Investigation of Joint Deterioration in MnROAD Phase 1 Jointed Concrete Pavement Test Sections

Status: Complete
Report Date: 04/26/2010

Summary:

A comprehensive forensic investigation was conducted at MnROAD in 2008. This investigation focused principally on joint performance, as little panel cracking had occurred. The most interesting observation was a unique distress phenomenon in the transverse joints. This distress occurred where jointed concrete pavements were built on undrained gravel bases. Cores showed that a significant amount of concrete material was missing from the middle section of the joint, with the area of greatest distress just below the saw cut, approximately at mid-depth. To determine whether this distress was unique to MnROAD test sections, six other Minnesota concrete pavement projects, of similar age and materials, were examined. While similar types of distress were found, the extent of the damage was not as severe. This may be due to much less traffic loadings being applied to those sections compared to MnROAD. In all cases, though, sections with base layers that adequately drained water within the joints performed significantly better. A discussion of the potential causes of the distress revealed that it is likely a combination of freeze/thaw damage and erosion due to fast-traveling trucks that ultimately caused the distress. Findings show: High Volume Traffic - Undrained PCC on Class 5 base has resulted in significant joint distress (regardless of seal condition) - Drained PCC on Class 5 base with edge drains and well sealed joints performed better than undrained PCC - The combination of drainable base layers and edge drains worked best Low Volume Traffic - Undrained PCC on Class 5 base with well sealed joints performed excellently - Undrained PCC on Class 5 base with poorly sealed joints exhibits significant distress

Final Deliverables:

Report #2010-18