Hi, Mike. I don't know of a list of approved _materials_ but by posting your question to the the Highways Community Exchange Detectable Warnings discussion board you have got your question in front of the right group to get an answer. My perception is that from the approved products it would be possible to back out the materials, but approaching it from the approved materials side would get you down the road to standardization. best regards, Mike Mark Mark R. Chandler, PE, CMfgE
U.S. DOT - FHWA Wisconsin Division
office: 608-829-7514
mark.chandler@fhwa.dot.gov
www.fhwa.dot.gov/widiv/index.htm Field Operations Engineer
Asst Coord for WisDOT's SW & NE Regions

Mike, materials for detectable warnings in NY are driven mainly by the physical property requirements outlined in the specification (i.e. 55 MPa and max. 1% freeze-thaw loss for "embedded units"). Any manufacturer who certifies that their material can meet these requirements, (as well as the dimensional tolerances), is then approved for a field trial placement. Examples of materials submitted for approval include precast pavers, polymer modified concrete, cast iron, stainless steel, ceramics, granite, and plastics. Following web address includes current specifications as well as a link to the Approved List: www.dot.state.ny.us/cmb/consult/eib/files/ei06010.pdf

Mike, I believe Indiana DOT is attempting to rearrange their specification to make it materials-based. Please contact me directly if you would like some INDOT contact information.

Hi Mark,
The reason no such list exists is because the tests are done on finished products and not on (raw) materials. Therefore, APL's are on finished products that manufactures produce that meet ADAAG product guidelines on dome height and spacing, product size etc … Another reason why I think it's not done on materials as the APL's would be very complex and long as there are a myriad of materials that make up DW's. Also, any material could be used, such as leather as long as they meet ADAAG guidelines, but this does not mean that the finished product would be suitable for the specific application it is intended for. Kind regards, Sandro Pinto
Engineered Plastics, Inc. Armor Tile 300 International Drive
Suite 100
Williamsville, NY, 14221
USA M: 716-818-6646
T: 800-682-2525 Ext.111
F: 800-769-4463
www.armor-tile.com
www.advantagetactile.com

In our fair state the detectable warnings are evaluated and listed by material type. We have evaluated DW made from concrete paving stones "concrete pavers", those from in-laid concrete panels "inlaid panels" and those from inlaid plastic/ceramic tiles "inliad tiles" (we do not allow glue down tiles). Our position paper for detectable warnings includes a section for each material type so each has its own set of testing and acceptance criteria. We currently have not evaluated any metal products so our position for these has not yet been developed. Incidentally, we have yet to approve a plastic/ceramic product for various reasons.

DelDOT's Specification special provisions for detectable warnings includes the following regarding materials: "The Contractor shall use either of the following material systems: 1. Precast concrete, or fired clay brick, paver units, each with the truncated dome pattern, set on the concrete sidewalk surface. For this application, the Contractor shall use mortar for adhesion to the sidewalk surface and for joint filling. 2. Cast iron plates, each with the truncated dome pattern, set on the concrete sidewalk surface. The plates shall be achored down according to manufacturer's recomendations. The Engineer will not approve stamping systems, applied membranes, or ceramic tiles." Please contact me if you want any additional information. Thanks.

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