Effects of Bamboo Leaf Ash on Alkali-Silica Reaction in Concrete

Abstract

The construction industry is generally faced with so many challenges of which deterioration in concrete structures caused by Alkali-silica reaction (ASR) is one of the pressing challenges. This reaction induces expansion in concrete, resulting in its eventual cracking and subsequent failure. Research direction is being geared towards obtaining properties of pozzolanic concrete of recently discovered different biogenic pozzolans such as bamboo leaf ash (BLA). BLA has been proven to be acceptable in terms of compressive strength and some other properties but few researches have been performed on the impacts of ASR on BLA concrete structures. This research work focuses on investigating the properties of BLA through X-ray diffraction and fluorescence analyses, and its effectiveness in resisting or eliminating ASR that may be present in concrete. Tests were performed on concrete bars soaked in NaOH at a temperature of 80 oC to determine the possible reactivity of aggregates to ASR. In addition, workability and the compressive strengths of BLA concrete at different percentage levels were determined after curing for 7, 28 and 56 days. The findings of the research show that BLA improves the workability of fresh concrete, however, it causes a decline in the compressive strength of concrete when compared with the strength of conventional concrete. Also, BLA has no detrimental effect on the linear expansion of concrete. This study recommends that a 5% partial replacement of cement with BLA will give effective performance when used in areas where strength is not the major priority. Alkali-silica reaction, bamboo leaf ash, compressive strength, concrete, construction, linear expansion, pozzolans