Experimental evaluation of the basalt fibers and diatomite powder compound on enhanced fatigue life and tensile strength of hot mix asphalt at low temperatures

In the present research, a composite of basalt fibers and diatomite was used to enhance fatigue life and tensile strength of hot mix asphalt (HMA). Conducted experiments included a four-point bending beam tests at 20 degrees C for determining the fatigue life of the mix, and indirect tensile strength test at - 5 degrees C for determining tensile strength and ultimate strain of the mixture. The results indicate that, in general, at higher levels of strain, fibers may not enhance fatigue life of asphalt mixes. Although a composite of basalt had not been effective in enhancing the fatigue life, the results indicate that the use of the fibers in reinforced mixes with diatomite (which were of higher stiffness) ended up with doubling the fatigue life. Investigating the results of indirect tensile tests at -5 degrees C and looking into the range of strain at failure, it is found that the basalt fibers can significantly improve the properties of hot mix asphalt at low temperatures, and simultaneous use of diatomite and basalt fibers can well compensate for weaknesses of asphalt mixes at lower temperatures. (C) 2017 Elsevier Ltd. All rights reserved.