Tips for optimizing structural masonry

TIPS TO OPTIMIZE
STRUCTURAL MASONRY
presented by
International Masonry Institute

INTERNATIONAL MASONRY INSTITUTE
APPRENTICESHIP
& TRAINING
MARKET DEVELOPMENT
& TECHNICAL SERVICE

ILLINOIS STRUCTURAL MASONRY COALTION

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© International Masonry Institute 2010
Copyright Materials
This presentation is intended for the use of industry professionals who are
competent to evaluate the significance and limitations of the information provided
herein. This publication should not be used as the sole guide for masonry design
and construction, and IMI disclaims any and all legal responsibility for the
consequences of applying the information.

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method or manner of handling, using, distributing or dealing in
any material or product. Questions related to specific materials,
methods and services will be addressed at the conclusion of
this presentation.

Learning Objectives
• Understand interrelationship
between masonry materials,
architecture, engineering,
and construction.
• Learn how a few simple
decisions can lead to more
efficient and economical
structures.
• Discover some non-
traditional structural
masonry materials and
systems.
• Apply code, specification
and standards provisions
appropriately.

Using masonry for the
building’s structural support
– Bearing walls
– Shear walls
– Combination bearing & shear
– Hybrid!
– Partition walls (not structural)

Theater at Ostia Antica, Rome
c. 200 AD

 Versatile structural system
 Fast, efficient & economical
 Masonry may be on the project already –
use it structurally!

 Finish trade – so tighter tolerances are held
 No lead time for production, review and
approval of shop drawings
 Adapts easily to field changes –
“with masonry you just pick up the phone and
the change can be done”

 Local materials, local employment
 Using material efficiently – one
material for structure, finish, fire
resistance, blast resistance, acoustics
and more…
 Masonry is “Green”
 And it looks good too!

Get started right…
 MSJC Documents
 Building Code Requirements for Masonry
Structures TMS 402-08 / ACI 530-08 / ASCE
5-08
 Specification for Masonry Structures
TMS 602-08 / ACI 530.1-08 / ASCE 6-08
 International Building Code 2009
 ASTM Masonry Standards
 More than 75 under the masonry
committees jurisdiction
 Another 15 new ones under development
 Narrow down to a few basic ones

Materials
Concrete Masonry Units

Tip 2 – Use the right ASTM Standard
 ASTM C 90 Standard Specification for Loadbearing
Concrete Masonry Units
 Use for projects requiring loadbearing CMU
 Sets minimum requirements
 Include the edition
 Example: ASTM C 90-09
 Defaults to version referenced by local building code if
not specified

Tip 3 – Unit Compressive Strength & Density
 ASTM C 90-09 Table 2
 Compressive strength requirements are independent of
unit density
Example: Lightweight units are required to meet the same
compressive strength minimum requirements as Medium
weight and Normal weight units

Tip 4 – Remember, Minimum Requirements
 ASTM C 90-09
 Minimum compressive strength requirements in Table 2
 No maximum compressive strength limit
 Permissible to specify higher unit strength which leads to
higher compressive strength for the masonry wall
 Check local availability before specifying higher
strength units

Tip 5 – Specify Above C90 Minimum Strength
 If higher strength units are available, the effect on the
structural design can be significant
 Often very little, if any cost penalty for units with
strengths above the ASTM C 90 minimum
 May already be on the job – so use what you already
have!
for example…

Tip 5 – Specify above C90 Minimum Strength
Checking the test report

Tip 5 – Specify Above C90 Minimum Strength
Finding the average unit compressive strength

Tip 5 – Specify Above C 90 Minimum Strength
Unit Strength Method to determine Masonry Compressive Strength
3067
ASTM C90
Minimum unit
strength
Average unit
compressive
strength from
testing report
2140

Tip 5 – Specify Above C 90 Minimum Strength

Masonry Compressive Strength Options
 Increase the compressive strength of masonry
 Check actual compressive strength of the units
 Specify higher compressive strength units
 Consider prism testing on larger projects
 Consider larger width units if necessary

© 2009 INTERNATIONAL MASONRY INSTITUTE
ELEVATIONS
DIAGRAM 01.410.0311 REV. 08/10/09
MORTAR JOINT MATERIAL TAKEOFF
UTILITY BRICK, RUNNING BONDMODULAR BRICK, RUNNING BOND
4 @ 12” x 3/8” = 18.000 SQ. IN.BED JOINTS
HEAD JOINTS 8 @ 2.3125” x 3/8” = 6.938 SQ. IN.
2 @ 1.3125” x 3/8” = 0.984 SQ. IN.
25.922 SQ. IN. MORTAR
3 @ 12” x 3/8” = 13.500 SQ. IN.
3 @ 3.625” x 3/8” = 4.078 SQ. IN.
17.578 SQ. IN. MORTAR
18.00% MORTAR 12.21% MORTAR
ONE SQUARE FOOT ONE SQUARE FOOT
18% 12%

ASTM C 270
Mortar Options:
- Portland Cement and Lime
- Masonry Cement
- Mortar Cement
Mortar Types: M, S, N,
and O
Mortar Quality Control
ASTM C 270 MASONRY MORTARS
MORTAR

M S N O Krwoa
ASTM C 270 MASONRY MORTARS
MORTAR

ASTM C 270 TABLE 1 – PROPORTION SPECIFICATION
MORTAR

ASTM C 270 TABLE 2 – PROPERTY SPECIFICATION
MORTAR

M S N O K
general ratio
cement : lime : sand
1:½:4½ 1:1:6 1:2:9 1:3:121:¼:3¾
Refer to ASTM C 270 for acceptable ranges
PROPORTION RULES-OF-THUMB
MORTAR

Preblended grout mixed from dry ingredients in silo
PREBLENDED MORTAR & GROUT

STANDARD SPECIFICATION FOR
GROUT FOR MASONRY
ASTM C476-10

Grout is NOT mortar NOR
concrete and is a cementitious
material unique to masonry.
• Grout can be mixed on-site or
obtained from transit or Redi-mix
suppliers.
• Grout can be placed by hand
or pumped with specifically
designed grout pumps.
• Grout quantities can be
determined from reference
charts such as the one shown on
the next slide.
GROUT

6”
Thick Walls
All Cells Filled
16” o.c.
24” o.c.
32” o.c.
40” o.c.
48” o.c.
0.93
0.55
0.42
0.35
0.31
0.28
0.83
0.49
0.37
0.31
0.28
0.25
120
205
270
320
360
396
8”
Thick Walls
All Cells Filled
16” o.c.
24” o.c.
32” o.c.
40” o.c.
48” o.c.
1.12
0.65
0.50
0.43
0.37
0.34
1.00
0.58
0.44
0.38
0.33
0.30
100
171
225
267
300
330
10”
Thick Walls
All Cells Filled
16” o.c.
24” o.c.
32” o.c.
40” o.c.
48” o.c.
1.38
0.82
0.63
0.53
0.47
0.43
1.23
0.73
0.56
0.47
0.42
0.38
80
137
180
214
240
264
12”
Thick Walls
All Cells Filled
16” o.c.
24” o.c.
32” o.c.
40” o.c.
48” o.c.
1.73
1.01
0.76
0.64
0.57
0.53
1.54
0.90
0.68
0.57
0.51
0.47
65
111
146
174
195
215
Standard
Two Cell
Block
Grouted Cells
Vertical Steel
Spacing
Cu. Yds. Of
Grout Per 100
Sq. Ft. of Wall
Cu. Yds. Per
100 Block
(8”h X 16”w)
Block Per Cu.
Yd.
(8”h X 16”w)

FINE & COARSE GROUT
Grout Specimen
Fine Aggregate
Grout Specimen
Coarse Aggregate

Conventional Grout
SCOPEASTM C476-10
SCG

3. Materials
3.1.1 Cementitious Materials
3.1.1.1 Portland Cement
3.1.1.2 Blended Cements
3.1.1.3 Quicklime
3.1.1.4 Hydrated Lime
3.1.1.5 Coal Fly Ash or Raw Calcined
Natural Pozzolan
3.1.1.6 Granulated Blast Furnace Slag
3.1.2 Air Entraining Admixtures
3.1.3 Aggregates
3.1.4 Water
3.1.5 Admixtures
3.1.5.1 Admixtures for SCG
3.1.6 Pumping Aids
3.1.7 Antifreeze Compounds
3.1.8 Storage of Materials
MATERIALS
Clean & potable
iwr, accelerators, etc.
Not permitted
Protect from moisture
ASTM C476-10
water-reducers, viscocity modifiers

GROUT TYPE & PROPORTIONS
4. Grout Type and Proportions
4.1 Type
4.1.1 Fine grout
4.1.2 Coarse grout
4.2 Proportions of Ingredients
4.2.1 Conventional Grout
4.2.1.1 Table 1
4.2.1.2 Specified Compressive Strength
4.2.2 Self-consolidating Grout
4.2.2.1 Specified Compressive Strength
2,000 psi at 28 days
Per astm c1019
Fine aggregate
Coarse and Fine aggregates
24-30 in. slump flow;
2,000 psi at 28 days
Per astm c1019
Vsi < 1
ASTM C476-10

• Coarse grout is typically more economical than fine grout
and is usually preferred.
• Both coarse and fine grout can be designed to achieve
necessary strength requirements.
• Space consumed by mortar fins must be subtracted from
the clear space.
• Minimum clear cross-sectional dimensions of the cells to
be grouted are shown in the chart on the next slide.
FINE GROUT vs. COARSE GROUT

Table 3.1.2-Grout space requirements *
Grout type1
Maximum grout
pour height,
Ft.
Minimum width
of grout space,
In.
Minimum grout
space
dimensions for
grouting cells of
hollow unit
in. x in.
Fine
Fine
Fine
Fine
1
5
12
24
3/4
2
21/2
3
1 ½ x 2
2 x 3
2 ½ x 3
3 x 3
Coarse
Coarse
Coarse
Coarse
1
5
12
24
1 ½
2
2 ½
3
1 ½ x 3
2 ½ x 3
3 x 3
3 x 4
* MSJC Code
FINE GROUT vs. COARSE GROUT

1/2” MAX.
MORTAR FIN
MORTAR PROTRUSION TOLERANCE
DIAGRAM 02.410.0121 REV. 02/22/09
MORTAR FINS

Mortar Fins (protrusions)
Mortar fins restrict the flow of grout
into cells and can actually trap air.
They must be removed before
grouting takes place. The best time
to do this is during wall construction.
MORTAR FINS

MASONRY PRISM
Masonry Prism
Sectioned prism, (2) CMU,
Mortar Joint, Grout, Rebar

However, remaining fins should be broken free
and dropped to the cleanouts and removed before
grouting takes place.
Proper technique in the application of mortar and
the setting of the CMU should minimize mortar
fins.
MORTAR FINS

Grout should be able to flow completely
around the rebar.
Clearance must be provided between the:
• Face shells of the CMU
• Other rebar
Masonry & grout coverage also protects
the rebar from corrosion or weather.
MINIMUM MASONRY COVER

1 1/2 inch minimum cover for interior face.
2 inch minimum cover for exterior
face exposed to earth or weather
MINIMUM MASONRY COVER
.

1/2” MIN. FOR COURSE GROUT
1/4” MIN. FOR FINE GROUT
MINIMUM DISTANCE FROM ANY
PROTRUSION:
REINFORCEMENT PLACEMENT TOLERANCE
DIAGRAM 02.410.0123 REV. 02/22/09
MINIMUM GROUT CLEARANCE

MSJC 2008 Specification for Masonry Structures
 “Grout compressive strength equals or exceeds f’m but not less than 2000 psi.”
(Article 1.4 B.2.a.3)b) and 1.4 B.2.b.3)b))
 “Grout compressive strength equals or exceeds f’aac but compressive strength is
not less than 2000 psi.” (Article 1.4 B.c.3)b))
 “unless otherwise required, provide grout that conforms to the requirements of
ASTM C 476, or ” (Article 2.2 A.1)
 “…attains the specified compressive strength or 2000 psi, whichever is greater,
at 28 days when tested…” (for self-consolidating grout) (Article 2.2 A).2)
ASTM C 476-10 Standard Specification for Grout for Masonry
 “…and shall have a minimum compressive strength of 2000 psi at 28
days.”
(Section 4.2.1.1 (Conventional grout))
 …”The grout shall have a minimum compressive strength of 2000 psi at
28 days.” (Section 4.2.2.1 (Self-consolidating grout))
GROUT TYPE & PROPORTIONSASTM C476-10

STANDARD TEST METHOD FOR
SAMPLING AND TESTING GROUT
ASTM C1019-09

SCOPE; SIGNIFICANCE & USEASTM C1019-09
1. Scope
1.1 This test method covers
procedures for both field and
laboratory sampling and
compression testing of grout used
in masonry construction.
3. Significance & Use
3.1 Grout used in masonry is a fluid
mixture of cementitious materials
and aggregate with a high water
content for ease of placement.
3.1.1 During construction,
grout is placed within or
between absorptive masonry
units. Excess water must be
removed from the grout
specimens in order to provide
compressive strength test
results more nearly indicative of
the grout strength in the wall.

TEST SPECIMENSASTM C1019-09
PROCEDURES
5. Test Specimens
5.1 Each grout specimen shall
have a square cross section,
3 in. or larger on the sides and
twice as high as its width.
5.2 Test at least three specimens
at each age specified.
Note 4: frequency of sampling and
age of test is to be determined by
the specifier, and is usually found
in the construction documents; for
example, one set of specimens may
be specified for every 5,000 s.f. of
wall.
EXAMPLE: IF SPECIMENS ARE TO BE
TESTED AT 7, 14, AND 28 DAYS, THEN
MAKE 9 SPECIMENS.

GROUT SPECIMEN MOLDSASTM C1019-09

SCOPEASTM C1019-09
6. Grout Specimen Molds
6.1 Molds from Masonry Units
6.1.1 Select a level location where the molds
remain undisturbed for up to 48 hours.
6.1.2 The construction of the mold shall simulate the
in-situ construction. If the grout is
placed between two different types of
masonry units, both types shall be used to
construct the mold.
6.1.3 Form a space with a square cross-section,
3 in. or larger on each side and twice as high
as its width, by stacking masonry units of the
same type and moisture condition as
those being used in the construction. The
surface of the unit in contact with the grout
specimen shall not have been previously
used to mold specimens. Place non-
absorbent block, cut to proper size and of the
proper thickness or quantity, at the bottom of
the space to achieve the necessary height of
specimen.
5% tolerance on dims.

Filling Slump Cone
Hold cone firmly
in position so grout
does not escape
while filling the cone.
Slump cones are for testing grout
consistency prior to grouting.
SLUMP TEST, CONVENTIONAL GROUT

1/3
Fill the bottom 1/3
and rod 25 times
with the puddle rod.
Straight in and
Straight out… do not
stir.
Filling Slump Cone

2/3
Fill the middle 1/3
and rod 25 times.
Penetrate bottom
1/3 only slightly.
Filling Slump Cone

3/3
Fill the top 1/3
and rod 25 times.
Penetrate middle
1/3 only slightly.
Filling Slump Cone

Grout should slump
8 to 11 inches.
Lift the cone slowly
and straight up.
Do not twist or turn.
Remove Slump Cone

Conventional Grout
ASTM C 143
8 - 11” slump
SCG
ASTM C1611
24” to 30” slump flow
VSI < 1
SLUMP vs. SLUMP FLOW

ALTERNATIVE METHODSASTM C1019-09
6. Grout Specimen Molds
6.2 Alternative Methods - … used
only with approval of the
specifier.
Note 7: fill compartments in
slotted corrugated cardboard
boxes specifically manufactured
to provide grout specimens.

CALCULATIONSASTM C1019-09
11. Calculations
11.1 Determine the average cross-
sectional area by measuring the
width of each face at its mid-height,
calculating the average width of
opposite faces, and multiplying the
averages.
11.2 For specimens from molds of
masonry units, calculate the
compressive strength by dividing
the maximum load by the average
cross-sectional area and express
the result to the nearest 10 psi. x2
x1
y1
y2
P
Average cross-sectional Area =
x1 + x2
2 2
y1 + y2.

Tip 10 – Understand Grout Pours and Lifts
Often confused or used interchangeably. MSJC Definitions:
 Grout Pour – The total height of masonry to be grouted prior to erection of
additional masonry. A grout pour consists of one or more grout lifts.
 Grout lift – An increment of grout height within a total grout pour. A grout
pour consists of one or more grout lifts.
Maximum pour height – function of grout type (fine or coarse), minimum grout
space dimensions, use of cleanouts, conventional grout or SCG. Maximum
pour heights are established by MSJC Table 7.
Maximum lift height – default is 5’, may increase to 12’-8” under some
circumstances. SCG may be increased to pour height under some
circumstances.

1999 MSJC – 5’ lift height limitation.
2002 MSJC – demonstration panel option permitting
any construction procedures that produce proper
installation.
2005 MSJC – lift height increased to 12’-8” subject
to conditions.
2008 MSJC – Self-consolidating grout provisions

Grout lift height –
A.) Where the following conditions are met, place grout in lifts not
exceeding 12.67ft
1.The masonry has cured for at least 4 hours.
2. The grout slump is maintained between 10 and 11 in.
3. No intermediate reinforced bond beams are placed
between the top and the bottom of the pour height.
B.) As above but intermediate bond beam, then lift height can extend
to the bottom of the bond beam but not to exceed 12.67’.
C.) Otherwise, place grout in lifts not exceeding 5ft.
D.) Demonstration panel option may result in increases.
E.) SCG may, under some circumstances be permitted to have the
grout lift equal the pour height.

Self Consolidating Grout Demonstration

LOW LIFT GROUTING PROCEDURES
DETAIL 02.410.0131 REV. 06/30/10
VERTICAL REINFORCEMENT FOR
CLOSED-END CONCRETE MASONRY
UNITS CAN BE SET AFTER WALL HAS
BEEN LAID.
REBAR POSITIONER, WALL TIE,
OR OTHER DEVICE TO POSTION
VERTICAL REINFORCEMENT
HORIZONTAL
REINFORCEMENT
PLACED IN BOND
BEAMS AS WALL IS
LAID UP
METAL LATH, MESH, OR WIRE SCREEN
PLACED IN MORTAR JOINTS UNDER KNOCK-
OUT BOND BEAM COURSES TO PREVENT
FILLING OF UNGROUTED CELLS
OPTION 2: STANDARD CMU W/
CROSS WEBS KNOCKED OUT
AT BOND BEAM COURSE
OPTION 1: U-BLOCK
UNITS W/ SOLID
BOTTOM AT BOND
BEAM COURSE
GROUT IN BOND BEAMS & REINFORCED
VERTICAL CELLS PLACED IN TOP OF WALL
AFTER WALL HAS BEEN LAID UP
STOP GROUT 1” FROM TOP OF
POUR TO CREATE SHEAR KEY
CELLS CONTAINING
REINFORCEMENT ARE
FILLED SOLIDLY W/ GROUT;
VERTICAL CELLS SHOULD
PROVIDE A CONTINUOUS
CAVITY FREE OF MORTAR
DROPPINGS
NOTE: GROUT PLACED IN
POURS & LIFTS NOT TO
EXCEED 5 FT. CONSOLIDATE
LIFTS OVER 12” USING MECH.
VIBRATION. LIFTS LESS THAN
12” MAY BE PUDDLED.

HIGH LIFT GROUTING PROCEDURES
DIAGRAM 02.410.0131 REV. 07/06/10
VERTICAL REINFORCEMENT FOR
CLOSED-END CONCRETE MASONRY
UNITS CAN BE SET AFTER WALL HAS
BEEN LAID.
REBAR POSITIONER, WALL TIE,
OR OTHER DEVICE TO POSTION
HORIZONTAL
REINFORCEMENT
PLACED IN BOND
BEAMS AS WALL IS
LAID UP
PLACED IN MORTAR JOINTS UNDER KNOCK-
OUT BOND BEAM COURSES TO PREVENT
FILLING OF UNGROUTED CELLS
OPTION 2: STANDARD CMU W/
CROSS WEBS KNOCKED OUT
AT BOND BEAM COURSE
OPTION 1: U-BLOCK
UNITS W/ SOLID
BOTTOM AT BOND
BEAM COURSE
GROUT IN BOND BEAMS & REINFORCED
VERTICAL CELLS PLACED IN TOP OF WALL
AFTER WALL HAS BEEN LAID UP
STOP GROUT 1” FROM TOP OF
POUR TO CREATE SHEAR KEY
CELLS CONTAINING
REINFORCEMENT ARE
FILLED SOLIDLY W/ GROUT;
VERTICAL CELLS SHOULD
PROVIDE A CONTINUOUS
CAVITY FREE OF MORTAR
DROPPINGS
NOTE: GROUT LIFTS
NOT TO EXCEED 5 FT.
SEE STRUCTURAL
DWGS FOR MAX.
HEIGHT OF POUR.
MECH. CONSOLIDATE &
RECONSOLIDATE
GROUT
CLEANOUT OPENINGS @ BASE OF
VERTICALLY REINF. CELLS, 32” O.C.
MAX. SPACING FOR SOLID GROUTED
WALLS. REMOVE MORTAR
DROPPINGS THROUGH CLEANOUTS
AND VERIFY PLACEMENT & LOCATION
OF VERTICAL REINF.; FORM OVER
OPEN’GS BEFORE PLACING GROUT

Tip – Consider Cleanout options
 Multiple options for cleanout construction
 Does not have to be a full face shell high
 Minimum size is 3”
 Can be concealed easily on interior walls with base
molding
Cleanout

BRACE CLEANOUT
AND PLACE GROUT
CUT PORTION OF
FACE SHELL TO
CREATE CLEANOUT
REINSERT FACE
SHELL AND
MORTAR IN PLACE
PLACE REINFORCING
AND INSPECT WALL
FOR OBSTRUCTIONS
REMOVE
BRACING
BLOCK CLEANOUT
DIAGRAM 02.410.0111 REV. 06/12/09

CUT FACE SHELL
FOR CLEANOUT
WOOD BRACING
GROUT &
REINFORCEMENT
BLOCK CLEANOUT
DIAGRAM 02.410.0112 REV. 06/12/09

REINSERT FACE SHELL
PIECE TO RESIST
GROUT PRESSURE
CUT WEDGE-SHAPED
PORTION OF FACE SHELL
TO CREATE CLEANOUT
CLEANOUT
MORTAR FACE SHELL
EDGES IF NECESSARY
BLOCK CLEANOUT
DIAGRAM 02.410.013 REV. 06/12/09

1. CUT OUT
PORTION OF FACE
SHELL
2. PLACE ACRYLIC
GROUT STOP
INTEGRALLY BRACED
AGAINST INSIDE OF
FACE SHELL
3. HAND-TIGHTEN
BRACE
5. REMOVE ACRYLIC
AND BREAK OFF
PLASTIC BRACE
4. PLACE REBAR
& GROUT
BLOCK CLEANOUT
DIAGRAM 02.410.0114 REV. 06/12/09

Tip 11 – Give the Contractor Some Latitude
Give the contractor some latitude in the….
 Selection of Fine or Coarse Grout
 Technical considerations
 Grout space dimensions
 Pour height limitations
 Compressive strength independent of type
 Constructability considerations
 Ease of use/Personal preference
 Cost implications – material, placement
 Issues related to pour height (next slide)
Fine Grout might
be better suited
here
Coarse or Fine Grout
here

 Determination of Pour and Lift height
 Code/Spec compliance
 Inspection options
 Other
 Cleanouts
 Bracing
 Site constraints
 Coordination of trades
 Placement procedures
 Other

 Use of self-consolidating grout
 New material comfort level
 Grout spaces and pour heights
 Inspection and testing capabilities
 Local supplier experience
 More
 Cost
 Availability
 Experience with the product
 Grout space/height
• More

AS REQ’D
GROUT AS REQ’D
HORIZONTAL JOINT
REINFORCEMENT
CMU SHOWN IN
LONGITUDINAL
SECTION
DOWELS MAY BE BENT
UP TO 1” LATERALLY
PER 6” VERTICALLY
FOUNDATION
FOUNDATION DOWEL ALIGNMENT
DETAIL 02.010.0301 REV. 02/22/09

SPACING OF VERTICAL REINFORCEMENT
±1/2” IF d ≤ 8”
d
±1” IF 8”< d ≤ 24”
±1¼” IF d > 24”
±2”
REINFORCEMENT PLACEMENT TOLERANCE
DIAGRAM 02.410.0122 REV. 02/24/09

Innovations
Spanning the Opening

SPANNING OPENINGS
DOUBLE ANGLES AT BLOCK

SPANNING OPENINGS
Massive steel sections can be expensive and inefficient
STEEL BEAM and PLATE

SPANNING OPENINGS
CONCRETE MASONRY LINTEL

SPANNING OPENINGS
Poly-wrapped steel angles used for temporary support
CAST-IN-PLACE MASONRY LINTEL © 2009 INTERNATIONAL MASONRY INSTITUTE

SPANNING OPENINGS
Precast masonry lintel fabricated on the ground
PRECAST LINTELS © 2009 INTERNATIONAL MASONRY INSTITUTE

SPANNING OPENINGS
Lintel is hoisted by lift
PRECAST LINTELS © 2009 INTERNATIONAL MASONRY INSTITUTE

SPANNING OPENINGS
Precast lintel set into place
PRECAST LINTELS

SPANNING OPENINGS
10-foot span
PRECAST LINTELS

U-BLOCK CMU BOND BEAMS
DIAGRAM 02.410.0142 REV. 07/08/10
CMU BOND BEAM MADE
FROM U-BLOCK UNITS
VERTICAL
REINFORCEMENT
AS REQ’D
HORIZONTAL
REINFORCEMENT
AS REQ’D
U-BLOCK NOTCHED
TO ACCEPT VERTICAL
REINFORCEMENT
SPECIAL SHAPE
U-BLOCK

KNOCK-OUT CMU BOND BEAMS
DIAGRAM 02.410.0141 REV. 07/08/10
VIEW OF STANDARD
BLOCK BEFORE
CROSS WEBS ARE
KNOCKED OUT
VIEW OF BLOCK AFTER CROSS
WEBS ARE KNOCKED OUT TO
ACCOMMODATE HORIZONTAL
REINFORCEMENT
PLACED IN BED JOINTS UNDER KNOCK-OUT
BOND BEAM COURSES TO PREVENT FILLING
OF UNGROUTED CELLS
VERTICAL
REINFORCEMENT
AS REQ’D
HORIZONTAL
REINFORCEMENT
AS REQ’D

Structural Options & Efficiencies
 Use masonry as
 Lintels
 Deep beams

VIEW OF INTERSECTING
BOND BEAMS PRIOR TO
GROUT PLACEMENT
LENGTH AS REQUIRED TO
DEVELOP REINFORCEMENT
GROUT AND
REINFORCING
AS REQ’D
KNOCK OUT FACE
SHELL OF BOND
BEAM UNIT FOR
CONT. GROUT &
REINFORCEMENT
NOTE: SEE BUILDING CODE
REQUIREMENTS FOR
REINFORCEMENT
DEVELOPMENT LENGTHS
AND MINIMUM AREA OF
REINFORCEMENT REQ’D
RAKE OUT
MORTAR FOR
CONTROL JOINT
FLANGE
WALL
WEB WALL
RAKE OUT
MORTAR FOR
VERTICAL C.J.
INTERSECTING WALLS
DETAIL 02.120.1523 REV. 02/22/08
BOND BEAMS

FLANGE WALL
WEB WALL
CONTROL JOINT
50% INTERLOCKING
UNITS REQ’D TO
BOND WALLS
CONTROL JOINT
GROUT AND REINFORCING
AS REQ’D
INTERSECTING WALLS
DETAIL 02.120.1521 REV. 02/22/08
50% INTERLOCKING UNITS

RAKE OUT
MORTAR AND
CAULK
GROUT STOP
WEB WALL
FLANGE WALL
MIN. 24” L x 1½” W x ¼”
THICK Z-STRAP
CONNECTOR W/ 2”
EXTENSIONS EA. END
STEEL
CONNECTOR
CONNECTOR EMBEDDED
INTO GROUT-FILLED CORES
@ EACH END
GROUT AND REINFORCING
AS REQ’D
INTERSECTING WALLS
DETAIL 02.120.1522 REV. 02/22/08
STEEL CONNECTOR

Options, options and more options!
Hybrid masonry/steel frame
 Reinforced Masonry infill
 Combined with structural steel
frame
 Masonry acts as bracing
 Eliminates cutting infill around
steel cross bracing

c) TYPE I HYBRID
∆= 0.02” (0.5 mm)
a) RIGID FRAME
10 KIPS
W12x35
∆
W12x40
∆= 4” (100 mm)
W8x24
W8x15
W8x15
10 KIPS
b) BRACED FRAME
∆= 0.04” (1 mm)
W8x15
W8x24
10 KIPS
W12x40
W8x15
Note detailing issues due
to frame deflection
CMU cuts around brace
not shown

GAPS 1, 2: NO IN-PLANE LOAD TRANSFER
GAP 2GAP 1
GAP 3
TYPE I
BEAM OR
GIRDER
COLUMN
SHEAR WALL
SHEAR (IN-PLANE)
GAP 3: TRANSFERS IN-PLANE SHEAR LOAD; NO AXIAL LOAD
COLUMN

GAPS 1, 2: NO IN-PLANE LOAD TRANSFER (SOFT JOINTS)
GAP 2GAP 1
NO GAP
TYPE II
BEAM OR
GIRDER
COLUMN
SHEAR WALL
SHEAR (IN-PLANE)
BEAM/GIRDER TRANSFERS IN-PLANE SHEAR LOAD
COLUMN
AXIAL LOAD

NO GAPNO GAP
NO GAP
TYPE III
BEAM OR
GIRDER
COLUMN
SHEAR WALL
SHEAR (IN-PLANE)
COLUMN
SHEAR
(IN-PLANE)
SHEAR
(IN-PLANE)
AXIAL LOAD
not yet included in building codes

HYBRID MASONRY & STEEL
Garden Hills Elementary School, Champaign, IL BLDD Architects

Tip 14 – Consider Structural Brick
 Reinforced hollow brick masonry
 Reinforced structural veneer

Innovations
Loadbearing CMU
Pilasters & Columns

SPECIAL SHAPE
PILASTER BLOCK
CMU PILASTER W/ GROUT
& REINFORCEMENT PER
STRUCTURAL ENGINEER
REBAR POSITIONER
GROUTED CELLS PER
STRUCTURAL ENGINEER
LOAD BEARING PILASTER
DETAIL 02.010.1101 REV. 06/17/08

Innovations
Loadbearing AAC Masonry

AAC Craftworker Certification Training

 Design provisions in Appendix A of MSJC
 Strength Design provisions similar to MSJC Chapter 3
 MSJC Specification contains construction provisions
 IBC force resisting system limited to SDC A, B, C
 IRC not limited
 Locally adopted code may differ
Tip 15 – Consider AAC Masonry

8x8x16 normal
weight block
(140 pcf)
8x8x16 light
weight block
(105 pcf)
38 lbs 28 lbs
8x8x16 AAC
AC-4 block
(31 pcf)
18 lbs
UNIT WEIGHT COMPARISONS

14,000 s.f. addition
8” loadbearing AAC
wall
12” loadbearing AAC
wall

8”-12” T. x 8” H. x 24” L. AAC block have
one 4”Ø core to accept a #6 bar @ 24”
o.c.

LOADBEARING AAC MASONRY WALL
DETAIL 13.120.0101 REV. 04/23/10
12” THICK x 8” H. x 24” L.
AC-4 AUTOCLAVED
AERATED CONCRETE
(AAC) MASONRY UNITS
JOIST GIRDERS @ 5’-0”
O.C. PER STRUCTURAL
#6 VERTICAL REINFORCING &
GROUT IN 4”Ø CORES @ 24” O.C.
16” H. BOND BEAM W/ (2) #5
REBAR @ EA. COURSE
NOTE: THIS DRAWING
REPRESENTS A BASIC
STRUCTURAL AAC MASONRY
WALL; IT IS NOT INTENDED FOR
CONSTRUCTION WITHOUT
PROPER ENGINEERING DESIGN
AND CALCULATIONS.

Reinforcement Splices
& Options

Tip 16 – Include Splice Lengths in
Project Documents
Question: Why should the splice lengths and locations be included on
the project drawings?
Answer: The design professional has the information necessary to
calculate lap lengths, the contractor does not. Contractors cannot
be expected to know which lap length equation is applicable nor
the variables that are included in some lap splice equations.
Consider that laps may vary based on:
Bar diameter
Design method (ASD or SD)
Locally adopted building code
Specified cover
Specified f’m
and more…

PLANK AT BEARING WALL
DETAIL 02.120.0751 REV. 11/25/08
INTERMEDIATE ELEVATION
2’-0 HORIZ. x 2’-0”
VERT. #4 DOWELS
AND GROUT AT
PLANK KEYWAYS –
SEE DETAIL 20.P02
3” MIN. BEARING &
BEARING STRIP
BOND BEAM W/
(2) #5, CONT, OR
AS REQ’D
GROUT PLANK
SOLID AT BEARING
GROUT & VERTICAL
REINFORCING AS
REQUIRED
SOLID CMU
PRECAST CONCRETE
PLANK
NOTE: VENEER & AIR/
MOISTURE BARRIER
NOT SHOWN
HORIZONTAL. JOINT
REINFORCEMENT
TOPPING IF REQ’D
LAP VERTICAL BAR
SPLICE ABOVE
PLANK LEVEL

#6 vertical bars in wall required 48 bar dia. lap length = 36 in.
SPLICE LENGTHS

 Options to avoid long lap lengths:
 Use smaller diameter bars at closer spacing.
 Cover distance is key – maximize cover for minimum lap
lengths.
 Minimize laps by permitting higher grout lifts
 Use specified f’m, not just minimum value…
MSJC Equations & IBC SD requirements
Lap length INCREASES as:
•Bar size increases,
•Cover decreases
Lap length DECREASES as:
•Bar size decreases,
•Cover increases,
•Masonry compressive strength increases
Tip 17 – Reduce Splice Length when Appropriate

Question: Which of the above is the better choice?
Answer: Either one could be fine, so consider:
• Bar weight
• Quantity of grout and difficulty in placement
• Are lap splices being used (longer for the #6 bar)
• Generally smaller bars closer together produce more
cohesive behavior for the wall as a whole.
• But, too close together and more grout is needed.
• Is the wall going to be fully grouted for other reasons?
Tip 17 – Reduce Splice Length when Appropriate
Balance bar size & spacing to optimize the design, example:
#4 bar @ 24”c/c is equivalent to #6 bar @ 48”c/c

32” spacing Various spacing
24” spacing
REINFORCEMENT SPACING

 Lap splices
 Mechanical splices
 Becoming more common
 Develop 125% of specified bar
yield strength.
 Welded splices
 Specify weldable reinforcement
 Bars butted and must develop
125% specified bar yield strength.
 Difficult, expensive, not recommended
for most applications
Tip 18 – Consider other Splicing Options

Tip 19 – Think joint reinforcement
not bond beams…
 Joint reinforcement may be
used to meet horizontal
reinforcement requirements
 Bond beams are more expensive
option but may offer more
steel reinforcement area
 For crack control, joint
reinforcement may not be
needed with bond beams
 Can use both in the building to
suit different needs

Options, options and more options!
Prefabricated masonry

And even more….
Software for structural analysis

Structural masonry…
Economical

Masonry as structure
and finish

Sustainable

Fire & Blast Resistant

Think structural masonry for your next project

BAC CONTRACTORS
IMI-TRAINED CRAFTWORKERS
International Union
of Bricklayers and
Allied Craftworkers
International
Masonry
Institute

Tips for optimizing structural masonry

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