The Effect of Partial Replacement of Cement with Bamboo Leaf Ash on the Mechanical and Durability Property of C25 Concrete Production

Abstract

The construction industry plays a major role in driving economic growth of developed and developing countries. Ethiopia is one of developing country and dramatically expanding construction than ever before. Concrete is the most essential in construction industry and Cement is the basic ingredient of concrete. Nowadays, the construction industry is challenged by the scarcity of cement, price escalation of the cement market and CO2 emissions during cement production. On the other hand, Efficient utilization of agricultural byproduct is the need of today‘s environment to optimize the production cost of materials with the same nature and use. Bamboo leaf is one of such an agricultural waste which is available in high amount in Ethiopia but didn‘t get that much attention. Therefore, the objective of this research work is to investigate the potential of Bamboo Leaf Ash (BLA) as partially replacing cementitious material. In this study, the capability of Ethiopian highland Bamboo Leaf Ash (Yushania alpine) as a partial substitute for cement in C-25 concrete production with 0%, 5%, 10%, 15%, 20% and 25% replacement of OPC were investigated. The chemical composition of Bamboo leaf ash was examined and the summation of major oxide (SiO2, AlO3, and FeO3) is 73.98 % and classified as class F pozzolan. The workability of concrete decreases as the BLA replacement increases, but the setting time, consistency, and soundness of cement paste are increase. On the 28th day, the compressive strength of concrete made with partial replacement of cement by BLA up to 10% attains the target mean strength (33.5Mpa). The flexural strength of concrete made with partial replacement of cement by BLA up to 10% satisfied the required strengths 3.5Mpa for C25. The water absorption and permeability of the BLA blended concrete was lower than the control at 5% ,10% and 15% BLA content, at higher levels of BLA substitution (BLA20% and 25%) observed higher than the control. Concrete mixes with 5% and 10% BLA observed less compressive and flexural strength less in comparison to the control mix due to sodium sulphate attack. Further increase beyond 10% BLA replacement would lead to more compressive and flexural strength less. The result of the SEM pictures shows that the image of BLA10% gives a better mechanical interlocked than control. Generally: BLA has good pozzolanic characteristics and the optimum replacement of cement investigated 10% according to the result and any further increase beyond 10% BLA replacement would lead to strength reduction