Hot In Place Recycling Best Practices

If an unrolled HIR mix is caught in a heavy rainstorm, it can be compacted to support temporary traffic. However, the mat will probably not achieve the proper density. The mat can be reworked and compacted when dry conditions allow. 

For best results, ambient temperatures should be 45-50 ^oF (7-10 ^oC) and rising before starting HIR.

White smoke is steam leaving the pavement. Excessive blue smoke is an indication of overheating the pavement.

Excessive broken aggregate is an indication of insufficient pavement temperature prior to scarification/augering/milling.

Cores should be checked for the presence of paving fabrics and should be at least 1 inch below the anticipated HIR depth.

Excessive broken aggregate is an indication of insufficient pavement temperature prior to scarification/augering/milling

If an unrolled HIR mix is caught in a heavy rainstorm, it can be compacted to support temporary traffic. However, the mat will probably not achieve the proper density. The mat can be reworked and compacted when dry conditions allow. 

Temperature monitoring should take place between all preheaters to ensure proper heating prior to recycling.