Investigation of Laboratory Test Methods to Determine Curing Rate of Asphalt Emulsion (Revised).

摘要

The study resulted from reports of emulsions used in the construction of chip seals taking an excessively long time to cure. This led to shelling of the stone from the pavement within a few hours or even days after construction. These failures were often attributed to the emulsion formulation even though the material passed all specifications. The objective of the study was to develop a test method which would identify the curing time of asphalt emulsions ensuring better field performance. Several test methods were investigated which led to the development of the TTI Cohesion test. The concept for the test was derived from an existing test used for determining the cure time for slurry seals. Results from laboratory testing indicated that the TTI Cohesion Test can be used to monitor the curing process of asphalt emulsion chip seal samples. Two parameters taken from the Cohesion Test may be used as qualitative indicators of the curing process of asphalt emulsion chip seals. The parameters are called Curing Index and T95. The Curing Index is the percentage of the total cure that has occurred at six hours. Rapid-setting emulsion laboratory chip seal should have Curing Indices of 75 or more. In other words, in six hours, a rapid-setting emulsion laboratory chip seal should have rea