A. General Descriptions
Chip seal to building waterproof tack coat on the concrete bridge surface is that chip sealer is applied to spread aggregates synchronously when sprays asphalt binders, so as to build a functional layer of strong cohesive property and shear property between the bridge concrete deck and asphalt coat to prevent water from leaking into the bridge deck.
Chip seal waterproof tack coat technology is a kind of effective solutions to treat waterproofing of cement concrete bridge deck. This technology can effectively prevent water from leaking into the bridge deck, and main girder and steel bars in the deck from rusting; the elastic and gelatinous thick asphalt deck embedding with chips can absorb stress between asphalt concrete coat and bridge deck to prevent asphalt concrete coat from shearing and deformation.

B. Technical features
a. Chip seal layer as waterproof tack coat can effectively stop water from leaking into the concrete bridge deck, and main grinder and steel bars in the deck from rusting, as well absorb stress between asphalt concrete coat and bridge deck to prevent asphalt concrete coat from shearing and deformation.
b. As a transition functional layer, chip seal layer binds two different layers in modulus (asphalt concrete coat and bridge deck) as a unit to improve the stress loading capability between bridge deck and asphalt coat, and bring the compounding function of asphalt coat and bridge deck into full play.
c. When the bridge deck performs horizontal deformation caused by temperature changes and traffic loads, the waterproof tack coat will absorb the horizontal shear stress and flexural-tensile stress between asphalt coat and bridge deck.
d. Waterproof coat construction on the bridge applies chip seal technology to make construction faster and easier and higher automation.
e. Compared to the waterproof tack coat of paint film and coils, chip seal tack coat gives better performance in construction operability and costs reduction.
C. Materials and construction equipments
a. The required materials mainly include modified asphalt or asphalt rubber and other asphalt, and aggregates satisfying the gradation specifications.
b. It requires aggregates gradation machine, milling machine, shot blaster, road brusher, chip sealer and tier roller.

D. Process flows
Preparations → Construction areas close to traffic and cleaning → Spray tack coat →  Chip seal → Rolling → Pavement preserving and cleaning

E. Project cases
Meng Beng Expressway
Wu Ma Expressway
Huang Ta Tao Expressway
Round-Yangzhou Expressway
Chang Cheng Expressway
Huai’an Bridge in Ning Huai Expressway
Huanghe Bridge in Binzhou
Ping Zhong Expressway
The Third Bridge over the Qianjiang River
Yanjiang Expressway