Visual Mockup for concrete

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Author Message Robin E. Snyder Senior Member Username: robin Post Number: 612 Registered: 08-2004 Posted on Wednesday, July 29, 2015 - 11:36 am:    Is there any standard for distance for viewing visual mockups for concrete? In this case, the smaller sample (2 x 2) was approved for color, but the full-size mockup doesn't match. Contractor is claiming that it "matches" when viewed from 20 feet away, which, allegedly is industry standard. I can't find anything to support or negate. Ellis C. Whitby, PE, CSI, AIA, LEEDŽ AP Senior Member Username: ecwhitby Post Number: 259 Registered: 03-2003 Posted on Wednesday, July 29, 2015 - 12:29 pm:    I believe that PCI MNL 117 references 20 feet as a minimum viewing distance, Steven Bruneel, AIA, CSI-CDT, LEED-AP, EDAC Senior Member Username: redseca2 Post Number: 502 Registered: 12-2006 Posted on Wednesday, July 29, 2015 - 02:55 pm:    It can be difficult to get a small (2 x 2) cast-in-place concrete sample that accurately shows the results you will get in the field. The actual field installation is measured in cubic yards while the sample was probably made in a very small quantity - one teaspoon or two? George A. Everding, AIA, CSI, CCS, CCCA Senior Member Username: geverding Post Number: 800 Registered: 11-2004 Posted on Wednesday, July 29, 2015 - 03:16 pm:    Specifically, PCI MNL 117 article 1.5.4 "Visual Mockups and Initial Production Approval of Architectural Finishes". There is also a commentary paragraph adjacent to the article. George A. Everding, AIA, CSI, CCS, CCCA Senior Member Username: geverding Post Number: 801 Registered: 11-2004 Posted on Wednesday, July 29, 2015 - 03:20 pm:    Also 2.9 Michael Chusid, RA FCSI CCS Senior Member Username: michael_chusid Post Number: 64 Registered: 10-2003 Posted on Wednesday, July 29, 2015 - 06:50 pm:    Assume production concrete WILL NOT match small samples. Concrete color varies with minute differences in curing method and time, w/cm ratio, form surfaces, etc. This is especially true for site cast concrete. See my article from Construction Specifier at http://www.daviscolors.com/Downloads/Literature/DC618.pdf Michael Chusid, RA FCSI CCS www.chusid.com www.buildingproduct.guru Guest (Unregistered Guest) Unregistered guest Posted on Thursday, July 30, 2015 - 11:53 am:    Anyone know if the ACI is similar to the PCI for mockup viewing? What if this isn't precast? Ronald L. Geren, FCSI, AIA, CCS, CCCA, SCIP Senior Member Username: specman Post Number: 1330 Registered: 03-2003 Posted on Thursday, July 30, 2015 - 12:29 pm:    I have a 2007 edition of the ACI Manual of Practice, and ACI 303R-04 "Guide to Cast-in-Place Architectural Concrete Practice" states in Section 2.1.1 the following: "General acceptance criteria--Architecturally acceptable concrete surfaces should be aesthetically compatible with minimal color and texture variations and minimal surface defects when viewed at a distance of approximately 20 ft (6 m) or more as agreed upon by the architect, owner, and contractor, or as otherwise specified." Ron Geren, FCSI, AIA, CCS, CCCA, SCIP www.specsandcodes.com Sheldon Wolfe Senior Member Username: sheldon_wolfe Post Number: 872 Registered: 01-2003 Posted on Thursday, July 30, 2015 - 03:06 pm:    "as agreed upon by the architect, owner, and contractor" Good one, ACI! George A. Everding, AIA, CSI, CCS, CCCA Senior Member Username: geverding Post Number: 802 Registered: 11-2004 Posted on Thursday, July 30, 2015 - 03:33 pm:    This illustrates that reference standards are minimum standards. As one of my mentors, Ed Glock, is fond of pointing out, ASTM C90 allows a chip the size of a quarter in the face of an exposed concrete block. Is this acceptable? It depends on the project, how the block is being used, what the owner's and architect's expectations are... But the reality is that if you just specify ASTM C90 without stipulating stricter requirements, don't be surprised to see chips in 5% of your units. Read and understand the reference standards in your specification.