7-25 Payment will be made under: 1
Pay Item Pay Unit Repair of Jointed Concrete Pavement Slabs Square Yard Select Material, Class IV Ton Patching Concrete Pavement Spalls Square Foot SECTION 724 2 NONWOVEN GEOTEXTILE INTERLAYER 3
724-1 Description 4
Furnish and install a non- woven geotextile interlayer at locations shown on the plans. 5 Schedule a Pre- Pave Meeting with the Engineer at least 3 weeks prior to paving to discuss 6 installation and construction procedures for the nonwoven geotextile interlayer with 7 representatives from the Contractor including Paving Superintendent, Subcontractor and 8 Geotextile Manufacturer. Submit for approval a Process C ontrol Plan addressing the 9 nonwoven geotextile interlayer certification process in accordance with Article 700- 1. 10
724-2 Materials 11
The geotextile interlayer shall be constructed of a non- woven needle -punched geotextile, with 12 no thermal treatment (calendaring or IR). The material shall be resistant to chemicals, 13 mildew, and rot and shall not have any tears or holes that will adversely affect the in -situ 14 performance and physical properties of the installed material. 15 Furnish with each shipment a Type 3 Certification in accordance with Article 106 -3 certifying 16 that the paving mat is a non- woven needle -punched geotextile with no thermal treatment 17 (calendaring or IR) meeting the requirements in Table 724- 1. 18
7-26 Table 724- 1
PHYSICAL PROPERTIES OF NON -WOVEN GEOTEXTILE INTERLAYER Property Test Method Units Value Minimum Mass per unit area ASTM D 5261 oz/yd2 15.0 Minimum thickness under load
a.at 2 kPa (0.29 psi)
b.at 20 kPa (2.9 psi)
c.at 200 kPa (29 psi) ASTM D 5199 in (a) 0.12
b.0.10
c.0.04 Minimum wide -width tensile strength ASTM D 4595 lb/ft 685 Maximum wide -width elongation ASTM D 4595 % 130 Minimum water permeability in normal direction under load (pressure) at 20 kPa (2.9 psi) Mod. ASTM D 5493 or ASTM D 4491 ft/s 3.3x10-4 Minimum in -plane water permeability (transmissivity) under load (pressure)
a.at 20kPa (2.9 psi)
b.at 200kPa (29 psi) Mod. ASTM D 6574 or ASTM D 4716 ft/s (a) 1.6x10-3
b.6.6x10-4 Minimum weather resistance retained strength ASTM D 4355 at 500 hrs. exposure % 60 Alkali resistance, minimum polypropylene/polyethylene Manufacturer certification of polymer % 96 Requirements must be met for 95% of the samples. 1
724-3 General Requirements 2
A trained and experienced installer, certified by the Geotextile Manufacturer, shall be present 3 on-site during the installation of the geotextile and until the Engineer accepts that the crew has 4 a comfort level working with this material. Handle and store geotextiles in accordance with 5
Article 1056 — 2. 6
Ensure that any potential for keying of the two cementitious layers is minimized through 7 proper repair techniques. Clean the underlying surface to remove loose debris before 8 applying the interlayer. Roll th e geotextile out on the underlying layer. The geotextile shall 9 be tight and without excess wrinkles and folds. No more than 650 feet of geotextile shall be 10 installed in advance of the paving operation at a given time. The interlayer shall be placed no 11 more than 24 hours before concrete placement , unless otherwise approved by the Engineer . 12 Keep driving on the interlay to a minimum , restricted to concrete paving operations only . 13 Tight radius turns and excessive acceleration and braking shall be avoided. 14 The geotextile shall be secured to the underlying layer with pins or nails punched through 15 2 to 2.75 inch galvanized washers or disks every 6 feet or less. Additional fasteners shall be 16 used as needed to ensure that the geotextile does not shift or fold before or during concrete 17
Source: North Carolina Standard Specifications for Roads and Structures, 2024 Edition. Pages 335–336 of 857.