According to different types of aggregates used, asphalt concrete can be divided into crushed stone, gravel, sandy and slag, and crushed stone is widely used. Do you know what to look for when choosing Jinan asphalt concrete?
The strength of asphalt concrete materials is mainly shown in two aspects. One is the cohesive force of the binder formed by asphalt and mineral powder; The other is the internal friction and locking force between aggregate particles. The huge surface area of fine mineral powder particles (mostly less than 0.075mm) makes asphalt material form a film, thus improving the adhesive strength and temperature stability of asphalt material; The locking force is mainly generated between coarse aggregate particles.
The mineral aggregate gradation of asphalt concrete shall be selected in consideration of both, so that the mixture can form a dense, stable, suitable roughness and durable pavement after adding an appropriate amount of asphalt. There are many methods for mixed mineral aggregate, which can be calculated by formula or the grading range can be specified by experience. The appropriate amount of asphalt in asphalt concrete materials shall be determined based on the laboratory test results and the practical situation of the construction site. Generally, the range of asphalt amount that can be referenced is listed in the relevant specifications as the guide for trial mixing.
Hot mixed asphalt concrete materials should be mixed mechanically at centralized locations. Generally, fixed hot mixing plants are selected, and mobile hot mixing machines should be selected when the line is long. Cold mixed asphalt concrete materials can be mixed in a centralized way or mixed on the road.
In terms of preparation technology, in the past, the sand and gravel materials were dried and heated before being mixed with hot asphalt and cold mineral powder. A method of mixing wet aggregate with hot asphalt first, and then heating and mixing is developed to eliminate fly ash caused by heating and drying of aggregate.
When using the latter process, it is necessary to prevent the residual moisture in the mixture from affecting the service life of asphalt concrete, so that asphalt anti stripping agent can be used at the same time to enhance the water resistance.
The above is the answer to the question that the selection of asphalt concrete depends on its properties and preparation process. If you have any questions about this, you can come to our website at any time http://www.ycgjglcl.com Consult and explain more matters to you!