UC Pavement Research Center
Available online at: https://trid.trb.org/view/1572857
Wang, Hanbing, Hui Li, Xiao Liang, Haonan Zhou, John T. Harvey (2019) Investigation on the Mechanical and Environmental Properties in High Performance Pervious Concrete Containing Fly Ash. Transportation Research Board 98th Annual Meeting
This study firstly presented an adequate experimental investigation on the influences of the cement-aggregate ratio (C/A) on porosity and compressive strength of pervious concrete samples, and determined an optimum C/A for higher compressive strength. Secondly, 0%~40% fly ash was chosen as supplementary cementitious material to replace Portland cement at the optimum C/A. Then a series of environmental investigations like Suspended Solids, Ammonia-nitrogen, Total Phosphorus, and Alkali precipitation tests was carried out to explore the purifying effect on concrete samples. Finally, this paper creatively introduced zebrafish acute biotoxicity test to analyze whether pervious concrete containing fly ash could be used for runoff pollution control and rainwater recycling. According to the results, C/A has a significant influence on the properties of pervious concrete, and there exists an optimal range of C/A for better compressive strength. A fine linear relationship was found between compressive strength and porosity. For pervious concrete containing fly ash, higher fly ash content indicates lower porosity and permeability. With the adding of fly ash, the compressive strength reaches 35.4 MPa (maximum) at 20% content compared to 25.7 MPa without fly ash and then presents a decreasing trend. There was no significant difference between purifying effect of fly ash samples and general samples. However, the percolate from fly ash samples killed all of the fish within 20 minutes and the disposed percolate performs much better. Generally, C/A (0.20~0.24) and 20% fly ash content are recommended to produce pervious concrete with high strength, but the percolate needs to be disposed for ecological benefits.
Key words: Compressive strength, environmental impacts, fly ash, high performance concrete, mechanical properties, pollution control, porosity, runoff