Evaluation of pozzolanic activity and environmental assessment of cement composites with lubricating oil re-refining ash. (2nd May 2023)

• Record Type: Journal Article
• Authors: Ramos da Silva, Alex; Friol Guedes de Paiva, Fábio; Henrique Pereira Silva, Lucas; Fernando dos Santos, Luis; Roefero Tolosa, Gabrieli; Eloizo Job, Aldo; Pérez Galvín, Adela; López-Uceda, Antonio; Rainho Teixeira, Silvio; Kinoshita, Angela; José dos Santos, Renivaldo
• Is Part Of: Construction & building materials. Volume 376(2023)
• Publication Date: 2023-05-02
• Subjects: Lubricating oil -- Environmental assessment -- Pozzolanic activity -- Eco-efficiency -- Compressive strength; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2023.130980
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Supplementary cementitious materials can be prepared from lubricating oil re-refining. Mortar with OPC replaced by 30% of LORR reached same compressive strength of reference. LORR present pozzolanic activity and can replace OPC in mortar composition. Using LORR in mortars demonstrated economic and environmental feasibility. Mortars up to 40% of LORR does not present an environmental hazard by leaching test. Abstract: Lubricant oil is considered a hazardous waste, and its disposal in the environment represents a high risk of damage to ecosystems. The purpose of this work is to study the feasibility of using lubricating oil re-refining ash (LORR) as a pozzolanic material in mortar composites with 0–40% of cement replaced by LORR, and determining the optimal content. Systematic experiments were performed to investigate the effects of LORR on the cementitious material properties, including workability, mechanical and flexural strength and water absorption. Furthermore, the hydration of the cement pastes was analyzed using thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The results showed that LORR has high pozzolanic reactivity, increasing portlandite consumption, contributing to the additional formation of calcium silicate hydrate gel. Up to 30% LORR replacement resulted in similar mechanical properties to the control mortar. The leaching test showed that the raw LORR release 9 hazardous substances, including 6 heavy metals. The mortar proved to be effective for encapsulating all substances studied, in addition to contributing to the reduction of hazardous waste deposition in industrial landfills, and reducing the cost (less than24%) and embodied energy (less than29%) of eco-friendly cementitious materials. Therefore, the potential of lubricating oil re-refining ash for application in civil construction was demonstrated.