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

Origin of Masonry Old building material Random rubble masonry http://www.flickr.com/photos/repowers/3013423747/

Brick Brick making is estimated to be 10,000 to 12,000 years old. http://picasaweb.google.com/lh/photo/

Fired Brick http://en.wikipedia.org/wiki/Appian_Way

Grouted Brick Masonry Bearing wall construction Large scale use seen in The late 1800s Monadnock Building, Chicago http://www.ou.edu/class/arch4443/

Concrete Masonry Units Process of constructing CMU began in 1882. First CMU Cast were 30” units cast on site. http://www.boralbestblock.com/product-lines/

Concrete Masonry Units Mechanical Vibration Zero slump concrete Current production process highly automated http://www.archithings.com/search/Integrity

Design Provisions Uniform Building Code BOCA National Building Code (Building Officials and Code Administrators International) The Standard Building http://www.addebook.com/tech/

International Building Code Emerged in 1994 Phase out previous codes By 2000 Broad-based principles http://libguides.calpoly.edu/codes_caed

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. http://www.masonrysociety.org/

Goals Evaluate peak stress conditions Allowable Stress Design Strength Design

Allowable Stress Design Older analysis Widely used Elastic Behavior External Loads

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

Strength Design Newer analysis Limit states

Strength Design Newer analysis Probability of failure Statistical Analysis

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

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

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

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

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

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

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

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

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

Results Axial Capacity Flexural Capacity

ASD 24 Inch Spacing

ASD 48 Inch Spacing

SD 24 Inch Spacing

SD 48 Inch Spacing

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.

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