Water Bleeding and Pumping

Description

Water bleeding (left two photos) occurs when water seeps out of joints or cracks or through an excessively porous HMA layer. Pumping (right-most photo) occurs when water and fine material is ejected from underlying layers through cracks in the HMA layer under moving loads.

Figure 1: Water bleeding.

Figure 2: Water bleeding up close.

Figure 3: CTB base pumping.

Problem

Decreased skid resistance, an indication of high pavement porosity (water bleeding), decreased structural support (pumping)

Possible Causes

Several including:

• Porous pavement as a result of inadequate compaction during construction or poor mix design
• High water table
• Poor drainage

Repair

Water bleeding or pumping should be investigated to determine the root cause. If the problem is a high water table or poor drainage, subgrade drainage should be improved. If the problem is a porous mix (in the case of water bleeding) a fog seal or slurry seal may be applied to limit water infiltration.