CMU Technological Preformances
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Performance Parameters and Properties
Property: Thermal resistance and Compressive strength
Units: R-value and psi
Description of property: The thermal ressistance of a CMU wall is an important property as it determins how efficiently the wall system preforms. The compressive strength is an important property as it affects the overall strength of the wall itself.
Pertinant test protocalls: The thermal ressistance and compressive strength are both measured by independant testing agencies or by the manufacturers. Many testing methods are availible including simulated thermal experiments and tests done on a compression machine.
Typical range of values: A typical R-value for CMUs is between 1 and 2. The compressive strength of a block must be an average of 1900 psi and no less than 1700 psi.
Codes or regulatory constraints: Both of these parameters are regulted by ASTM C90.
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Buyer's Guide
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Stakeholders
- Owner/End User
- Architect/Designer
- Engineer
- Builder
Performance Parameters
- Structural/mechanical
- Thermal
- Permeability
- Durability
- Indoor Air Quality
- Fire
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http://www.cca.org.nz/images/masonry.jpg
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The stakeholders involved with projects utilizing Concrete Masonry Units will be attracted to them or deterred while evaluating the performance parameters in respect to their specific project. Owners and/or end users will be involved when deciding a budget and defining the appropriate areas to spend and save money. CMU can offer many options for saving money yet still meeting other important performance parameter such as structural abilities and durability. Architects and engineers will analyze the performace of CMU with respect to the design and feasibility of the project they are delivering to the owner. Builders will be more involved with the cost, labor-intensiveness, storage, shipping and other values that will effect the construction process directly, not only as a material but as a process.
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FMEA Analysis
Failure Mode and Effects Analysis (FMEA) is a way for investigators to understand the different negative outcomes when a specific component of (in this case) a wall system fails. This analysis is used to help future owners, architects, builders, and inhabitants prevent a potentially catastrophic event. Concrete Masonry Units are discussed in the following table.
| Functions |
Elements |
Modes |
Causes |
Effects |
| Structural/Mechanical |
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- Water Absorption
- Cracking
- Poor Joint
- Rusting
- Breaking
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- Raked/Struck Joint
- Water Penetration
- Overload
- Expansion/Shrinkage
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- Wind Penetration
- Water Penetration
- Loss of Strength
- Destabilization
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| Permeability |
- Mortar & Grout
- Vapor Barrier
- CMU
- Joint
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- Water Absorption
- Tearing
- Cracking
- Rusting
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- Poor Joint
- Wind Penetration
- Raked/Struck Joint
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- Hot and Cold Spots
- Unwanted Pollutants
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| Indoor Air Quality |
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- Water/Pollutant Absorption
- Finishing
- Tearing
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- Wind Penetration
- High VOC Indoor Finishes
- Poor Joint
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- Poor IAQ
- Human Health Risks
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| Thermal |
- CMU
- Insulation
- Vapor Barrier
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- Water Absorption
- Disintegration
- Tearing
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- Low R-Value
- Wind Penetration
- Water Penetration
- Infestation
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- Inefficient Energy Performance
- Loss of Heat
- Infestation
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Third Party Evaluation
- journalsip.astm.org/JOURNALS/CEMENT/PAGES/186.htm- This link is from the website of Journals Provided by ASTM which is a very respectable source. It provides a link to a document pertaining to concrete masonry units. This documents contains a variety of information ranging from how concrete masonry units should be stored to installed and even how to clean concrete masonry units.
- Northwest Concrete Masonry Association -nwcma.org- The website for the Northwest Concrete Masonry Association provides a large amount of resources. These resources range from CMU codes to a photo gallery. The website even provides technical specifications such as fire resistance and mortar specifications.
- National Concrete Masonry Association-ncma.org- This is the website for the National Concrete Masonry Association. This website provides the most information among concrete masonry websites. This site provides links to directories, information on how to get concrete masonry certified by the National Concrete Masonry Association. A link to resources pertaining to concrete masonry is also provided.
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Relevant Trade Associations
- National Concrete Masonry Association-NCMA
- Masonry Contractors Association of America-MCAA
- Virginia Masonry Association-VMA
- Portland Cement Association-PCA
- Carolinas Concrete Masonry Association-CCMA
- New England Concrete Masonry Association-NECMA
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Lessons Learned Analysis
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Phase-Out Analysis and Lessons Learned
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Project/Task:
CMU Technological Peformances
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Date:
10/03/2008
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Team Name:
Team 1
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Members:
Loomer, Naehle, Keesling, Vaughn, Wisch
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Subtask
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What Worked
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What Didn't Work
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Ways to Improve
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Review of the assignment
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Pointing out important details
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Distractions
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Stay on task
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Division of work
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Each member picking a desired section
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Not all tasks required the same amount of work
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Have team leader divide tasks evenly
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Compilation of Powerpoint slides
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Members complete a slide for their section and send to a designated member who compiles and turns in the slides
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Not all slides were in the same format
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Predetermine what format should be used
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Team review of work
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Each member critiques another members work
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Not all members were available to meet
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Better scheduling
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Target Analysis: How well did the project/team do...
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In achieving goals and meeting project objectives?
We were able to complete the assignment without any major difficulties.
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At meeting deadlines and the final completion date?
Aside from one, all members were able to attend all meetings
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At monitoring and staying within project budget?
N/A
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At communicating with stakeholders?
N/A
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Resources Assessment: were the allocated resources appropriate, sufficient, and efficiently used?
Yes, all necessary information was provided
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Lessons Learned: what are the key lessons that can be applied to future projects?
Improvements in planning and communication are the key thing that we need to work on in coming projects.
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