Cold-mix asphalt glue (binder)   Special colored topcoat for cold-mix asphalt

System description: Cold- colored permeable asphalt (polyurethane cold-lay asphalt) consists of two core materials: cold-mix asphalt glue (two-component polyurethane binder) is the material that bonds the aggregates to the skeleton; the colored topcoat is the surface protection, color-locking, and weather-resistant finish applied after completion. Used together, they are widely applied to greenways, trails, park paths, and landscape permeable pavements. The entire process is carried out at ambient temperature without the need to heat the asphalt.

I. Cold-mix asphalt gluecold-mix binder/polyurethane cold-lay glue) The mainstream is the A and B two-component polyurethane system.

(I) Core functions

1. B crushed stone aggregates to form the main structure of the permeable pavement. After curing, the glue wraps each basalt/granite aggregate, forming 18%~25% interconnected pores through point bonding, allowing rainwater to infiltrate rapidly and achieve the permeability function; it replaces traditional hot asphalt and cures at ambient temperature.

2. Flexible and crack-resistant adapting to ground deformation. It possesses elasticity after curing, which can offset cracks caused by slight settlement of the base layer and thermal expansion/contraction. It does not crack, lose stones, loosen under freeze-thaw cycles in the north or high-temperature exposure in the south; it is resistant to water immersion, acids, alkalis, and rainwater erosion. 3. Comes with a base color, and the glue itself can be mixed with colors (red, yellow, green, blue, gray) and blended with the stones. The color the pavement is consistent inside and out, unlike black hot asphalt which is only colored on the surface; it does not easily fade or turn white outdoors.

4. Low construction, operable in all four seasons at temperatures above 5°C. It requires no large mixing stations or asphalt heating equipment; small mixers and manual labor can be used for construction, small-area repairs extremely convenient; it cures quickly after spreading, allowing foot traffic in a short time.

5. Enhances the anti-slip and wear-resistant performance the pavement. The aggregates are firmly bonded, and it does not produce sand or drop particles under long-term pedestrian traffic. It has a high anti-slip coefficient, making it for pedestrian landscape pavements.

(II) Standard Application Method (Full Mixing   Spreading Steps)

1. Basic Raw Material - Aggregate: 3~5mm single-size basalt crushed stone, must be dry and free of mud and dust. Wet stones will cause the glue to fail to cure and to fail; - Glue: Two-component A (resin)   B (hardener); - Base: Cement concrete/compacted crushed stone base, level and firm, free standing water and oil stains.

2. Conventional Mixing Ratio (Industry Standard) Stone : Mixed Glue = 15~20 : 1 (by weight) - Pedestrianway (Standard): 18:1; - Wear-resistant/Residential Light Traffic: 15:1 (more glue results in higher strength and slightly lower permeability); much glue will clog the permeable pores and cause oil seepage on the surface; too little will result in loose aggregate and particle loss. 3. Mixing Sequence (Strictly Prohibited Reverse) 1. Pour A and B glue into a bucket according to the ratio, mix evenly with an electric mixer for 2 minutes and set aside; 2. Pour stones into the mixer and dry mix for 15 seconds; 3. Pour the mixed glue in 2~3 batches and continue mixing for 3~5 minutes; Qualified State: Every stone surface is evenly coated with a thin layer of glue, with no excess glue flowing and no dry material patches.

3. Spreading, Compaction, Forming 1. The mixed material must be spread within 30 minutes (the glue starts to cure, and exceeding this time will prevent proper compaction and bonding); 2. manually with a straightedge, controlling the spreading thickness: 4cm for pedestrian walkways, 6~8cm for light traffic; 3. Use a hand-held discel to lightly compact and smooth the surface, do not over-compact (over-compaction will squeeze the glue and clog the permeable pores); 4. Expansion Joints: Cut expansion joint every 4~5 meters to prevent cracking from thermal expansion and contraction. 5. Curing and Opening Time (Room Temperature 25°C) - ~6 hours: Surface dry, no walking allowed; - 24 hours: Fully cured, normal pedestrian traffic allowed; - 7 days: Mechanical strength fully meets standards, nonmotorized vehicles allowed. 6. Prohibitions Rainy days, air humidity >85%, and temperature <5°C are prohibited for construction; wet stones must absolutely not be mixed the mixed glue cannot be diluted with water.

II. Cold-Mixed Asphalt Colored Topcoat (Two-Component Polyurethane Weatherproof Topcoat)

(I) Core Functions (The final step of the pavement completion) 1. Lock in the overall color, completely prevent fading and UV yellowing. Seal the surface pores of the permeable pavement, isolate it from sunlight acid rain, and snow erosion, firmly lock in the original color of the glue, and significantly extend the outdoor service life; without a topcoat, it will darken, turn white, fade within 1~2 years. 2. Reinforce surface aggregate, prevent particle loss and sanding. Penetrate the gaps of the surface aggregate to re-bond loose surface, ensuring no gravel falls off during walking friction, and improving overall wear resistance. 3. Waterproof and Stain-resistant, Easy Daily Cleaning. Form a breathable protective film (without internal permeable channels, remaining permeable), preventing mud, water, and oil stains from penetrating, making it easy to clean with a daily water rinse; inhibit the pavement from turning white due efflorescence. 4. Correct Color Differences, Enhance Appearance. Unify the color depth differences of the pavement, available in matte and glossy finishes; matte is warm and antique, is transparent and bright; colored topcoats can also be chosen to deepen the pavement tone. 5. Freeze-Thaw and De-icing Agent Corrosion Resistance. In northern winters it will not be corroded or peel when de-icing agents are applied, and the paint film will not crack or peel off in high and low temperature environments

(II) Application Method and Construction Specifications

1. Pre-construction Conditions (Critical): Cold-mix asphalt pavement must be fully cured more than 7 days, the ground must be completely dry, free of moisture, floating dust, and debris; construction is only permitted when the temperature is 5~35°C without rain or snow, and humidity is ≤85%.

2. Dosage and Application Passes: Total dosage: 0.25~0.35kg/㎡ applied in two passes. First pass: thin spray for priming, penetration, and sealing; dry for 60~90 minutes; - Second pass: spray evenly in a direction, ensuring a full and uniform paint film.

3. Application Methods: Preferred: High-pressure airless sprayer (sprays evenly into permeable pores, best effect); Small: Roll horizontally and vertically with a long-hair roller; Single-component topcoat: stir well after opening and use directly; Two-component: mix according to the manufacturer' ratio, and use within 40 minutes after mixing.

4. Curing and Traffic Time: - 4 hours after spraying: surface dry, touching and stepping are prohibited; 24 hours: paint film fully dry, normal pedestrian traffic allowed; - 7 days: paint film completely cured, non-motorized vehicles allowed.

5. Classification Selection 1. Transparent weather-resistant type (most common): retains original colors, only provides protection and color fixation; 2. Colored color-changing type: renovates and changes after pavement fading, or deepens the color; 3. Matte type: preferred for landscape paths, non-reflective with a soft texture; Glossy type: brightens andifies plazas and main roads in parks.

## III. Complete Construction Process for Cold-Mix Asphalt

Base cleaning and reinforcement → Mixing dry stones with two-component cold-mix → Spreading, leveling, and light compaction for finishing → Cutting expansion joints → Curing at ambient temperature for 7 days until dry → Two-pass spraying of colored topcoat Open to traffic after curing is complete.