Use of triisopropanolamine to control the loss in strength and durability of concrete containing used engine oils

Triisopropanolamine (TIPA) is an organic ethanolamine commonly used to neutralize the clinker surface charges during grinding and foster the cement hydration kinetics and formation of hydrated products. This paper assesses the efficiency of incorporating TIPA to control the loss in strength in concrete mixtures containing used engine oils (UEOs). An oil-based defoamer was systematically used in this work to control air entrainment in freshly mixed concrete. Regardless of the cement content and water-to-cement ratio, the use of TIPA proved efficient to compensate the negative influence of UEOs on the concrete mechanical strengths and durability properties. Hence, for example, the incorporation of 0.7% UEO required about 0.08% TIPA to restore the concrete properties, while the use of 0.9% UEO required about 0.12% TIPA. Such data can be of interest to concrete practitioners and municipalities for circular economy and appropriate valorization of UEOs in the construction industry.