1. What Is Sand Fog Seal?

Sand fog seal is a preventive maintenance technology that mixes an asphalt-based concentrated sealer produced by a special emulsifying process with additives, anti-wear aggregate (sand) and water, then sprays it through a high-pressure vehicle (or small spray/brush equipment) onto the asphalt surface to form a protective layer about 10 mm thick. Its service life is typically 2–3 years.

Because fine sand is already wrapped in the emulsion and sprayed in one pass, the separate steps of spreading sand afterwards and rolling with a rubber tire are eliminated, while the fully coated aggregate preserves skid resistance—a key advantage over plain fog seal.

2. Why Water-Based Epoxy Emulsified Asphalt + Basalt Sand?

2.1 Binder: water-based epoxy emulsified asphalt

After curing, water-based epoxy emulsified asphalt shows almost no plasticity at high temperature and resists rutting far better than conventional SBS/SBR modified emulsion. Typical targets: Brookfield viscosity 2000–8000 CPs, solids content ≥40%, 1-day storage stability ≤1%.

2.2 Fine aggregate: basalt

The sand particle size should be ≤2.36 mm (about 40–70 mesh), added at 15%–30%. Pull-off tests show basalt bonds to the epoxy emulsion far better than limestone, with a representative pull-off strength of about 3.54 MPa, so clean, dry, angular refined quartz sand or quality basalt sand is preferred.

3. Adhesion: Why Abrasive Blasting Matters

Pull-off tests on laboratory slabs show that abrasive-blasted slabs bond to the epoxy emulsion at about 1.96 MPa with only 3% variation, while un-treated slabs reach just 1.44 MPa with 14% variation. Abrasive blasting exposes the coarse aggregate surface, greatly improving inter-layer bonding and making construction quality consistent.

4. Six-Step Construction Process

1. Clean the pavement — blow, brush or pressure-wash away debris, especially oil and mud.
2. Abrasive-blast the surface — grind until coarse aggregate is exposed to strengthen inter-layer bonding.
3. Prepare equipment & materials — load and mix material before entering the work zone to prevent sand settling.
4. Spray the seal — high-pressure equipment at 3–5 km/h; single layer 0.9–1.2 kg/m², double layer 1.6–2.0 kg/m².
5. Touch up locally — hand-fix missed or over-sprayed areas for uniform coverage.
6. Cure — allow about 4 hours to dry and cure before opening to traffic.

5. Performance & Acceptance

Sand fog seal delivers: skid resistance, waterproofing (sealing hairline cracks and stopping water seepage), anti-aging (a barrier against oxidation and UV that locks oils in the binder and restores flexibility), durability (resists de-icing salts and oil stains), and environmental safety—a water-based sealer with VOC under 150 g/L, cold applied, non-flammable and non-toxic. Acceptance compares before/after skid pendulum value, texture depth and water-seepage coefficient (seepage reduction ≥30%).

6. Applications

Suitable for waterproofing high-grade highways, trunk roads, bridge decks and tunnel pavements; treating fine cracks, raveling, light map-cracking and surface binder loss; and beautifying shoulders, airfield runways, taxiways and parking lots.