摘要: |
Moisture damage limits the life of hot mix asphalt (HMA) pavements. In Wisconsin, igneous aggregates are particularly sensitive to moisture damage. There are various tests to quantify potential moisture damage in HMA mixtures, which include tensile strength ratio (TSR), Hamburg wheel, visual strip rating and others. There is no agreement on how these various tests assess the probability that moisture damage will occur. Therefore, there is a need to identify mix test results that actually correspond to in-place damage. Pavements found in Wisconsin projects that have moisture damage will be evaluated by recreating the pavements mixes and performing a battery of tests to predict moisture sensitivity. While different aggregates in mixture should be tested, mixture with aggregates known to be susceptible to moisture damage will be targeted. Aggregates that are not susceptible to moisture damage should also be evaluated.
The objective of the study is to develop recommendations regarding moisture sensitivity testing that targets mixes that have a history of concern.
The objective of the study will be addressed by: (1) Assessing projects where moisture damage has appeared to take place. (2) Targeting aggregates for which there is a concern for moisture damage or loss of adhesion of the asphalt binder to the aggregate. (3) Recreating mix designs and running a suite of applicable moisture sensitivity tests. (4) Rerun tests with an anti-strip additive to determine effectiveness. (5) Reviewing and recommending changes to specifications to reduce risk of moisture damage. |