کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5751564 1619706 2017 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Long-term leaching from recycled concrete aggregates applied as sub-base material in road construction
ترجمه فارسی عنوان
اشباع بلند مدت از بتونه های بازیافت بتونه به عنوان مواد زیر پایه در ساخت و ساز جاده استفاده می شود
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
چکیده انگلیسی
In the present study, the metal leaching from recycled concrete aggregates (RCA) used in road sub-base is presented after > 10 years of exposure. The released levels of inorganic constituents, the effect of small variation of pH and the use of de-icing salt during winter season were studied. In addition, speciation modelling for the major elements has been provided. The pH varied from 7.5 to 8.5 for the sub-base constructed with RCA whereas the pH of around 8 was obtained for the test section not affected by the traffic and de-icing salts. Despite a small variation in pH, the leachability of Al, Ca and Mg was found to be strongly dependent on pH and fair agreement between the measured and predicted concentrations was obtained. The speciation modelling indicated that gibbsite, calcite and magnesite controlled the solubility of Al, Ca and Mg, respectively, which was in agreement with the expected carbonation products. Due to the larger pH fluctuations in the test sections exposed to the road traffic, increased concentrations were observed for the oxyanions. The same effect was not seen for the trace metal cations Cd, Cu, Ni, Pb and Zn. The distinct pH dependent leaching profile (solubility maximum in the mildly basic pH region) for vanadium could be seen after 10 years of exposure. The simplified risk assessment showed that the released quantities did not exceed the chosen acceptance criteria for groundwater and fresh water. The results obtained for the test section not influenced by road dust and de-icing salts, complied with these criteria even without considering any dilution effects caused by the mixing of pore water with groundwater.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Science of The Total Environment - Volumes 587–588, 1 June 2017, Pages 94-101
نویسندگان
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