Chemical shrinkage, autogenous shrinkage, drying shrinkage, and expansion stability of interfacial transition zone material using alkali-treated banana fiber for concrete

It might be of interest for authors to learn more that in the early 1900s, fibers were used in cement-based material, as cement-based materials exhibit shrinkage cracking over time, which can be controlled by adding fibers. The main aim of the inserting natural fiber into cement-based material is to decrease the shrinkage of cement-based material, prevent the rising of shrinkage cracks, and develop low-cracking cement-based material. In the research, the same aim aforementioned was kept same way. For carrying out the aim, agricultural waste, known as banana fiber (BF), can be considered a shrinkage reducer, expansion stabilization, a renewable material and has potential to make cement-based material transformed into a green construction material. This research investigated the effect of BF incorporation on cement paste shrinkage. Thus, five mixes were developed with different BF additions based on the total volume of cement paste (0, 0.5, 1, 1.5 and 2%). For each mixture, four tests were carried out to assess the impact of BF addition on the paste's volume stability: chemical, autogenous, drying shrinkage and expansion. Testing was conducted for up to 90 days. Compared to the control mix, the addition of 2% BF reduced chemical shrinkage, autogenous shrinkage, drying shrinkage, and expansion by 27%, 57%, 47%, and 66%, respectively. Furthermore, a positive correlation was observed between chemical shrinkage and both autogenous and drying shrinkage and the percentage of BF content. Conversely, there was an inverse relationship between chemical shrinkage and expansion. The most significant conclusion to emerge from this study is that the incorporation of banana fiber (BF) into alkali-treated concrete results in a reduction in chemical shrinkage, autogenous shrinkage, drying shrinkage, and expansion. This is attributed to the molecular structure of BF, which is characterized by uninterrupted glycosidic linkages, leading to alkaline breakdown within the alkaline environment. Consequently, the alkali-treated BF can be described as a volume stability admixture in concrete technology.