INVESTIGATING THE VIABILITY OF BANANA LEAF ASH AND SCORIA POWDER IN THE PRODUCTION OF PUMICE BASED GEO-POLYMER CONCRETE AND TO EXAMINE THE MECHANICAL PERFORMANCE AT A HIGH TEMPERATURE.

Abstract

Because of the energy consumption and CO2 emission raised about the cement industry, it is now believed that new binders are indispensable to completely replace the Portland cement in concrete production. The scientific community is continuously studying and researching the development of novel cements other than Portland cements using large amounts of waste as a raw material. This innovative binder material is termed as geopolymer concrete. This study aimed to investigate the viability of banana leaf ash and scoria powder in the production of pumice-based geo-polymer concrete and to examine the mechanical performance at a high temperature. Pumice, and scoria powder are Natural pozzolanas, and agricultural waste such as banana leaves are used in this investigation. Chemical activators such as sodium hydroxide (NaOH-12M) and sodium silicate (a ratio of 2.5 concerning NaOH) and high-range water reducer (2%) were used. Pumice and scoria are locally available materials purchased from local markets and grounded by LAA and BLA in agriculture by-products found locally available materials produced and burned in an open environment by using a metal drum. After these, it was burned in the blast furnace at a temperature of 600 °C for 2 hours. The study examined the chemical composition and physical properties of pumice, scoria, and BLA, the workability of fresh concrete, the mechanical properties (compressive, split tensile, and flexural strength at 7 and 28 days) and durability(water absorption) at 28 days, and also the microstructural analysis (SEM and XRD) at 28 days of GPC was conducted. In addition to for cube specimens elevated temperature at 28 days by muffle blast furnace for 1hrs were examined. The maximum strength recorded during 28 days was 16.33MPa, 2.1 MPa, and 4.6 MPa for compressive strength (ASTM C39) split tensile strength (ASTM C496), and flexural strength (ASTM C78-02) respectively from M1(pumice100%) mixture. For the remaining mixtures, a reduction was observed with the increase in replacement level. The approximate reduction observed in compressive strength was 7%, 14%, and 18% for M2, M3, and M4 mixtures, respectively. Overall, it has been observed that replacing Pumice with Scoria and BLA reduced the mechanical performance of geopolymer concrete. However, all the mixtures can be used in the production of non-structural memb