沥青混合料对水环境的影响

Effect of Asphalt Mixture on Water Environment

摘要:

为了研究与沥青混合料接触后水质的变化，首先在实验室内成型了10组沥青混合料的马歇尔试件，成型试件时考虑了不同的沥青混合料级配、空隙率和沥青标号，以及添加抗剥落剂等因素，并把试件放入不同pH值的水样中真空饱水24h；然后按照中国生活饮用水评价指标，测试了真空饱水后水样的pH值、耗氧量、总硬度及重金属含量.结果表明：沥青混合料真空饱水24h后，水质恶化明显，中性水样pH值约增大04倍，酸性水样pH值则增大17倍以上，在沥青混合料中添加抗剥落剂以及降低沥青混合料的空隙率可以有效降低水样pH值的增大幅度；水样的化学耗氧量增大3~4倍，通过降低沥青混合料空隙率、适当提高初始水样的pH值至中性等方式，可以降低水样中有机物的含量；水样的总硬度增大3~4倍，在沥青混合料中添加抗剥落剂可降低水样总硬度的增大幅度.

Abstract:

In order to study the water quality after the interaction with asphalt mixture, ten groups of Marshall samples of asphalt mixture with different air void percentages, gradations, asphalt grades and anti stripping agent were prepared firstly. Water samples with different pH values were also prepared in laboratory. Then, the asphalt mixture samples were immersed in the vacuum sealing water for 24h. Some indices including pH value, oxygen demand, total hardness, content of heavy metals were selected from the standards for drinking water quality to evaluate the water quality after its contact with asphalt mixture. Results show that water quality is deteriorated significantly when asphalt mixture is immersed in the water samples for 24h. pH values of neutral and acid water samples are 04 times and 17 times that before immersion test respectively. The increase of pH values can be reduced by anti stripping agent and lower air voids of asphalt mixture. After immersion test, oxygen demand and total hardness of water sample are increased over 3 to 4 times. Lower air voids of asphalt mixture and increasing pH value of initial water sample to neutral condition can reduce the oxygen demand. The increase of total hardness can be retarded by using anti stripping agent in asphalt mixture.