SINTEF Building and Infrastructure, Norway.
Sci Total Environ. 2012 Jun 15;427-428:86-97. doi: 10.1016/j.scitotenv.2012.04.021. Epub 2012 May 2.
The release of major and trace elements from recycled concrete aggregates used in an asphalt covered road sub-base has been monitored for more than 4 years. A similar test field without an asphalt cover, directly exposed to air and rain, and an asphalt covered reference field with natural aggregates in the sub-base were also included in the study. It was found that the pH of the infiltration water from the road sub-base with asphalt covered concrete aggregates decreased from 12.6 to below pH 10 after 2.5 years of exposure, whereas this pH was reached within only one year for the uncovered field. Vertical temperature profiles established for the sub-base, could explain the measured infiltration during parts of the winter season. When the release of major and trace elements as function of field pH was compared with pH dependent release data measured in the laboratory, some similar pH trends were found. The field concentrations of Cd, Ni, Pb and Zn were found to be low throughout the monitoring period. During two of the winter seasons, a concentration increase of Cr and Mo was observed, possibly due to the use of de-icing salt. The concentrations of the trace constituents did not exceed Norwegian acceptance criteria for ground water and surface water Class II.
对用于沥青覆盖道路基层的再生混凝土骨料中主要和痕量元素的释放进行了超过 4 年的监测。研究还包括一个没有沥青覆盖、直接暴露在空气和雨水中的类似测试场地，以及一个在基层中使用天然骨料的沥青覆盖参考场地。结果发现，暴露 2.5 年后，带有沥青覆盖混凝土骨料的道路基层渗漏水的 pH 值从 12.6 下降到低于 pH 值 10，而未覆盖场地则在仅一年时间内达到了这一 pH 值。为基层建立的垂直温度剖面可以解释冬季部分时间的测量渗透情况。当将主要和痕量元素作为野外 pH 值的函数的释放与在实验室中测量的 pH 值依赖性释放数据进行比较时，发现了一些类似的 pH 趋势。在整个监测期间，发现 Cd、Ni、Pb 和 Zn 的野外浓度都很低。在两个冬季季节期间，观察到 Cr 和 Mo 的浓度增加，这可能是由于使用了除冰盐。痕量成分的浓度没有超过挪威对地下水和地表水 II 类的接受标准。
