Pervious concrete holds great potential\nto mitigate the effects of deicers in stormwater runoff in cold regions and to\nsupport environmental conservation. This\nstudy provided a better understanding of the freeze\/thaw and salt scaling\nresistance of pervious concrete modified with fly ash, with or without graphene oxide.<\/p>\n\n\n\n
Pervious concrete is very porous,\nallowing precipitation and other fluids to pass through directly. The infiltration effect provided by\npervious concrete pavements not only can recharge the groundwater but can also\nreduce the amounts of total suspended solids, phosphor, nitrogen, and metals in\nthe ground water. <\/p>\n\n\n\n
The\nresults of Phase I of this project suggested the potential for using pervious\nconcrete modified with graphene oxide (GO) fly ash in pavement. The primary objectives of Phase II of this project\nwere (1) to evaluate the stormwater infiltration capacity of GO-modified fly ash\npervious concrete; (2) to evaluate the durability performance of GO-modified\nfly ash pervious concrete using freeze\/thaw and salt resistance testing\nmethods; and (3) to use advanced analytical tools to fully characterize the\nGO-modified fly ash binder.<\/p>\n\n\n\n
Test results indicated different degrees of reduction in\nconcentrations of possible pollutants in stormwater, such as copper, zinc,\nsulphate, chloride, ammonia, nitrate, and total phosphate. <\/p>\n\n\n\n
The incorporation of GO significantly\nimproved the resistance of pervious concrete to freeze\/thaw cycles, ambient-temperature salt attack, and \u201csalt\nscaling\u201d of pervious concrete, for both the cement and activated fly ash\nbinder. <\/p>\n\n\n\n
The specimens were examined with X-ray diffraction, which\nrevealed that the mineralogy and the chemical composition of fly ash pastes\ndiffer considerably from those of cement pastes. Nuclear magnetic resonance was\nused to study the chemical structure and ordering of different hydrates, and\nprovided enhanced understanding of the freeze\/thaw and salt scaling resistance\nof fly ash pervious concrete and the role of GO.<\/p>\n\n\n\n