Asphalt Road Construction Process – Preparing Materials for Asphalt Concrete Mixing
- Material Selection and Testing:
- Choose materials and test their physical and mechanical properties to ensure they meet requirements.
- Design the aggregate gradation in the cold bin.
- Perform trial mixes of the designed aggregate gradation at the mixing plant.
- Sample the aggregates from the hot bin.
- Analyze the particle size distribution of the aggregate samples and adjust the gradation in the cold bin if needed.
- Estimate the asphalt content roughly (within 0.3 – 0.5% deviation).
- Prepare asphalt concrete test samples in the laboratory.
- Test the physical and mechanical properties of the asphalt concrete samples.
- Present the test results to the project supervisor and propose a suitable asphalt content for the asphalt concrete.
- Trial Section Construction (minimum 80 tons of asphalt concrete):
- Conduct after receiving the project supervisor’s acceptance letter for the asphalt concrete mix design.
- Submit the trial section construction design documents to the project supervisor.
- Prepare the mixing plant, construction machinery, and testing equipment.
- Mix the asphalt concrete and check its quality at the mixing plant.
- Transport, lay, and compact the asphalt concrete according to the trial section construction design; record relevant data such as the temperature of the asphalt concrete when leaving the mixing plant, during laying, and compaction; subgrade elevation before laying asphalt concrete; final road surface elevation after compaction; number of compaction passes and roller speeds.
- After 24 hours, core samples of the asphalt concrete at the site to determine the density and thickness of the asphalt concrete after compaction in various sections.
- Develop the large-scale construction technology and submit it for approval by the project supervisor and investor.
