Recently, three railways, including the Lobo to Ruoqiang Railway, 11 highways, including the project of the section of National Highway 320 from Huawu in Yuhang to Gaoqiao in Fuyang, and one airport project, the expansion of the flight area and work area of the Hefei Xinqiao International Airport, have received approvals one after another from the national/provincial/municipal Development and Reform Commissions, the Ministry of Natural Resources, and the provincial Department of Transportation and Communication, among other departments. The approvals include industrial feasibility, environmental impact report, preliminary design, construction land, project proposal, etc. The total project investment is about 96.6 billion RMB. According to relevant data estimates, the above 15 railway and highway projects approved or will bring more than 40 million tonnes of sand and gravel demand.

(Highway railway)

First, what are the requirements for sand and gravel suitable for railway and highway?

1. Particle size distribution: sand and gravel aggregates should have a reasonable particle size distribution, which means they should contain a variety of different particle sizes. This helps to form a solid structure, reduce porosity and improve densification.

2. Solidity: Aggregates should be strong enough and wear-resistant to resist the loads and pressures of vehicles and trains. Stronger aggregates reduce deformation and wear.

3. Physical stability: Aggregate should have good physical stability to prevent creep or settlement due to moisture and pressure.

(Mechanism sand and gravel)

4. Height Angle Internal Friction Angle: Aggregate should have sufficient height angle internal friction angle to ensure that it is less prone to slippage when travelling in vehicles.

5. Water Absorption: Aggregate should not be too absorbent as excessive water absorption may lead to icing, softening or other undesirable effects.

6. Durability: A quality aggregate should have good durability and be able to maintain its performance over long periods of time and under adverse conditions.

7. Non-corrosive: sand and gravel aggregates should not have corrosive properties to railway and highway materials and facilities to ensure the life and safety of railways and highways.

Second, how to produce railway, highway sand and gravel aggregate?

1. Raw material selection: first of all, you need to choose suitable raw materials, usually using high-quality natural stone, such as granite, limestone, basalt and so on. These stones should meet the relevant standards and requirements, such as hardness, firmness, wear resistance and so on.

2. Crushing and sand making: The raw materials are preliminarily crushed by jaw crusher, and then further crushed and sand making by cone crusher, impact crusher and other equipments to get the required grain size.

3. Screening: The crushed stone is graded by screening equipment to separate the stones with different grain sizes and get the sand and gravel aggregate that meets the requirements.

4. Washing: sometimes it is necessary to wash the sand and gravel aggregate to remove the dirt, dust and other impurities, and improve the cleanliness of the sand and gravel aggregate.

5. Quality testing: the quality of the produced sand and gravel aggregate is tested to ensure that it meets the relevant standards and requirements.

These 15 railway and highway projects involved in the region, sand and gravel enterprises can improve the sand and gravel production process, improve the quality of sand and gravel to fight for the competitiveness of the industry, and continue to contribute to the national infrastructure of their own strength.