CATEGORY 500 PAVING SECTION 511 — OPEN GRADED FRICTION COURSE
511.01 Description
Construct Open Graded Friction Course (OGFC) according to Section 504 except as specified.
511.02 Materials
Open Graded Friction Course Section 927 Performance Graded Asphalt Binders Section 904 Production Plants Section 915
511.03 Construction
511.03.01 Demonstration. Construct a demonstration strip of at least 100 tons outside the project
limits to demonstrate that a satisfactory OGFC mix can be produced and placed before proceeding with the actual work. Construct a new strip if a project carries over to a new season or whenever there is a change in the mix design. Use pavers and rollers that conform to 504.03.01. A material transfer vehicle may be used to construct the demonstration strip. The demonstration strip may be waived for projects less than 200 tons or as directed. Material not meeting specification requirements may be subject to penalty or removal and replacement.
511.03.02 Hauling Units. Dry soap powder may be used with the release agent specified in
915.02(f). Raise truck beds to drain excess water and/or release agent before loading with OGFC. The time between plant mixing and shipment shall not exceed one hour. Stored material shall be of no less quality than mixtures discharged directly into hauling vehicles. Each load shall be completely covered with a securely fastened full tarp containing no holes or rips.
511.03.03 Weather Restrictions. Place OGFC only when the ambient and surface temperatures
are at least 50 F and in accordance with polymer-modified materials as specified in 504.03.02. Do not place OGFC if the existing surface is wet or frozen. 511.03.04 Material Transfer Vehicle (MTV). Use a material transfer vehicle (MTV) when placing OGFC. The MTV shall perform additional mixing of the OGFC material and then deposit the mixture into the paver at a uniform temperature and consistency. An MTV may be used when placing OGFC for a permeable pavement system but is not required. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
511.03.05 Pavement Thickness. The thickness of the pavement shall be as specified. 504.03.13
(Thin Lift) is not applicable.
511.03.06 Tack Coat. Apply tack coat at a rate between 0.04 gal/yd2 to 0.06 gal/yd2. Reduce the
application rate to 0.02 gal/yd2 to 0.04 gal/yd2 on freshly placed bituminous surfaces. Do not apply tack coat to permeable pavement systems using OGFC. 511.03.07 Compaction. Compact the surface using the number of passes determined from the satisfactory construction of the demonstration strip. The rollers shall follow the paver according to the QC Plan. The rollers shall be equipped with a watering or soapy watering system that prevents material from sticking. No vehicular traffic of any kind is permitted on the surface after rolling until the OGFC has completely cooled to 125 F. Continued rolling will not be allowed to prevent crushing the aggregate. The finished OGFC surface shall be even with no pockets and meet the grades shown. Do not use OGFC in areas designated for storage.
511.03.08 Joint Construction. Clean and tack the vertical face of the longitudinal joint before
placing adjoining material. Construct butted (not lapped) longitudinal joints so that the joint is smooth, well-sealed, and bonded .
511.03.09 Pavement Profile. As determined.
511.03.10 Mix Sampling and Testing. Refer to 504.03.11
511.03.11 Testing for Pavement Density (Air Voids). Normal density requirements are waived.
511.04 Measurement and Payment
Open Graded Friction Course will be measured and paid for at the Contract unit price per ton. Payment will be full compensation for furnishing, hauling, placing all materials, material transfer vehicle, anti-stripping additive, tack coat, setting of lines and guides where specified, and for all material, labor, equipment, tools, required testing, and incidentals necessary to complete the work. Material produced for the demonstration strip will not be measured but the cost will be incidental to the item OGFC.
511.04.01 Price Adjustment for OGFC. Mix adjustments for gradation and asphalt content will
be as follows: Use Steps 1 through 5 of MSMT 735 in conjunction with the physical properties in Table 901 D and the following: 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
6.Determine the Composite Mixture PWSL (CMPWSL) for each lot: CMPWSL = f1*PWSL1+f2*PWSL2+ f3*PWSL3+f4*PWSL4+ f5*PWSL5 f PWSL1 = Asphalt content PWSL2 = Aggregate passing the 3/8" (9.5mm) Sieve PWSL3 = Aggregate passing the #4 (4.75mm) Sieve PWSL4 = Aggregate passing the #8 (2.36mm) Sieve PWSL5 = Aggregate passing the 200 (75µm) Sieve f = Sum of price adjustment factors Determine the PWSL for each property from MSMT 735, Table 1.
7.Use the following table with the price adjustment factors (f) to compute CMPWSL: Properties Factor (f) Asphalt content 64 Aggregate passing the 3/8" Sieve 9 Aggregate passing the #4 Sieve 9 Aggregate passing the #8 Sieve 9 Aggregate passing the 200 Sieve 9 Report the CMPWSL and PWSLs to the nearest whole number.
8.Use the CMPWSL determined in Steps 6 and 7 for the Mixture Pay Factor.
511.04.02 Dispute Resolution. 915.02.03
2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS 512 — SURFACE ABRASION CATEGORY 500 PAVING SECTION 512 — SURFACE ABRASION
512.01 Description
Perform Surface Abrasion (SA) using high velocity steel shot to modify the pavement surface texture.
512.02 Materials
Not Applicable. Equipment.
a.Surface Abrasion Machine. Perform texturing with a machine designed and built for high production pavement texturing. The machine shall be capable of maintaining a minimum average production rate of 1800 yd 2/hour for pavement surfaces with a minimum width of 48 in. per pass. The machine shall be capable of separating and recycling the steel shot employing the High Velocity Impact Method (HVIM), and shall vacuum and contain the abrasion debris into a self-contained unit with a minimum capacity of 3 yd
3.The SA equipment shall be equipped with controls capable of monitoring and controlling the vehicle speed and shot velocity. Self-contained lighting is required for night operations.
b.Steel Shot. Use steel shot material which does not exceed the EPA Toxicity Characteristic Leaching Procedure (TCLP) test thresholds for the eight metals which define the RCRA toxicity characteristics according to 40 CFR 261.24 (arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver). Submit certification as specified in TC 1.03 and an MSDS for the steel shot to be used.
512.03 Construction
512.03.01 Quality Control Plan. Submit a Quality Control Plan (QCP) for approval at least
30 days prior to construction operations. The QCP shall show the methods proposed to control the equipment and abrasion operations. Discuss the QCP requirements at the pre-construction and progress meetings. The QCP shall contain, at a minimum:
a.Key Personnel and contact information.
b.Cleaning and maintenance schedule for the SA equipment. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS
Source: Maryland Standard Specifications for Construction and Materials, 2025 Edition. Pages 678–680 of 1,113.