Properties of Concrete Using Bottom Ash N107 Cured in The Tidal Zone

Abstract

In Indonesia, around 9.89 million tons of Fly Ash and Bottom Ash (FABA)waste is generated annually from burning coal in steam power plants (PLTU). One type of FABA waste categorized as Non-B3 which isBottom Ash with a waste code of N107.Ifthis waste not utilized,itwill only become a waste product. With theIndonesia Government Regulation No. 22 of 2021, this waste utilization process becomes more manageable and has the opportunity to be optimized. One of the recommended alternative uses of Non-B3 FABA is substituting raw materials for infrastructure materials, especially for coastal areas where it is difficult to obtain fine aggregate.In the process of development, coastal areas are often in contact with sea air.Seawater has a high salt content which can undermine the strength and durability of concrete, so this study focuses on discussing the effect of using Bottom Ash as a fine aggregatesubstitute on concrete strengthofthe M24concrete, which is influenced by the sea's tides. By using the ACI 211.1-91 concrete mix design method, experimental concrete samples were made by substituting fine aggregatewith bottom ash N107 with a percentage of 0%,20%and 30% and a maximum coarse aggregate size of 20 mm, the treatment of concrete samples was carried out in freshwaterand in the tidal zone. From the sample of concrete with 20% and 30% bottom ash, it is known that the porosity of the concrete immersed in the tidal zone is higher than that of the concrete immersed in fresh water. For concrete that was given maintenance treatment in the tidal zone, the compressive strength decreased at 56 days.