The ability of asphalt to withstand Tensile Stress is limited. When existing asphalt or concrete pavements are over-laid with new asphalt, cracks and joints will penetrate through the new asphalt layer within a very short period of time. This usually results in fast deterioration of the pavement, especially in areas where water can penetrate the pavement structure. By applying reinforcement the tensile stresses are reduced and distributed over a large area, and reflective cracking can be delayed or even prevented. Also surface cracking, caused by for example frost heave, can be treated well by asphalt reinforcement.
Extensive research and field experience have resulted in a number of requirements for effective reinforcement products:
High tensile strength
High stiffness EA (which is elastic modulus times cross sectional area) of the reinforcing material, even under creep conditions
No damage to the product while installing and overlaying with asphalt
Good bond between the new overlay, the reinforcement and the old pavement
The reinforcement should remain flat during the whole Construction process
Low coefficient of thermal contraction/Expension
Other important requirements are fast and easy application of the reinforcement, and easy and environmental friendly removal at the end of pavements life time.
Transverse & longitudinal cracks at PCC slab joints, which are Thermal and Load associated
Transverse & longitudinal (non-joint) cracks, which are Thermal and Load associated
Lane widening joints ACC interface which are Thermal and Load associated
Block cracking, ACC pavements, which are Thermal and Material associated
Fatigue or Alligator cracks which are Load associated
Utility cuts and pavement patches, which are Load associated.
GlasGrid® is an exceptionally strong reinforcing material, developed specially for pavements. It consists of glass fibre strands, arranged in a grid structure, covered with a polymer coating and a pressure sensitive adhesive. There is no loss of strength at paving temperatures and no damage during handling and paving operations.
High Tensile Strength: High modulus, E, fibre glass exhibits a tremendous strength to weight ratio and is up to 20:1 over asphalt concrete (20°C or 68°F), GlasGrid® clearly provides the stiffness required to redirect crack energy.
Low Elongation: The stress-strain diagram for glass is virtually a straight line of nearly vertical slope. This indicates that the materials is very stiff and resists deformation. GlasGrid® exhibits less than 5% elongation at break.
No Long- Term Creep: Many reinforcement materials that appear to be initially stable, exhibit creep deformation due to constant loading over long periods of time. Fibre glass exhibits no creep. This assures long term performance
Cross Sectional Area: Sufficient cross sectional “Area, A”multiplied by the “Modulus, E” of the materials (= AE) is required to redirect crack energy. The research conducted at Texas A&M shows GlasGrid® meets this requirement.
Asphalt Compatibility: The specially formulated polymer coating was designed to deliver high asphalt compatibility. Each fibre is completely coated to insure no slippage within the composite asphalt.
Thermal Stability: The melting points of fibre glass is very high which insures stability when subjected to the excessive heat of paving operation.
Chemical Stability: The specially formulated polymer coating was designed to provide protection against a wide range of chemical attack.
Physical Durability: The specially formulated polymer coating provides protection from physical abrasion. Additionally, coated fibre glass is resistant to biological attack, UV light, and weather.
Pavement Reinforcement Mesh.
Complete all crack sealing, pothole filling, base repairs, leveling course applications, etc.
Surface must be:
Clean and dust-free
Between 5° C * (40°F**) and 60°C (140°F)
Tack coats are optional. GlasGrid® is self-adhesive.
In order to preserve adhesive properties GlasGrid® must be stored inside a dust-free environment and kept dry at the job site.
GlasGrid® representative must be present during installing.
1. USING A FABRIC TRACTOR
Load roll onto front of tractor. Always load the red colored end of the core on the same end each time to allow placement of mesh with the self-adhesive side down.
Roll with rubber tired roller or with specially designed fabric tractor.
Pave with 40 MM (or more) of asphalt concrete layer.
2. MANUAL PROCEDURE, INSTALLATION PROCEDURE
Load roll on back of pick-up truck. To ensure that the mesh will always unroll with the sticky side face down, load so that the red coloured end of the core is on the same side of the truck each time.
Secure the roll with locking device.
Secure start of roll on pavement as the truck slowly moves away.
For shorter pieces pull mesh off roller to desired length. Cut with utility knife and lay by hand.
Roll only with rubber tired roller. Roller must be kept clean.
Pave with 40 MM (or more) of asphalt concrete layer.
For 8501, 8502, 8511, 8512 & 8550
Test for Proper Adhesion
Cut 1 m2 of GlasGrid®
Place on area to be paved.
Activate self-adhesive glue by rolling with a rubber tired
roller or by walking on the sample.
Insert hook of spring balance under center of GlasGrid®piece.
Pull upwards until GlasGrid® starts to pull from the surface.
Record result in kg (or lb).
If 5 Kg (approx, 11 lbs) or more, OK to pave. Stop immediately if GlasGrid®moves or ripples.
If less than 5 Kg (approx, 11 lbs), Do not pave with GlasGrid®.
Workers must wear gloves while handling GlasGrid®. Lay GlasGrid® over iron works, roll, and then cut using a sharp utility knife.
GlasGrid® must be applied without ripples. Sufficient tension during application will eliminate this problem.
Overlap at end of roll joints 75-150 mm (3”-6”).Ensure that the overlap are shingled in the direction of paving. Overlap longitudinal joints 25-50 mm (1” -2”)
Prior to paving, only construction and emergency vehicles shall be allowed to drive on installed GlasGrid®.