15 March 2001
DISTRESS 69, PUMPING
11.1. Description. Pumping is the ejection of material by water through joints or cracks caused
by deflection of the slab under passing loads. As the water is ejected, it carries particles of gravel,
sand, clay, or silt and results in a progressive loss of pavement support. Surface staining and
base or subgrade material on the pavement close to joints or cracks are evidence of pumping.
Pumping near joints indicates poor joint sealer and loss of support which will lead to cracking
under repeated loads. Deduct curves for pumping are shown in Figure 11.1.
11.2. Severity Levels. No degrees of severity are defined. It is sufficient to indicate that
pumping exists (Figures 11.2., 11.3., 11.4., and 11.5.).
11.3. How to Count. Slabs are counted as follows (see diagram): one pumping joint between
two slabs is counted as two slabs. However, if the remaining joints around the slab are also
pumping, one slab is added per additional pumping joint (Figure 11.6.).
11.4. Options for Repair. Seal cracks and joints; underseal.