Durability is a prerequisite for satisfactory performance of concrete pavements in freeze-thaw environments. The Kansas Department of Transportation (KDOT) has been experiencing durability problems of limestone aggregates since the 1930s and, finally, has developed stringent specifications for concrete aggregates through a series of field and laboratory studies in the mid-1980s. Recently, pavements that potentially are nondurable because of contamination of limestone aggregates have been detected on three projects on I-35 and US-50. These projects involved more than 500,000 yd2 of concrete pavement, worth approximately $10,000,000. The suspected contamination was first detected by a geological investigation on slices of cores and beam samples randomly taken from the project as well as on loose coarse aggregate samples larger than 4.75 mm (U.S. No. 4) sieve size. Freeze-thaw tests (ASTM C-666; Procedure B) on the cores and beams retrieved from these projects indicated that the samples with higher percentages of aggregate contamination did not meet the KDOT specifications for durable concrete. Results of ASTM C-666 (Procedure B) tests on the beam samples prepared with increasing percentages of nondurable aggregate (contaminant) show that higher expansion and lower durability correlate very well with the increasing percentage of contaminants. An analysis of service life adjustments made because of the ranges of contamination detected in the project cores indicates a reduced service life of 5.1 percent for the I-35 concrete pavement and 5.5 percent for the concrete pavement placed on US-50.
Microstructure-guided numerical simulation to evaluate the influence of phase change materials (PCMs) on the freeze-thaw response of concrete pavements
