The Future of Moisture Sensitivity Testing
U.S. Patents #8,020,451 – #6,799,471 – #8,312,776
M.i.S.T. (Moisture Induced Stress Tester) is designed as a totally new, quick and logical method for testing moisture damage susceptibility of asphalt mixtures. The M.i.S.T. is the latest innovation from InstroTek and unlike current test methods, is designed to simulate the stripping mechanisms that occur in HMA pavement layers.
For years, roadway engineers and asphalt contractors have been searching for a better method to test for “stripping” or “raveling,” which is the loss of bond or cohesion between aggregate and asphalt binder. Current test methods can take days to complete and are not conducive to a production quality control environment. Results also vary widely due to the lack of controls over the degree of saturation and temperature. More importantly, current test methods do not replicate the dynamics of pore pressure and scouring created in the field by vehicle tires passing over wet pavement.
The InstroTek, Inc. M.i.S.T. is a cyclic conditioning system that is designed to simulate the stripping mechanisms that occur in HMA pavement layers. The M.i.S.T. is a stand alone unit that consists of a pressurized chamber that pushes and pulls water through a compacted asphalt sample, simulating the action of an automobile tire on the road. The tests can be performed at different pressures and temperatures to replicate different traffic and environmental conditions. The unit is completely automatic and results are ready in as little as four hours. Simply place your asphalt core sample in the M.i.S.T. testing chamber, select your test parameters, press start and the unit does the rest. Upon completion of the test, the asphalt core is taken out of the testing chamber and evaluated for susceptibility to moisture damage.
- Designed to simulate HMA pavement stripping mechanisms.
- Shorter test times than current moisture sensitivity tests. Results in less than one day.
- Tests can be performed at realistic pressures similar to pressures produced by vehicle tires.
- Testing is automatic and monitored by sensors.
- Data can be stored and transferred to a PC for evaluation and archiving.