Compressive Strength Evaluation of Concrete with Palm Tree Ash

Abstract

Concrete industry produces high carbon dioxide emissions that are harmful to the environment. As cement is the primary artificial component of concrete, most of the past studies focused on reducing the cement content in concrete manufacturing. To enhance the sustainability of concrete production, generally, cement is partially replaced with waste materials with similar characteristics such as silica fume and fly ash. One of the sources of such waste materials in date-producing countries is palm trees since each palm tree produces approximately 23 kg of waste annually. Currently, very limited use of palm tree waste exists in the concrete industry; specifically, palm tree leaves ash (PTA). This study is intending to evaluate the potential of adding PTA to concrete as a cement replacement by evaluating the compressive strength of PTA concrete. Several concrete cylindrical specimens were cast with variable percentages of added PTA. Three dosages of PTA (5%, 10%, and 15%) were added to the concrete as a substitute for cement by weight. The palm tree ash added to concrete was collected from burned palm tree branches and filtered based on its fineness. Assessment of the compressive strength of PTA-based concrete was performed at ages of 7, 28, and 56 days. The results of evaluating the compressive strength of the specimens showed that the concrete mixed with only 5% PTA possesses around 12% higher compressive strength than that without PTA. Further, increasing the dosage of added PTA to concrete yielded unfavorable results in terms of increasing the compressive strength. The addition of more than 10% of PTA to concrete as a replacement for cement triggered a significant reduction in compressive strength of the concrete. The findings of this study encourage partial replacement of cement with PTA in concrete up to 5% to reduce concrete carbon footprint and enhance sustainability of concrete manufacturing process with maintaining desired mechanical properties.