摘要: |
Density of cores that are cut from the roadway following compaction on new pavements in CT is used as a quality indicator. This density needs to be determined accurately as it impacts payment. Cores need to contain material from the placed surface without mix adhering to underlying layers in order to be determined accurately. In addition, when cut cores do not have a smooth bottom surface, density may not be able to be determined accurately. More than 1,100 cores from the 2012 and 2013 construction season were collected and analyzed to determine what level of surface relief (or texture depth) would affect accurate measurement, and thus require saw cutting. It was determined that when more than 4.5 mm of surface relief exists on the bottom of a core it should be saw cut to a planar condition to avoid density measurement errors. A gauge was developed at the University of Connecticut to measure texture depth when it is not readily evident that it is greater than 4.5 mm. Recommendations include saw cutting core bottoms to remove underlying material attached to the pavement to be tested, as well as when surface relief is in excess of 4.5 mm. It is further recommended that cores containing less than 4.5 mm of surface relief and having no underlying material attached be measured in their existing condition because there is no benefit gained when saw cutting these cores. |