Historic Preservation - Technical Procedures
Installing Steel Bar Anchors In Brick Walls With Cementitious Grout
Jacob Weinberger Us Courthouse, San Diego, Ca
Installing Steel Bar Anchors In Brick Walls With Cementitious Grout
INSTALLING STEEL BAR ANCHORS TO REINFORCE UNREINFORCED BRICK WALLS
A. This procedure includes guidance on reinforcing brick
masonry walls by installing anchor bars into core drilled
holes. Such action may be required due to seismic
considerations of a project. This procedure involves the
1. Core drill holes into walls for installation of bar
2. Remove existing brick to form cavities for access
to connect the anchors to the structure of the
3. Provide and install threaded reinforcing bar
anchors in the core drilled holes.
4. Embed the anchors in cementitious grout pumped into
the core drilled holes.
B. See 01100-07-S for general project guidelines to be
reviewed along with this procedure. These guidelines
cover the following sections:
1. Safety Precautions
2. Historic Structures Precautions
4. Quality Assurance
5. Delivery, Storage and Handling
6. Project/Site Conditions
7. Sequencing and Scheduling
8. General Protection (Surface and Surrounding)
These guidelines should be reviewed prior to performing
this procedure and should be followed, when applicable,
along with recommendations from the Regional Historic
Preservation Officer (RHPO).
A. American Society for Testing Materials (ASTM), 100 Barr
Drive, West Conshohocken, PA 19428, (610) 832-9585 or FAX
1. ASTM C 62-85A, "Standard Specification for Building
Brick (Solid Masonry Units made from Clay or
2. ASTM C 67-85, "Standard Methods of Sampling and
Testing Brick and Structural Clay Tile".
B. Occupational Safety and Health Administration (OSHA).
1. "OSHA General Industry Safety and Health Standards
(29 CFR 1910), Publication V2206.
2. "OSHA Construction Industry Standards (29 CFR
3. Both regulations can be found in OSHA Publication
2207, which includes a combination of both Parts
1910 and 1926 as they relate to construction safety
and health. It is for sale by the Superintendent
of Documents, U.S. Government Printing Office,
Washington DC 20402.
A. Product data:
1. Certified copies of mill reports indicating
chemical and physical properties of threaded rebar.
2. Certificates of compliance for Portland cement, fly
ash, lime and sand from an approved independent
B. Quality Control Submittals:
1. Procedures: Submit descriptive data and written
procedures for core drilling of holes and cutting
out of access cavities in existing brick.
2. Submit schedule and description of procedure for
drilling, inserting anchors and injection of grout.
3. Material Quality: Submit reports of tests of the
strengths of the threaded parts of reinforcing bar
assemblies showing compliance with these
procedures. Certified material certificates may be
provided in lieu of test reports when permitted by
the Contracting Officer on the basis of adequate
A. Steel Items:
1. Threaded reinforcing bars shall be deformed bar
conforming to ASTM A615, Grade 60.
2. Threaded reinforcing bars shall have rolled or
forged threads at one end capable of developing the
following yield and tensile strengths:
DIAMETER SIZE YIELD TENSILE
3/4 #6 19,800 Pounds 33,000 Pounds
7/8 #7 27,000 Pounds 46,000 Pounds
1-1/8 #9 45,000 Pounds 76,000 Pounds
3. Nuts shall be hex head, heavy type conforming to
ASTM A307 or as required by specifications of the
manufacturer of the threaded reinforcing bars.
Nuts shall be capable of developing in the bar the
ultimate strength noted on the drawings.
B. Cementitious Materials:
1. Portland Cement: ASTM C150, Type I or Type II low
2. Lime: ASTM C207, Type S.
3. Fly Ash: ASTM C618, Type F.
4. Silica Sand: #30 and #90 Grit
5. Water: Clean and potable (drinkable).
C. Grout Injection Equipment:
1. Mortar pump with agitation hopper that is capable
of producing thirty p.s.i., with a pressure switch
that will stop grout flow at thirty p.s.i.
2. Cement Mixer.
3. Volume measuring containers.
4. 3/4 inch masonry drill bits and rotary drill motor.
5. Power Cord.
6. Water hose.
7. Water hose nozzle that is adjustable to 1/4 inch
8. OSHA approved scaffold and/or ladders.
9. A 5/8 inch injection nozzle capable of penetrating
to the core drilled hole containing the anchor.
The nozzle shall have a device capable of retaining
grout at a pressure of 27-30 p.s.i. At 30 p.s.i.
flow of grout to the tube must automatically be
10. Pressure monitoring system at ground level for use
by the testing laboratory inspector.
11. Plastic foam joint filler for plugging injection
ports to prevent grout flow: preformed
compressible, resilient, foam of diameter
appropriate to prevent flow from injection ports.
A. Grout Proportions and Mixing:
1. Parts shall be measured by volume.
3 parts #30 silica sand
1 part #90 silica sand
1 part Portland Cement
1/2 part lime
1/2 part fly ash
Enough water to sufficiently achieve a consistency
as determined by Section 2.02 A.3. below.
3. Consistency Test:
a. A grout sample shall be taken from the nozzle.
Fill a 2 inch diameter by 4 inch high
b. Pour the sample slowly from 12 inches high
onto an impervious smooth level surface.
c. Proper consistency is indicated by a six inch
to seven inch diameter puddle on the
impervious surface. The diameter shall be
calculated as the average of 2 widths of the
puddle measured at right angles to each other,
one being the maximum width.
4. Grout mixing. Thoroughly mix dry ingredients
before adding water. Mix in quantity that can be
used in 1-1/2 hours after initially adding water to
the dry ingredients. Water may be added to
maintain proper consistency during the allowed 1-
A. Surface Preparation:
1. Equipment: Drilling equipment shall not be
anchored into architectural finishes. Finishes
removed for access or clearance and damaged
finishes shall be replaced to match the adjacent
a. Cavities shall be formed by using non-impact
b. Holes for deep anchors shall be core drilled
to the depths required and locations. Before
drilling, determine the location of
obstructions and the necessary clearances to
prevent damage to embedded pipes, windows, and
c. Roughen anchor holes by rotary wire brush
scouring full length.
d. Clean holes with high pressure air and a nylon
e. Drill injection ports with non-impact rotary
3.02 ERECTION, INSTALLATION, APPLICATION
A. Drill holes for deep anchors. The size of the holes
shall be 3/8" minimum, 5/8" maximum larger than the
nominal bar diameter.
B. Drill injection ports to intersect the deep anchor holes.
Holes that miss the deep anchor holes shall be filled
with injection grout.
C. Flush the hole and ports with water at full city pressure
through a 1/4" nozzle. Start flushing at the high point
of sloping holes, working toward the low; at horizontal
holes, start at the end, working toward the aperture;
flushing each port in sequence until all ports have been
flushed and water flows clean from the hole. Use water
adequate to saturate the brickwork. Use vacuum to
collect water as it emerges; to protect damage to
D. Insert bar anchors. Secure bar anchors in proper
position for connection to the hardware.
E. Inject grout starting at the low point. Continue
injection until grout flows from the next port. Plug the
port and continue injection and plugging of ports until
flow stops at 30 p.s.i. pump pressure or the hole is
filled. If flow stops, immediately begin injecting at
the next open injection port to be plugged and continue
as above. If the port will not take injection,
immediately begin injection at the nearest open port and
continue as above.
F. After hole is filled, remove plugs and fill injection
ports with grout.
G. Wash grout spillage from wall immediately. Remove and
dispose of all spilled grout.
END OF SECTION