CATEGORY 900 MATERIALS SECTION 925 — DETECTABLE WARNING SURFACE
925.01 General
Detectable warning surfaces shall conform to the current accessibility guidelines of the Americans with Disabilities Act (ADA). The Office of Materials Technology (OMT) maintains a Qualified Products List (QPL). Manufacturers seeking inclusion of their product on the QPL shall submit certified test results showing conformance to the properties in 925.07, as well as installation instructions and the types of adhesives and sealants required.
925.02 Composition
Warning surfaces shall be either flexible or rigid. If there is a change in the composition of a qualified product, the manufacturer shall notify OMT and submit new test results showing conformance with 925.07.
925.02.01 Pavers. Type III Brick Pavers shall conform to the requirements of C 902, Class SX,
Type 1, and Application PX. The pavers shall be 2-1/4 in. x 4 in. x 8 in. with square edges and a surface meeting 925.03.
925.03 Configuration and Dimensions
The warning surface shall consist of a system of truncated domes having a base diameter of 0.9 in. to 1.4 in., a top diameter 50 percent to 65 percent of the base diameter, and a height of 0.2 in. The domes shall be arranged in a square grid with center to center spacing of 1.60 in. to 2.40 in.
925.04 Color
The color shall be homogeneous across the surface of the material and contrast with adjoining surfaces.
925.05 Identification
The top surface shall have an identifier that uniquely distinguishes the manufacturer. Brick pavers are excluded. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS C 925 — DETECTABLE WARNING SURFACE
925.06 Requirements
testing. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS TYPE DESCRIPTION PHYSICAL TEST REQUIREMENTS Type I Cast in Place A, B, C, D, E, G Type IIa Surface Mount, Rigid A, B, C, D, E, G Type IIb Surface Mount, Flexible A, B, C, D, F, G Type III Brick Pavers 925.02.01 Type IV Prefilled Pavers A, B, C, D, G PROPERTY TEST METHOD SPECIFICATION LIMIT A Slip Resistance Coefficient C1028 (dry method) 0.80 min B Abrasive Wear, index C501 150 min Fade (UV) Resistance/Color Retention D4587 Fade or Change in color after 2000 hrs less than ΔE =5* D Freeze/Thaw Resistance C1026 No disintegration E Adhesion/Bond Strength, pull off C482/C 882(as appropriate) No adhesion failure F Adhesion/Bond Strength, peel D903/D429 (modified as appropriate) No adhesion failure G Contrast Contrast percentage formula** using E1349 to determine cap Y brightness/light reflectance values (LRV) Current ADA requirement*** *Chromaticity coordinates (L*a*b* system) checked in conformance with D2244, before and after test. **Contrast % = [(B1 – B2)/B1] x 100, where B 1 = (LRV) of the lighter area, and B 2 = (LRV) of the darker area ***For the purpose of determining whether a material meets acceptable contrast criteria, use actual cap Y brightness of detectable warning surface, and assume a value of 15 for the cap Y brightness of cured concrete, or a value of 3 for asphalt wearing surfaces to determine percentage difference. Detectable warning surfaces to be installed on other materials are required to undergo additional 1050925.07 PHYSICAL PROPERTIES 926 — FOAMED ASPHALT STABILIZED BASE COURSE MIX CATEGORY 900 MATERIALS SECTION 926 — FOAMED ASPHALT STABILIZED BASE COURSE MIX
926.01 Mix Requirements
Develop a mix consisting of Reclaimed Asphalt Pavement (RAP), Recycled Portland Concrete (RC), aggregate, and foamed asphalt binder. Include lime, Portland cement, and fly ash as necessary to increase the fines to meet the design parameters in Table 926 A and Table 926 B. Select a PG 64-22 asphalt binder that provides the required asphalt foaming characteristics and mix properties. Do not use polymer modified asphalt binders. Table 926 A - Aggregate Blend Requirements GRADATION (T 27) Sieve Size Percent Passing 1 1/2 in. (38 mm) 100 3/4 in. (19 mm) 65 – 100 No. 4 (4.74 mm) 50 – 70 No. 200 (75 µm) 1 – 8 OTHER PI (T 90) < 10 % Table 926 B - Foamed Asphalt Stabilized Base Course Mix Requirements DESIGN PARAMETERS VALUE Aggregate Blend Compaction: T 180D, Max Dry Density, pcf ≥120 Specimen compaction: Marshall compaction: T 245 - number of blows per face, or 75 Gyratory compaction: T 312 - number of gyrations 30 Indirect Tensile Strength: modified T 283 Minimum Wet Tensile Strength, psi 45 Minimum Wet Tensile Strength, psi, for material stockpiled >2 days Minimum Tensile Strength Ratio (TSR), % 55 Foamed Asphalt Expansion Characteristics @ 160, 170, & 180 C Minimum Half-Life of Foamed Expansion, sec (1) Minimum Expansion Ratio (2) 8 Note 1: Total time for foamed asphalt to settle to half of the maximum foamed volume. See Section A.1.3.4 of the Wirtgen Cold Recycling Technology Manual (2010) for the half-life test procedure. Alternate suitable equipment can be substituted for the Wirtgen WLB 10 S laboratory unit. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS