Asphalt driveway structure and type

The structural composition of asphalt driveway

1. The structural layer of asphalt driveway can be composed of surface layer, grass-roots level, sub-base layer and bedding layer.

2. The surface layer is directly subject to repeated wheel loads and natural factors affecting the structure of the layer, can be composed of 1 to 3 layers. Surface layer should be set according to the applicable requirements of anti-skid wear-resistant, dense and stable asphalt layer; in the surface layer, the following layer should be based on the highway grade, asphalt layer thickness, climatic conditions, such as selecting the appropriate asphalt structural layer.

3. Grass-roots level is set under the surface layer, and the opposite layer together with the repeated action of the wheel load spread to the bottom of the grass-roots level, bedding, soil base, the main load-bearing role of the level. The strength index of the base material should have high requirements. According to the highway grade or traffic volume needs to be set up one layer or two layers of grass-roots level. When the grass-roots level is thicker and needs to be divided into two layers of construction, it can be called the upper base layer and lower base layer respectively.

4. The base layer is set under the grass-roots level, and with the surface layer, the grass-roots level together to bear the repeated action of the wheel load, and play a secondary load-bearing role of the level. The strength index requirement of sub-base material can be slightly lower than that of base material. The sub-base can be set up in one layer or two layers according to the needs of highway grade or traffic volume. Subgrade thicker need to be divided into two layers of construction, respectively, can be called on the bottom of the base, the bottom of the base.

5. bedding is set in the sub-base and soil base between the structural layer, drainage, waterproof, frost, pollution prevention and other functions.

Asphalt driveway classification

(1) according to the technical quality and use of classification

1. Asphalt concrete pavement: by the appropriate proportion of various different sizes of aggregates, mineral powder and asphalt, heated to a certain temperature and then mixed, paved and compacted into the pavement surface. Asphalt concrete pavement is suitable for all levels of highway surface.

2. asphalt crushed stone pavement: asphalt crushed stone for the surface of the road surface

3. asphalt penetration: asphalt penetration into the crushed (gravel) stone for the surface of the road, that is, the asphalt poured in the paved main layer of aggregate, and then layered with embedded stone chips and pouring asphalt, layered compaction, the formation of a dense asphalt structural layer.

4. Asphalt surface treatment: asphalt and aggregate according to layer paving method or mixing method of paving and become the thickness of not more than 3cm of asphalt surface layer, surface treatment according to the pouring of asphalt and spreading of aggregates in different traverses, is divided into single-layer, double-layer type, three-layer type.

(2) according to the composition of structural classification

1、Dense-suspension structure

2、Skeleton - void structure

3、Dense-skeleton structure

(3) according to the mineral grade classification

1. Dense graded asphalt concrete mixture

2. Semi-open graded asphalt mixture

3. Open-graded asphalt mixture

4. Intermittent graded asphalt mixture

(4) according to the mineral material particle size classification

1.gravel asphalt mixture: the maximum particle size of the mineral material is equal to or less than 4.75mm (5mm round hole sieve) of asphalt mixture. Also known as asphalt chips or asphalt sand.

2. Fine-grained asphalt mixture: the maximum particle size of the mineral material for 9.5mm or 13.2mm (round hole sieve 10mm or 15mm) of the asphalt mixture.

3. Medium-grained asphalt mixture: the maximum size of the mineral material 16mm or 19mm (round hole sieve 20mm or 25mm) of asphalt mixture.

4. Coarse-grained asphalt mixture: the maximum size of the mineral material 26.5mm or 31.5mm (round hole sieve 30 ~ 40mm) of asphalt mixture.

5. Special coarse-grained asphalt mixture: the maximum size of the mineral material is equal to or greater than 37.5mm (round hole sieve 45mm) of asphalt mixture.

(5) according to the construction temperature classification

1 hot mix hot paving asphalt mixture: asphalt and mineral materials after heating and mixing, and in a certain stability to complete the paving and rolling construction process of the mixture

2. Normal temperature asphalt mixture: the use of emulsified asphalt or diluted asphalt at room temperature (or heating temperature is very low) and mineral mix, and at room temperature to complete the paving and rolling process of the mixture.