1. Design Aides for Concrete Masonry Members
EPSCoR Research Fellowship
Angela Jones
Jennifer Tanner, PhD
University of Wyoming

2. Origin of Masonry Old building material Random rubble masonry

3. Brick Brick making is estimated to be 10,000 to 12,000 years old.

4. Fired Brick

5. Grouted Brick Masonry Bearing wall construction
Large scale use seen in
The late 1800s
Monadnock Building,
Chicago

6. Concrete Masonry Units
Process of constructing CMU began in 1882.
First CMU
Cast were
30” units cast
on site.

7. Concrete Masonry Units
Mechanical Vibration
Zero slump concrete
Current production process highly automated

8. Design Provisions Uniform Building Code BOCA National Building Code
(Building Officials and
Code Administrators International)
The Standard Building

9. International Building Code
Emerged in 1994
Phase out previous codes
By 2000
Broad-based principles

10. Masonry Code Masonry Standards Joint Committee Code
Final review of the first
edition approved in 1988.
MSJC Code is revised
on a three year cycle.

11. Goals Evaluate peak stress conditions Allowable Stress Design
Strength Design

12. Allowable Stress Design
Older analysis
Widely used
Elastic Behavior
External Loads

13. Strength Design Newer analysis ACI 530 code (2002) More complex
Variability in materials

14. Strength Design
Newer analysis
Limit states

15. Strength Design Newer analysis Probability of failure
Statistical Analysis

16. Analysis Interaction Diagrams Single Wythe Masonry Walls
#4, #5, #6 Reinforcement
6”, 8”, 10”, and 12” walls
12” and 24” reinforcement spacing
Solid and Partially Grouted Walls

17. Analysis Interaction Diagrams Axial Capacity Flexural Capacity
Balance Point
Tension Controlled
Compression Controlled
Flexural Capacity
Column Analysis
T-Beam Analysis
I-Beam Analysis

18. Simple Analysis effective width, bf Fb C hf kd bw h T = As*fs
Steel Reinforcement
0 < kd < 1.25”
Allowable Stress Design

19. T-Beam Analysis effective width, bf Fb F1 F2 hf kd F3 bw h
Steel Reinforcement
1.25” < kd < h-hf
Allowable Stress Design

20. I-Beam Analysis effective width, bf Fb F1 hf F2 F3 F4 bw kd h F5
Steel Reinforcement F6 F7
h-hf < kd < h
Allowable Stress Design

21. I-Beam Analysis effective width, bf Fb F1 hf F2 F3 F4 bw h F5
Steel Reinforcement kd F6 F7 F8
h < kd
Allowable Stress Design

22. Simple Analysis effective width, bf fb hf a C bw T = As*fs h
Steel Reinforcement
a = 0.8*c
Strength Design

23. T-Beam Analysis effective width, bf fb hf a C bw T = As*fs h
Steel Reinforcement
a = 0.8*c
Strength Design

24. Face Shell Dimensions ASTM C90 Minimum Face shell thickness:
6” block = Minimum 1” Face Shell
8” block = Minimum 1 ½ “ Face Shell
10” block = Minimum 1 ½ “ Face Shell
12” block = Minimum 1 ½ “ Face Shell

25. Results
Axial Capacity
Flexural Capacity

26. ASD 24 Inch Spacing

27. ASD 48 Inch Spacing

28. SD 24 Inch Spacing

29. SD 48 Inch Spacing

30. Conclusion Below The Balance Point Above The Balance Point
Solid grouted equations are sufficient.
Above The Balance Point
Solid grouted design would not be conservative.
More Complex design should be used for compression controlled points.

31. Masonry Code Resources
American Concrete Association
Portland Cement Association
Masonry Standard Joint Committee
International Building Code