Asphalt concrete is artificial matching a certain gradation composition of mineral aggregate (crushed stone or crushed gravel, stone chips or sand, slag, etc.) with a proportion of road bituminous materials,Road Router Crack under strictly controlled conditions mixed.
Classify
Asphalt concrete used by the binder can be divided into two major categories of petroleum asphalt and coal tar pitch; some countries are also using or mixing of asphalt mixed with natural. Press aggregates used different varieties can be divided into gravel, gravel, sandy, several types of slag, crushed stone using the most common. Different maximum particle size of the mixture, can be divided into coarse (35 to 40 mm),lasting value concrete equipment manufacturer the granules (20-25 mm), fine particles (10 to 15 mm), sand (5-7 mm), etc. several categories. Press the compactness of the mix can be divided into dense graded, semi-open-graded and open-graded and several categories, open-graded asphalt mixes, also known as gravel. Wherein the thermal hot mix paved dense Macadam durable, high strength, good integrity, is the construction of the High Representative of asphalt pavement materials, the most widely used application.
Different countries have different asphalt concrete formulation of norms, the development of China's hot shop hot mix asphalt specification to porosity of 10% or less is called asphalt concrete, subdivided into type Ⅰ and type Ⅱ,Electronic Road Signage best cheap market Ⅰ type of porosity and was 3 (or 2) to 6%, is a dense-graded type; ⅱ type is 6 to 10%, is a semi-open-graded type; porosity of 10% or more are known as bitumen macadam, is open-graded type; mixed physical and mechanical properties of the material have stability, flow value and the porosity and so on.
Preparation technology
Hot mix asphalt mixture should be in a centralized location using a mechanical mixing. Generally used in stationary hot mix plant, longer should use mobile hot mix machine lines. Cold mix asphalt mixtures can concentrate mixing, it may also be mixed with the road. Major equipment asphalt plant include: Add hot asphalt, gravel storage place, slag warehouse, heated rollers, mixing machines and weighing equipment, steam boilers, pumps and piping bitumen,high performance epoxy power trowel dust and other facilities, as well as some hot aggregate re-sub-screen and storage equipment (see asphalt mixing base). Mixing machine can be divided into continuous and batch-type two categories. In the preparation process, after the first use of the past for aggregate drying, heated, with hot and cold asphalt mixing slag. Recently, they develop a wet marinated with hot asphalt aggregate, and then heating the mix of methods to eliminate the fly ash aggregate upon heating and drying. When using the latter process, to prevent residual moisture in the mix of asphalt concrete life, preferably while using asphalt anti-stripping agent to enhance water resistance.