Production process of recycled concrete:
-    Source of raw materials: To create a source of raw materials for the production of concrete from construction material waste, the Project Development Board has established a "team to collect" construction material waste from demolition works. : Apartments, offices, private houses... Raw materials are collected and transported to the factory's storage yard (at the Company's quarry). Here, I have classified concrete blocks (construction material waste) by size, concrete blocks larger than 800mm (or smaller than 800mm but with iron and steel structure in concrete) will be "damped" by the vehicle into smaller concrete blocks. At this stage, iron, steel, zinc ... in the concrete block will be removed. After sorting, the raw concrete will be fed to the stone crusher through the first screening vibrating conveyor belt to separate the soil and sand. The remaining concrete will be put into the crusher.
-    Coarse crushing stage: I used a 350 ton/hour stone crusher available at the mine to coarsely grind these raw concrete blocks. Working principle of coarse crusher: Under the motor wheel, the "rotary wheel" will rotate the concrete block at high speed, taking advantage of the centrifugal force to throw the concrete into the grinding gear, the debris continuously collides with Gears, grains of sand, and gravel fall out of the concrete block, making them smaller in size. Sand, gravel, stone and other substances contained in the concrete will be mechanically separated from the original concrete block because they are actually only physically bound together, there is no chemical reaction in the concrete. concrete texture.
-    Recovery of aggregate stone: After the materials are separated from the grinding mill system, they will be transferred to the sieve conveyor. This process will screen a second time and remove impurities, stones and sand from the crushed concrete. This stage produces coarse aggregate which is concrete stone with size from 01 to 4 cm, replacing construction stone of the same size taken from quarry and other products such as sand, stone powder...
-    Create Concrete: Aggregates from recycled concrete are mixed in certain proportions with sand, cement, and water to produce finished concrete. Depending on the requirements of the market, it is possible to produce different products, concrete max 100, concrete pavement, concrete pavement ...

Testing the Company's Recycled Concrete: To ensure the quality of the Company's products, I directed the Technical Department to take the product for inspection. And, the results are very positive:
Parameters of tested recycled concrete products:
- Compressive strength: 50-65 MPa
- Strength of splitting: 2.7-3.8 MPa
- Static elastic modulus: 23-36 GPa
- Abrasion: <0.3g/cm2
- Water absorption: <6%
- Chlorine ion permeability: Low
- Dry shrinkage: <0.07%
- Volumetric weight: 2.1-2.3g/cm3
- No potential for aggregate alkali reaction
Through experimental and practical results: The production of recycled concrete used in low-stress structures such as eels, sidewalks, concrete linings, panels, vertical walls in the drainage ditch system, chairs ice… is very reasonable and safe.

Socio-economic efficiency:
- Using aggregate stone from recycled concrete is eco-friendly, this is the most important advantage of this green material. The process of quarrying and then crushing requires the use of natural resources and mechanical processing. The recycling of concrete will create a new life cycle for the aggregate, will significantly reduce the amount of sand, gravel and stone extracted from nature, save natural resources, do not affect the ecological environment, and do not cause pollution. environmental pollution in the mining area.
- The process of recycling concrete from construction material waste (concrete shreds, construction waste, etc.) also significantly reduces the amount of waste dumped into local landfills. For many years, local authorities in Binh Duong province have had to deal with the problem of overcrowding in landfills or the dumping of construction waste everywhere. In addition to occupying large spaces at landfills, construction waste is also difficult to biodegrade. The recycling and reuse of construction waste helps save costs in disposal at landfills.
This is a practical study by the Project Development Board that I have done. The project creates low-cost products but also solves the problem of waste in construction, and at the same time brings high economic efficiency.

NGO THANH TUNG