improve the durability of concrete
repair and enhance its value for structure owners.
The identification, development, andpromotion of
the most promising methods and materials are
primary vehicles for accelerating advances in
repair technology. Working through a variety of
forums, ICRI members have the opportunity to
address these issues and to directly contribute to
improving the practice of concrete repair.
A principal component of this effort is to make
carefully selected information on important repair
subjects readily accessible to decision makers.
During the past several decades, much has been
reported in the literature on concrete repair
methods and materials as they have been developed
and refined Nevertheless, it.'has been difficult to
i find critically reviewed information on the state of
the art condensed into easy -to -use formats.
To that end, ICRI guidelines are prepared by
sanctioned task groups and approved by the ICRI
TechnicalActivitiesCommittee. Each guideline is
designed to address a speck area of practice
recognized as essential to the achievement of
durable repairs. AIt 1CRIguideline documents are
subject to continual review by the membership and
may be revised as approved by the Technical
Activities Committee.
Technical Activities Committee
Kevin Michels, Chair
Jim McDonald, Secretary
Randy Beard
Don Caple
Bruce Collins
William `Bud" Earley
Don Ford
Tim Gillespie
Peter Golter
Peter Lipphardt
David Rodler
Michael Taliassi
David Whitmore
Pat Winkler
Producers of this Guideline
Surface Preparation Committee
Pat Winkler, Chair*
Dan Anagnos
Randy Beard
Bruce Collins
William "Bud" Earley
Peter Emmons*
Andrew Fulkerson
Randy Glover
Fred Goodwin*
Kurt Gottinger
Tyson Herman
Dave Homerding
Bob Johnson
David Karins
Ken Lozen*
Jim McDonald
Beth Newbold
Jeffery Smith
Sandra Sprouts
Rick Toman
Patrick Watson
*Contributing editors
Synopsis
This guideline provides guidance on concrete
removal and surface preparation procedures for
the repair of deteriorated concrete caused by
reinforcing steel corrosion. Removal geometry,
configuration ofthe repair area, removal process,
edge preparation, reinforcement repair, surface
preparation and inspection necessary for durable
repairs are discussed. Special considerations for
concrete removal associated with column repair
are included.
Keywords
anodic ring effect, bonding, bruising, corrosion,
delamination, deterioration, reinforcing steel,
structural repair, surface preparation.
This document is intended as a voluntary guideline for the owner, design professional, and
concrete repair contractor. It is not intended to relieve the professional engineer or designer
of any responsibility for the specification of concrete repair methods, materials, or practices.
While we believe the information contained herein represents the proper means to achieve
quality results, the International Concrete Repair Institute must disclaim any liability or
responsibility to those who may choose to rely on all or any part of this guideline.
310.1 R-2008 GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OF DETERIORATED CONCRETE RESULTING FROM REINFORCING STEEL CORROSION
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Contents
1.0
Introduction..............................................................................................................................1
2.0
Definitions...............................................................................................................................1
3.0
Exposure of Reinforcing Steel..................................................................................................1
4.0
Anodic Ring (Halo) Effect.........................................................................................................2
5.0
Removal Geometry .................................................................................................................2
6.0
Configuration of Repair Area...................................................................................................3
7.0
Concrete Removal/Surface Preparation...................................................................................3
7.1 Exposing and Undercutting of Reinforcing Steel..................................................................3
7.2 Preparation of the Repair Perimeter....................................................................................4
7.3 Cleaning of the Concrete Surface and Reinforcing Steel.....................................................4
8.0
Inspection and Repair of Reinforcing Steel.............................................................................5
9.0
Final Surface Inspection.........................................................................................................5
10.0
Special Conditions at Columns ........ ................................................ ........................................
6
11.0
Summary ................................................................................................................................7
12.0
References ................ ......... ............ .......................... .... ....... ................ ....... ....
.... .......... ......... ...7
12.1 Referenced Standards and Reports....................................................................................7
fzn
GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OF DETERIORATED CONCRETE RESULTING FROM REINFORCING STEEL CORROSION 310.1 R-2008
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310.111-2008 GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OF DETERIORATED CONCRETE RESULTING FROM REINFORCING STEEL CORROSION
1.0 Introduction
This guideline provides owners, design profes-
sionals, contractors, and other interested parties
with a recommended practice for the removal of
deteriorated concrete caused by the corrosion of
reinforcing steel, including the preparation of the
removal cavity to provide a clean sound surface
to bond a repair material.
This guideline outlines removal geometry,
configuration, removal process, edge preparation,
reinforcement repair, surface preparation, and
inspection prior to placing a repair material. An
engineer should evaluate the impact of concrete
removal on structural capacity priorto performing
concrete removal and repair. The repair methods
involve saw cutting and concrete removal using
impact tools, hydrodemolition, and other removal
techniques. Special caution should be taken to
locate and avoid cutting or damaging embedded
reinforcing bars, prestressing strands, post -
tensioning tendons, or electrical conduits. Cutting
into these items can be life threatening and may
significantly affect structural integrity.
This guideline also contains a discussion of
concrete removal and preparation for the repair
of columns where the concrete is in compression.
Special consideration must be given to the repair
of concrete in compression as the load -carrying
capacity of the element may be permanently
compromised during the concrete removal and
preparation process.
While the procedures outlined herein have
been used to successfully remove concrete and
prepare the removal cavity on many projects, the
requirements for each project will vary due to
many different factors. Each project should be
evaluated individually to ascertain the applicability
of the procedures described herein. Refer to ACI
506R-05, "Guide to Shotcrete" for surface prepar-
ation prior to shoterete application.
2.0 Definitions
Anodic ring effect: Corrosion process in which
the steel reinforcement in the concrete surrounding
a repaired area begins to corrode preferentially
to the steel reinforcement in the newly repaired
area (sometimes referred to as the halo effect).
Bruised surface (micro -fracturing): Asurface
layer weakened by interconnected microcracks
in concrete substrates caused by the use of high -
impact, mechanical methods for concrete
removal, and surface preparation; fractured layer
ION
A CONCRETE REPAIR
INSTITUTE
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typically extends to a depth of 0.13 to 0.38 in.
(3 to 10 mm) and, if not removed, frequently
results in lower bond strengths as compared with
surfaces prepared with nonimpact methods.
Carbonation: The conversion of calcium ions
in hardened cementitious materials to calcium
carbonate by reaction with atmospheric carbon
dioxide. Carbonation reduces the pH of the
concrete and its ability to protect reinforcing steel
and embedded metal items from corrosion.
Chloride contamination: Contamination of
concrete with chloride ions commonly used in
deicing salts and accelerating admixtures such as
calcium chloride and sodium chloride. Chloride
contamination above the threshold for corrosion
can result in corrosion of the reinforcing steel.
Chloride threshold: The amount of chloride
required to initiate steel corrosion in reinforced
concrete under a given set of exposure conditions;
commonly expressed in percent of chloride ion
by mass of cement.
Corrosion: Degradation of concrete or steel
reinforcement caused by electrochemical or
chemical attack.
Microcrack: A crack too small to be seen with
the unaided eye.
Tensile pulloff test: A test to determine the
unit stress, applied in direct tension, required to
separate a hardened repair material from the
existing concrete substrate. The test may also be
used to determine the maximum unit stress that
the existing concrete substrate is capable of
resisting under axial tensile loading and the near -
surface tensile strength of a prepared surface
(refer to ICRI Technical Guideline No. 210.3-
2004 (formerly No. 03739] and ASTM C1583).
Substrate: The layer immediately under a
layer of different material to which it is typically
bonded; an existing concrete surface that receives
an overlay, partial -depth repair, protective coating,
or some other maintenance or repair procedure.
3.0 Exposure of
Reinforcing steel
The practice of completely removing the concrete
(undercutting) from around the corroded
reinforcement, no matterwhat degree of corrosion
is found, is key to achieving long-term performance
of surface repairs. In most cases, complete
removal of the concrete from around the
reinforcing steel is the best practice, where
protection of the reinforcing steel within the
GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OF DETERIORATED CONCRETE RESULTING FROM REINFORCING STEEL CORROSION 310.114-2008-1
INT[RNATIONAL
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repair cavity is achieved by providing a uniform
chemical environment around the reinforcing
steel. If noncorToded reinforcing steel is exposed
and the concrete is chloride contaminated,
removal of the concrete around the reinforcing
should occur or other corrosion -reducing means
should be considered. Reinforcing steel partially
embedded in chloride -contaminated concrete is
susceptible to future accelerated corrosion.
If, for structural reasons, the concrete cannot
be completely removed from around the corroded
reinforcing steel or if a corrosion inhibiting
system is not used, the repairmay be compromised
due to continued corrosion. If there is a potential
trade-off between durability and structural
capacity, structural capacity should always take
priority. When reinforcing steel is not fully
exposed through the concrete removal and
preparation process, alternative corrosion inhib-
iting systems should be considered. These
systems may include use of corrosion inhibitors,
sacrificial anodes, or cathodic protection.
4.0 Anodic Ring
(Halo) Effect
The existing concrete surrounding a repair area
in chloride -contaminated or low pH reinforced
concrete is susceptible to accelerated corrosion.
This is due to the electrical potential differential
between the chloride contaminated or low pH
existing concrete and the chloride -free or
high pH repair material. This anodic ring effect
can result in accelerated corrosion of the
surrounding reinforcing steel leading to future
concrete deterioration. To assess existing concrete
conditions beyond the repair area, chloride
content and pH of the concrete at the level of the
reinforcing steel should be determined. Where
the chloride content exceeds the threshold level
for the initiation of corrosion or where the
reinforcing steel is susceptible to corrosion as a
result of carbonation, a corrosion inhibiting
system should be considered to minimize future
corrosion. Othermeasures may also be considered,
such as the application of sealers and coatings, to
slow the corrosion process. In severely chloride -
contaminated or carbonated concrete, the
complete removal and replacement of the
contaminated concrete at and beyond the repair
area may be necessary to provide a successful
long-term repair.
Examples of the removal geometry for several
different types of reinforced concrete elements
are shown in Fig. 5.1 through 5.6. Repairs may
be located on horizontal, vertical, and/or overhead
surfaces. The removal in Fig. 5.5 and 5.6 is for
columns where the removal will not affect the
structural capacity of the column. Removal of
concrete within the reinforcing or to expose the
reinforcing (concrete in compression) is a special
condition and is discussed in Section 10.
10 0161IMIf
Fig. 5.1: Partial depth repair, slab or wall, section
Fig. 5.2: Fall depth repair, slab or wall, section
2-310.113-2008 GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OF DETERIORATED CONCRETE RESULTING FROM REINFORCING STEEL CORROSION
11
Fig. 5.3: Beam or rib repair, elevation
Fig. 5.4: Beam or rib repair, section
Fig. 5.5: Column repair, elevation
Fig. 5.6: Column repair, section
F I
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Deteriorated and delaminated concrete should be
located and marked prior to starting the removal
process. Delaminated concrete can be located using
sounding or other suitable techniques. The repair
area should extend a minimum of 6 in. (152 min)
beyond the actual delaminated concrete. Note that
during concrete removal, repair areas can grow
in size beyond the areas identified due to incipient
delaminations that are not readily identifiable
by sounding. Repair configurations should be
kept as simple as possible, preferably square or
rectangular with square comers (Fig. 6.1). This may
result in the removal of sound concrete. Reentrant
comers should be minimized or avoided, as they
are susceptible to cracking.
Fig. 6.1: Areas ofdeterioration and
recommended removal configurations
7,0 Concrete
Removal/Surface
Preparation
7.1 Exposing and
Undercutting of
Reinforcing Steel
Remove concrete from the marked areas and
undercut exposed reinforcing steel (Fig. 7.1) using
impact breakers, hydrodemolition, or another
suitable method. Undercutting will provide
clearance under the reinforcing steel for cleaning
and full bar circumference bonding to the repair
material and the surrounding concrete. Bonding
GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OF DETERIORATED CONCRETE RESULTING FROM REINFORCING STEEL CORROSION 310.1 R-2008 - 3
4 -•aea
INTERNATIONAL
CONCRETE
REPAIR
I N S T I T U T E
the repair material to the full circumference of the
reinforcing steel will secure the repair structurally.
Provide a minimum of 0.75 in. (19 mm) clearance
between exposed reinforcing steel and surrounding
concrete or 0.25 in. (6 mm) larger than the coarse
aggregate in the repair material, whichever is
greater. Sound concrete may have to be removed
to provide proper clearance around the reinforcing
steel. If impact breakers are used for partial depth
concrete removal, the breaker should not exceed
30 lb (12 kg). A 15 lb (7 kg) breaker is preferred
Fig. 7.1: Remove concrete to undercut
and expose reinforcing steel and
provide uniform repair depth
Fig. 7.2: Saw cut perimeter
to provide vertical edge
Fig. 7.3: Abrasive blasting to clean
substrate and reinforcing
to minimize damage to the substrate, reinforcing
steel, and surrounding concrete.
Concrete removal should extend along the
reinforcing steel until there is no further delam-
ination, cracking, or significant corrosion and the
reinforcing steel is well bonded to the surrounding
concrete. Care should be taken to avoid significant
and sudden changes in the depth of concrete
removal, as the repair material is more susceptible
to cracking at these locations.
If noncorroded reinforcing steel is exposed
during the removal process, care should be taken
to not damage the bond to the surrounding
concrete. If the bond between the reinforcing
steel and concrete is broken, undercutting of
the reinforcing steel is required.
Remove all deteriorated concrete and additional
concrete as required to provide the proper
configuration and/or the minimum required
thickness of repair material as required by the
manufacturer of the repair material and/or the
project specifications.
7.2 Preparation of the
Repair Perimeter
The perimeter of the repair area should be saw
cut 0.75 in. (19 mm) deep to provide a vertical
edge (Fig. 7.2) for the repair material. This will
avoid featheredging of the repair material.
Depending on the repair material selected, the
depth of the existing reinforcing and the
manufacturer's recommendations, a saw cut depth
less than 0.75 in. (19 mm) deep may be sufficient.
Care should be taken to avoid cutting the existing
reinforcing steel.
7.3 Cleaning of the
Concrete Surface and
Reinforcing'Steel
The use of high -impact, mechanical methods to
remove deteriorated concrete will result in a
surface layer weakened by interconnected micro -
cracks in the concrete substrate. The fractured
(bruised) layer can extend to a depth of 0.125 to
0.375 in. (3 to 10 mm) into the resultant concrete
substrate and may result in reduced bond strength.
Remove the bruised layer and bond -inhibiting
materials such as dirt, concrete slurry, and loosely
bonded concrete by oil -free abrasive blasting
(Fig. 7.3) or high-pressure water blasting. The
4 - 310.1 R-2008 GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OF DETERIORATED CONCRETE RESULTING FROM
saw -cut edge of the repair area should also be
blasted to roughen the polished vertical surface
caused by the saw -cutting.
All concrete, corrosion products, and scale
should be removed from the reinforcing steel by
oil -free abrasive blasting or high-pressure water
blasting. Verify that the reinforcing steel and
concrete surface are free from dirt, oil, cement
fines (slurry), or any material that may interfere
with the bond of the repair material. Inspect the
repair cavity to verify that all delaminations and
deterioration have been removed. If hydro -
demolition is used, cement fines (slurry) must be
completely removed from the repair surface. A
tightly -bonded light rustbuild-up onthe reinforcing
surface is usually not detrimental to bond. If a
protective coating is applied to the reinforcing
steel, follow the coating manufacturer's recom-
mendations for steel surface preparation.
8.0 Inspection
and Repair of
Reinforcing Steel
Loose reinforcement should be secured in its
original position by tying to secure bars or by
other appropriate methods to prevent movement
during placement of repair material.
If reinforcing steel has lost cross -sectional
area, a structural engineer should be consulted.
Repair reinforcing steel by either replacing the
'L INTERNATIONAL
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REPAIR
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damaged/deteriorated steel or placing supple-
mental reinforcing steel in the affected section
(Fig. 8.1). Supplemental reinforcing steel may be
lap -spliced or mechanically spliced to existing
reinforcing steel. The supplemental reinforcing
steel should extend (lap length) beyond the
damaged/deteriorated area in accordance with
ACI 318, "Building Code Requirements for
Structural Concrete."
9.0 Final Surface
Inspection
Immediately prior to placing the repair material,
inspect the repair cavity to verify that all bond -
inhibiting materials (dirt, concrete slurry, loosely
bonded aggregates, or any material that may
interfere with the bond ofthe repair material to the
existing concrete) have been removed. If bond -
inhibiting materials are present, the repair cavity
should be recleaned as previously described.
To verify the adequacy of the prepared
concrete surface and completeness of bond -
inhibiting material removal, a tensile pulloff test
(ICRI Technical Guideline No. 210.3-2004 or
ASTM C1583) should be considered to evaluate
the bond strength capacity and tensile strength of
the existing concrete substrate. This test may also
be performed after the repair is complete. The
pulloffstrength requirement should be established
by the engineer and included as a performance
specification for the repair.
Affected Length
Fig. 8.1: Repair of damagedldeteriorated reinforcing
GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OF DETERIORATED CONCRETE RESULTING FROM REINFORCING STEEL CORROSION 31OAR-2008-5
INTERNATI6NAL
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Fig. 10.1: Column load path Fig. 10.2a: Column repair Fig. 10.3: Column load
path following repair
Fig. 10.2b: Column section
6-310.1R-2008 GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OF DETERIORATED
Undercutting of reinforcement is a best practice
in tensile zones of concrete. In columns, the
primary loading condition is compression. From
a design perspective, the concrete section
contained within the reinforcing cage is considered
to carry the compressive loads (Fig. 10.1). The
concrete outside ofthe reinforcement is considered
as protective concrete cover for fire and corrosion
protection of the reinforcement. Removing the
concrete within the column reinforcing steel
(Fig. 10.2) can greatly increase the compressive
stress in the reinforcing steel and the remaining
concrete. Upon concrete removal, compressive
load paths redistribute around the repair
(deteriorated) sections (Fig. 10.3). Depending on
the size of the concrete removal area behind the
column steel, buckling of the column vertical
reinforcing bars can occur. In the majority of
cases, shoring systems will not unload the
compressive stress in the column section.
When new repair material is placed in the
prepared area, the new material cures and most
materials undergo drying shrinkage, which results
in the new material being put into a tensile stress
state. The new material will not carry compressive
loads until the original concrete compresses farther,
forcing the repair material into compression. If
further compression is beyond the capacity ofthe
existing concrete, failurebf the column may
occur. This key concept affects the concrete
preparation process. In normal concrete repair
(other than columns), removal of the concrete
surrounding the corroding reinforcement (also
known as undercutting) is a normal and necessary
process to provide for a long-term durable repair.
To remove concrete around vertical reinforcing
steel in a column (removing concrete inside the
reinforcing bar cage) can cause the remaining
concrete and/or reinforcement in the column to
become overstressed. From a structural point of
view, this condition may not be desirable. If
concrete is to be removed inside the reinforcement
cage, a qualified structural engineer should
determine the impact of the repair on potential
reinforcement buckling and overall structural
capacity of the column. Note that the discussion
in this section is also applicable in concept to
compression zone portions of other structural
members such as beams, slabs, and walls (with
or without compression reinforcement) where
on -going compressive stress exists and where
adequate shoring cannot be installed prior to
rep airs to prevent displacements and corresponding
stress redistributions during repairs.
4M®RIPP
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/COS7RETE REPAI\gl.nj/9 I N STITUTE
11.0 Sammy
The repair of deteriorated concrete resulting from
reinforcing steel corrosion is necessary to extend
the service life of.the structure. Performing
concrete repairs using industry -best practices will
ensure the success and longevity of the repair.
Understanding the existing conditions and cause
of corrosion will assist the engineer in specifying
the type and extent of the repair required, and the
type of corrosion mitigation systems and/or
preventative measures that should be considered
to protect the structure from future deterioration.
1200 References
12.1 Referenced
Standards and Reports
The following standards and reports were the
latest editions at the time this document was
prepared. Because these documents are revised
frequently, the reader is advised to contact the
proper sponsoring group if it is desired to refer
to the latest version.
American Concrete Institute (ACQ
ACI 506R, "Guide to Shotcrete"
ACI E706 (RAP 8), "Installation of Embedded
Galvanic Anodes"
American Society for Testing and
Materials (ASTM International)
ASTMC1583, "Standard Test Method forTensile
Strength of Concrete Surfaces and the Bond
Strength or Tensile Strength of Concrete Repair
and Overlay Materials by Direct Tension (Pull -
off Method)'
International Concrete Repair
Institute (ICRI)
ICRI Concrete Repair Terminology
ICRI Technical Guideline No. 130.1R-2008
(formerly No. 03735), "Guide for Methods of
Measurement and Contract Types for Concrete
Repair Work"
ICRI Technical Guideline No. 210.3-2004
(formerly No. 03739), "Guide for Using In -Situ
Tensile Pull -Off Tests to Evaluate Bond of
Concrete Surface Materials"
GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OFDETERIORATED CONCRETE RESULTING FROM REINFORCING STEEL CORROSION 310.1R-2008-7
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ICRI Technical Guideline No. 310.3-2004
(formerly No. 03737), "Guide for the Preparation
of Concrete Surfaces for Repair Using Hydro -
demolition Methods"
ICRI Technical Guideline No. 320.2R-2008
(formerly No. 03733), "Guide for Selecting and
Specifying Materials for'Repair of Concrete
Surfaces"
These publications may be
obtained from these organizations:
American Concrete Institute
38800 Country Club Drive
Farmington Hills, MI 48331
www.concrete.org
ASTM International
100 Barr Harbor Drive
West Conshohocken, PA 19428
www.astm.org
International Concrete Repair Institute
3166 S. River Road, Suite 132
Des Plaines, IL 60018
www.icri.org
8-310.113-2008 GUIDE FOR SURFACE PREPARATION FOR THE REPAIR OF DETERIORATED CONCRETE RESULTING FROM REINFORCING STEEL CORROSION