Automobile Exhaust-Purifying Performance of Tourmaline-Modified Asphalt Concrete

摘要

This study investigated the purifying effect of tourmaline-modified asphalt on automobile exhaust. Six types of tourmaline-modi-fied asphalt concrete were prepared, aiming to achieving excellent exhaust-purifying performance. The purifying effect of tourmaline-modi-fied asphalt slabs on automobile exhaust was emulated indoors through using an exhaust-gas analyzer and a self-made air purifier chamber in the cooling process of the specimens. Then, the influence of laws of the cooling rate of the slabs, dosage of tourmaline, types of tourmaline, and method of tourmaline being added upon the purifying performance were studied systematically. The mechanism of purifying performance of tourmaline-modified asphalt concrete was analyzed through a thermoelectric property test. Finally, the road performance of tourma-line-modified asphalt concrete was evaluated through a relative performance test. The results show that tourmaline-modified asphalt concrete has a good purifying effect on automobile exhaust, especially on NO_x (nitrogen oxide compounds), where the maximum purifying rate can reach 93.1%. The purifying effect of tourmaline-modified asphalt concrete on automobile exhaust is improved by the increase of cooling amplitude and dosage of tourmaline. Purification effects of asphalt concrete with tourmaline anion powder on exhaust was improved with an increase in anion emissions; however, the purifying effect of tourmaline-modified asphalt on NO_x tends to decline with the increasing fineness of tourmaline. Thermoelectric test results show that the thermoelectric property of tourmaline can still perform well when it is added to asphalt. The high-temperature performance, low-temperature performance, and water-resistance performance of asphalt concrete could be improved clearly by using a tourmaline additive.