Engineering Properties and Hydraulic Characteristics of Cement Kiln Dust Modified Pervious Concrete

Resumo

Pervious pavements provide a vital solution to urban environmental engineering issues through their ability to reduce stormwater runoff and improve water quality. Pervious concrete, the most commonly used material in pervious pavements, uses almost the same materials as traditional concrete except the fines are eliminated allowing for minimal particle packing. Although pervious concrete has been used successfully in many countries for the past 30 years, the amount of CO2 released to the atmosphere (5% of global manmade CO2 emissions) during cement production is a major concern of both the scientific and engineering communities. There is a need for alternative, sustainable materials that perform at the same levels as current materials.
This study assessed the properties of modified pervious concrete containing cement kiln dust (CKD). Cylindrical specimens were prepared using various ratios of aggregate to cement (A/C, by weight), water to cement (w/c) and CKD to cement (CKD/C). The specimens were then tested for hydraulic conductivity and strength. Results showed an inverse relationship between hydraulic conductivity and CKD/C ratio and a direct relationship between indirect tensile strength and CKD/C. The hydraulic conductivity and strength values of specimens were within the expected values found in the literature for porous materials. This work not only produced a new class of sustainable durable materials, but also recycled a large quantity of industrial waste that was otherwise sent to landfills.