Full Depth Reclamation Quality Assurance

With FDR, like most paving projects, the primary goal is to produce a strong, durable base course from existing pavement materials that is ready to receive a wearing surface. Inspectors can help achieve this goal by ensuring that the process is in accordance with the contract documents as follows: 

Mix Design: Verify representative samples were obtained throughout the project and that a mix design(s) was performed by a qualified lab resulting in a mixture that meets or exceeds the contract documents.

Surface Preparation: Walk or drive the entire pavement section to be reclaimed for the day to ensure the surface has been properly prepared and that all pre-construction repairs have been performed. Ensure premilling, if required for grade control, was performed satisfactorily.

 Acceptable Weather: Measure the air and pavement temperature and check conditions for anticipated heavy rainfall and freezing weather to determine if construction can start/continue.

Traffic Control: Verify that the proper traffic control is in place to keep the traveling public safe during FDR construction.

Quality Equipment:

• Verify that the on-board stabilizing agent/additive system of the reclaimer is equipped with a meter capable of recording the rate of flow and total amount of each liquid being added to the stabilized material.
• Verify that nozzles and spray bars are working properly and are not plugged.
• Verify that the bulk spreader is properly calibrated and is capable of accurately dispensing the required quantity of dry stabilizing agent/additive.
• Verify that motor graders used have cross slope indicators and are in accordance with the contract documents.
• Verify that the reclaimer is pulverizing the material to the required width, depth and maximum size.
• For foamed asphalt, verify that the proper half-life and expansion ratio is being maintained.
• Check the reclaimed mixture for uniformity and homogeneity as it is discharged from the reclaimer.
• Verify that the compaction equipment is of the required type, number and size and that scrapers and spray bars are properly working.

 Quality Workmanship:

• Verify that the stabilizing agent is being mixed to the required depth.
• Verify that the blending/mixing of water and stabilizing agent is adequate to ensure a homogenous, consistent blend throughout the treatment section.
• Monitor the amount of water introduced to maintain the specified range of optimum moisture content.
• Verify that the reclaimed mixture is placed to the proper depth, grade and cross-slope. Verify that the width of reclaiming overlaps the previous pass by the required minimum amount.
• Check that longitudinal and transverse joints are properly constructed.
• For cementitious stabilizing agents, verify that maximum mixing and compaction time frames are maintained.
• Verify that a control strip was established to determine the compaction procedures.
• Verify that the rolling procedure established in the control strip is followed and that the compacted density is within the specified range. Reestablish the rolling pattern if the density of the reclaimed mat is not in compliance.
• Verify that the completed section is trimmed to the proper grade and cross-slope.

 Application Rates: Periodic checks should be made to verify that the amount of material being added to the reclaimed mixture is within allowable tolerances.

 Curing:

• Verify that the reclaimed mixture can support the anticipated loads and will not impair material curing before opening the reclaimed section to light traffic.
• Verify that the completed reclaimed mixture is properly cured.