Effect of soil clogging and water saturation on freeze-thraw durability of pervious concrete

The objective of this research was to evaluate the resistance of previous concrete to degradation during freeze-thaw cycling under different soil clogging and water saturation conditions. Laboratory testing of freeze–thaw durability involved two levels of soil clogging and two water saturation conditions in a full-factorial experimental design, and field testing involved measurements of stiffness and compressive strength on clogged and unclogged locations of an experimental pervious concrete slab placed in northern Utah. Both experimental factors and their interaction were determined to be statistically significant in this research. Specimens that were clogged with soil or completely submerged in water, or both, were damaged at a significantly faster rate than those specimens that remained unclogged and unsaturated. The average number of freeze-thaw cycles to failure was 93 for clogged specimens compared with 180 for unclogged specimens, and 80 for saturated specimens compared with 193 for unsaturated specimens. A comparison of in situ modulus values, core modulus values, and core compressive strengths associated with clogged locations and unclogged locations in the experimental slab indicated no significant differences in structural properties in the clogged and unclogged locations. That was likely attributable to the fact that only the upper 1 to 2 in. of previous concrete in clogged locations was filled with debris. The remaining depth of the slab seemed to be free draining. These research findings emphasize the importance of ensuring that previous concrete remains free of debris and well-drained during service in cold regions