I. Current Situation and Strategic Value of the Sand and Gravel Aggregate Industry
As a key raw material for global infrastructure construction, the annual consumption of sand and gravel aggregates reaches 40 billion tons, with the Chinese market accounting for 50% of the global total demand. Under the dual drive of the new urbanization construction and the rural revitalization strategy, China's sand and gravel aggregate industry is at a critical juncture of transformation and upgrading. As a core component of concrete (accounting for 60-75%), its quality directly affects the compressive strength (C30-C60), durability (carbonation depth ≤ 25mm), and engineering safety factor (≥ 1.5) of building structures.

II. Technical Decomposition of Factors Affecting Concrete Strength

Material gradation system
The ideal gradation should meet the ASTM C33 standard, with coarse aggregate (5-25mm) and fine aggregate (0.15-4.75mm) configured in a 2:1 ratio, and the void ratio controlled at 35%-40%. Actual engineering cases show that poor gradation can lead to a 15%-25% decrease in 28-day compressive strength.

Quality parameters of manufactured sand
High-quality manufactured sand should meet the GB/T 14684-2022 standard:

Stone powder content: ≤ 10% (for concrete below C60)

Crushing index: ≤ 25%

Fineness modulus: within the medium sand range of 2.3 to 3.0

Needle and flake-shaped particles: ≤ 15%

III. Industry Pain Points and Technological Innovation Paths
There are currently three major quality risks in the market:

Improper equipment selection: 30% of enterprises use non-standard equipment, resulting in a fluctuation of ±0.5 in fineness modulus.

Defects in process control: The phenomenon of stone powder content exceeding the standard by 2 to 3 times is widespread.

Lack of detection system: Only 45% of enterprises are equipped with online particle size analyzers.

Solution:
VSI vertical shaft impact sand making system. It innovatively adopts the dual-mode crushing principle:

Stone-on-stone mode: Achieving cubic shaping of 10-20mm aggregates (sphericity coefficient ≥ 0.7)

Stone-iron mode: Precise control of fine sand gradation within 0-5mm (passing rate deviation <5%)
The intelligent control system can adjust the rotational speed (1200-1800r/min) and feed rate (50-800t/h) in real time, keeping the fineness modulus of the finished sand stable within ±0.2 range.




IV. Intelligent Production Line System Integration Solution

Core equipment combination:

Primary crushing: Jaw crusher (feed particle size ≤ 1200mm)

Secondary crushing: Impact crusher/Cone crusher (Output size: 20-40mm)

Sand-making unit: VSI6X vertical shaft impact crusher (finished product 0-5mm)

Screening system: Three-axis elliptical vibrating screen (screening efficiency ≥ 90%)

Process optimization model:

Closed-loop circulation system: The return material ratio is controlled at 30% - 40%.

Dry dust removal technology: Dust concentration ≤ 10 mg/m³

Water treatment system: Achieving 95% water resource reuse




Our company offers full life-cycle solutions, covering process design (BIM modeling), equipment selection (CFD fluid simulation), intelligent operation and maintenance (IoT remote monitoring), and other links. Click on the official website for online consultation to obtain customized feasibility reports and economic analysis plans, and help build a green and intelligent sand and gravel aggregate production base.