P-406.pdf

ASPHALT REINFORCEMENT MESH P-406-1

DIVISION 2

ITEM P-406 ASPHALT REINFORCEMENT MESH

DESCRIPTION

406-1.1 ASPHALT REINFORCEMENT MESH. This work shall consist of furnishing and installing the specified type of asphalt reinforcement mesh at the locations and as per the details in the contract plans.

MATERIALS

406-2.1 Asphalt reinforcement mesh shall consist of fiber glass strands coated with a protective elastomeric polymer and pressure sensitive adhesive backing. In addition, the reinforcement mesh shall have the following physical characteristics and mechanical properties:

PRODUCT PROPERTIES METHOD / UNITS Type 2

Mesh Grid Size (Type)

(Center to Center) Callipered (inches) 0.5 in. x 0.5 in.

Roll Width (Min) Measured (ft) 5

Mass / Unit Area (Min.) ASTM D 5261-92 (oz/sq. yd) 16

Tensile Strength (Min.)

(Across Width) ASTM D 6637 (lb./in.) 1120

Tensile Strength (Min.)

(Across Length) ASTM D 6637 (lb./in.) 560

Elongation at Break ASTM D 6637(%) Less than 3%

Melting Point ASTM D 276 (oF) Over 425o

406-2.2 Geotextile paving fabrics will not be considered as an alternate to asphalt reinforced mesh. One approved source of asphalt reinforcement mesh is Saint–Gobain Technical Fabric’s GlasGrid. For information, contact their designated representative at Tensar International Corp., Morrow, GA

(888) 828-5126.

SUBMITTALS AND CERTIFICATIONS

406-3.1 Submittals of "Shop and Setting Drawings", "Working Drawings", "Catalogue Data" and

"Certifications" for review shall be submitted in accordance with appropriate sections of the General

Provisions. Submittals and Certifications required are as follows:

A. Catalog data and certification showing that the asphalt reinforcement mesh meets the specified requirements.

B. Asphalt reinforcement mesh product sample approximately 12 inches by 8 inches or larger.

ASPHALT REINFORCEMENT MESH P-406-2

C. Manufacturer’s installation instructions and general recommendations.

CONSTRUCTION METHODS

406-4.1 GENERAL. Prior to use, store reinforcement mesh rolls in unopened packaging vertically (on end) under dry covered conditions free from dust dirt and moisture to prevent roll distortion and contamination. Store the product at temperatures above minus 20 degrees o F. Do not place mesh reinforcement when the surface is wet, or contaminated with oil, soil or excessive dust. Do not place asphalt during wet or freezing weather that prevents conformance with specified requirements.

406-4.2 ADHESION TEST. The CONTRACTOR shall test to the satisfaction of the COR that proper adhesion exists between the asphalt reinforcement mesh and the underlying pavement.

1. This test can be done on the reinforcement mesh after it is placed or it can be done on a minimum one square yard sample cut in a square shape.

2. Place the reinforcement mesh on the surface to be paved.

3. Apply adequate vertical pressure to fully activate the pressure sensitive adhesive, e.g., by use of a rubber tire roller or other means approved by the manufacturer.

4. Insert a hook of a spring balance (such as that used for a fish scale) under the center of the pavement mesh sample. Pull the spring balance up until the sample just starts to pull loose and record the gauge reading. In the event that 20 pounds or more of force is required to pull the sample up from the road surface, sufficient adhesion has taken place and the paving operation can begin.

5. In the event that the sample does not have 20 pounds of adherence, identify if the rolling operation to activate the pressure sensitive coating needs to be improved or if there is any cleanliness or moisture issues present. Resolve these issues prior to installing the rest of the paving mesh, and prior to placing asphalt on top of the mesh.

6. Verify proper adhesion with this test once every 1,000sf or as directed by the COR.

406-4.3 PREPARATION AND INSTALLATION.

A. Surfaces shall be mechanically cleaned by sweeping and vacuuming and be free of oil, vegetation, sand, dirt, water, gravel and other contaminants prior to placement of interlayer reinforcing.

B. Before the reinforcement mesh is laid, the existing pavement surface shall be prepared.

Seal cracks between 1/8 inch and 1/4 inch with an acceptable crack filler or as per the plan details. Repair wider cracks using a method that provides a level surface. All holes shall be filled with hot asphalt and compacted level with adjacent surfaces. If specified, place a truing and leveling course in accordance with the contract plans.

ASPHALT REINFORCEMENT MESH P-406-3

C. Cracks shall be marked and recorded prior to and after the true and leveling course.

Identifying and preserving the crack location will ensure that the mesh is properly centered on each crack when full mesh coverage of the site is not specified.

D. Asphalt Reinforcement Mesh Placement:

1. Surface temperature shall be between 40 degrees o F and 140 degrees o F prior to laying the mesh reinforcement.

2. The placement surface must be dry. Since moisture affects the adhesion of the mesh to the pavement surface, mesh placement should not be done if rain may occur prior to covering the mesh with an asphalt mat overlay. Mesh that is placed and will not adhere due to moisture shall be removed and replaced at the CONTRACTOR’s expense.

3. Reinforcement mesh shall be laid out by mechanical means or by hand using sufficient pressure to eliminate ripples. Remove any ripples by pulling the grid tight. Cutting of the grid may be done on tight radii to prevent ripples.

4. Lap transverse joint in the direction of the paving 3 inches to 6 inches, longitudinal joints shall be overlapped 1 inch to 2 inches or as recommended by the manufacturer, whichever is greater.

5. After placement, activate self-adhesive glue by rolling with a rubber coated drum roller or a pneumatic tire roller until properly adhered. In no instance, shall steel wheeled or vibratory rollers be used. Rolling shall continue until the adhesive is activated and the mesh is bonded to the truing and leveling course. Generally, this can be accomplished in one or two roller passes.

During rolling operations, roller tires shall be kept clean to the satisfaction of the COR.

Reinforcement shall be laid and rolled over ironworks (i.e. manhole covers, drainage grates, etc.). Once the mesh has been rolled, these portions of the mats covering the ironworks shall be removed by cutting the reinforcement mesh with a utility knife or other similar tool.

6. Construction and emergency vehicles will be allowed to run on the reinforcement mesh after rolling. However, any damaged or de-bonded sections of the mesh resulting from these vehicles, as determined by the COR, shall be immediately replaced with new mat sections taking care to place the adhesive backing down and to overlap the mesh already in place. As before, replacement sections shall be rolled in accordance with manufacturer’s recommendations. Mesh shall be rolled until the adhesive is activated and the replacement mesh section is bonded to the truing and leveling course. Any dirt, dust or other contaminants deposited on the mesh covered truing and leveling course by the construction equipment, maintenance vehicles, ARFF vehicles and aircraft traffic shall be removed by mechanical sweeping or vacuuming the surface. No additional payment will be made to replace sections of mats damaged by construction equipment, maintenance vehicles, ARFFvehicles or aircraft traffic. No payment will be made to sweep or vacuum the surface, or to remove contaminates deposited by such traffic.

ASPHALT REINFORCEMENT MESH P-406-4

7. Protect the asphalt reinforcing mesh until placement of the finished asphalt topping. Repair damaged sections prior to placement of finished asphalt topping.

E. Use and Placement of Tack Coat – Because the asphalt reinforcing mesh has a self adhesive backing, a tack coat is not required for the installation. However, if a tack is specified for other reasons, the tack must be allowed to break and cure before any additional asphalt is placed. Breaking is defined as the point at which the brown colored tack turns black. Curing occurs when the residual asphalt cement contains no solvents

(water or any volatiles). After the tack has broke and cured, the adhesion test should be done prior to placing asphalt, and prior to asphalt trucks running on the tacked surface.

Proper tack location (under or over the mesh) is based on site specific environmental conditions and the specific type of tack being used. Verify the proper application location with the manufacturer prior to installation.

END OF SECTION