Use of stone columns for quick drainage and temperature reduction in porous pavement

Today, extreme weather conditions occur globally due to climate change, and roads with traditional impermeable pavement could cause environmental problems, such as urban flooding and heat islands. Although porous pavement is an important environmentally friendly alternative pavement structure for roads, it has many disadvantages and is not yet widely used. Therefore, this paper reported the use of stone columns in the soil subgrade of porous pavement to improve the performance of roads. Soil property tests were conducted to evaluate the permeability of subgrade soil in a field area at different depths. Stone columns with different heights and various aggregate sizes were installed in the soil subgrade in the laboratory and the field, with the concrete footing on top of the stone columns as the bedding course of the pavement. Quantitative comparisons of the permeability of stone columns in the laboratory and the field were undertaken. In addition, the temperature changes in the stone columns and concrete footings before and after watering were tested to investigate the influence of the stone columns on the thermal behavior of roads. The test results showed that stone columns improved the water drainage in porous pavement and contributed to temperature reductions in urban roads. Therefore, the use of stone columns is recommended in porous pavement to improve water drainage and mitigate urban heat islands.