Measurement of pore volume, connectivity and clogging of pervious concrete reactive barrier used to treat acid mine drainage

Permeable Concrete Barriers to Control Water Pollution: A Review

“…Both types of aggregates had a fairly equal removal performance for sulfates (Gr = 30% and D =29.3%); calcium (Gr = 84.7% and D = 85%); and iron (Gr = 99.5% and D = 99.6%). Another study assessed the hydraulic performance of permeable concrete of different aggregate types that was used in the treatment of acid mine drainage [180].In that work, the effect of using 30% fly ash as an SCM was addressed at different water-to-cement ratios (0.25-0.27), and different coarse aggregates were used, including dolomite (67 and 95), granite , shale (67), and andesite (67) [180]. The studied samples were reported to have effective removal performances after 90 days for Al (98.1%), Mg (86.5%), Mn (99.8%), Zn (97.4%), and Fe (99.4%), with an increased chromium concentration due to chromium leaching (−112%) from the cement and fly ash.…”

“…Permeable concrete has been investigated for its potential use in the construction of permeable reactive barriers for ground water remediation [30,31,154,156,[173][174][175][176][177][178][179][180][181][182][183]. In particular, these research efforts were directed toward the assessment of the potential use of these materials for the remediation of acidic contaminated groundwater, in particular contamination from acid mine drainage, in which the high buffering capacity of these materials will sustain its performance over long periods of time.…”

“…The beneficial use of fly ash to improve the mechanical strength of permeable reactive concrete barriers and to provide more active sites for the removal of pollutants is promising [31,174,178,179]. Yet, it was concluded the cement can contribute to an increase in the Cr concentration in the treated plume [178,180]. This point needs to be addressed in depth by investigating the stability of fly ash using a standardized test (e.g., TCLP) to assess the feasibility of this material's use.…”

“…• The effect of the rheological characteristics of permeable concrete paste and their effects on the hydraulic and pollutant removal performances have been not investigated for permeable reactive concrete barriers. Most of the conducted studies relied on the use of the minimum amount of water (0.21-0.33) in conventional permeable concrete [30,31,156,179,180]. This limited range compared to that used in the low-development impact (0.25-0.45) practices reduces the porosity of the hardened material.…”

“…The available experimental data on the performance of permeable concrete reactive materials were conducted within limited time frames of less than a year [21,24,176,178,180,183]. The long-term performances of these materials are required to be studied in depth to ensure the sustainable performance of these barriers throughout their service life and to identify threshold values for their reduced performances affecting their efficiency as a barrier.…”