THE USE OF CASHEW NUTS SHELL ASHES AS PARTIAL REPLACEMENT OF CEMENT FOR MAKING NORMAL CONCRETE IN TANZANIA

Abstract

This study investigates the feasibility of using Tanzanian Cashew Nut Shell Ash (CNSA) as a partial replacement for Portland cement in concrete production. Unlike previous studies that utilized CNSA from India, Brazil, and Nigeria, this research focuses on Tanzanian CNSA, whose chemical composition and properties remain unexplored. Tests, including X-ray fluorescence, compressive strength, flexural strength, water absorption, and ultrasonic pulse velocity, were conducted on concrete samples cured for 7, 28, and 56 days. The results confirm that Tanzanian CNSA meets pozzolanic material standards and its concrete demonstrates promising performance as a construction material, with its suitability varying based on the curing period and cement replacement levels ranging between 5% to 10%. This study highlights CNSA's potential to promote sustainable construction practices while addressing waste management challenges in Tanzania.