Effect of used engine oil on properties of fresh and hardened concrete

There is a current trend all over the world to investigate the utilization of processed and unprocessed industrial by-products and domestic wastes as raw materials in cement and concrete. This has a positive environmental impact due to the ever-increasing cost of waste disposal and stricter environmental regulations. Historically, reference books on concrete technology and cement chemistry indicate that the leakage of oil into the cement in older grinding units resulted in concrete with greater resistance to freezing and thawing. This effect is similar to adding an air-entraining chemical admixture to the concrete. Such information is not backed by any research study reported in the literature. The objective of the research reported in this paper was to investigate the effects of used engine oil on properties of fresh and hardened concrete. The main variables included the type and dosage of an air-entraining agent (commercial type, used engine oil, or new engine oil), mixing time, and the water/cement ratio of the concrete. Results showed that used engine oil increased the slump and percentage of entrained air of the fresh concrete mix, and did not adversely affect the strength properties of hardened concrete. (C) 2003 Elsevier Science Ltd. All rights reserved.