Laserfiche WebLink
Modified Boiling Test (Proposed by Research Team) <br />One half of the sample left over from the dry indirect tensile strength tests was used in the <br />modified Iowa boiling test. A total of four samples were tested, two that had the highest air <br />voids (14%) and two that had the lowest air voids (7%). These samples were weighed, placed in <br />a pot of boiling water for 6 minutes, allowed to cool and reach an air dried state and the final <br />weight was measured. Neither of the specimens showed any visual cues of stripping (asphalt <br />removed from aggregate particles) as the before test condition (Figure 2.12) looked similar to the <br />after test condition (Figure 2.13). <br />However, the specimens with 14% air voids lost an average of 12.2% of their initial <br />weight and the specimens with 7% air voids lost an average of 3.4% of their initial weight. In <br />addition, empirical observations after the test showed that the specimen with higher air voids was <br />much less intact than the comparable specimens with lower air voids (Note the distorted shape in <br />Figure 2.13). The 14% air void specimens crumbled after the test and had to be handled very <br />delicately and the 7% air void specimens were still intact and could be handled `normally'. <br />Figure 2.12. 7% and 14% Air Void Specimens (left and Right) before Modified Boiling Test <br />Figure 2.13. 7% and 14% Air Void Specimens (left and Right) after Modified Boiling Test <br />B-17 <br />