Alkali Activated Binders Based on Biomass Bottom Ash and Silica By-Product Blends

Abstract

Due to the growing number of biomass boiler plants there are rapid growth of biomass combustion by-products. The key point of this investigation is to utilize biomass bottom ash (BBA) and silicagel by-product (SB) in the matrices of alkali activated binders. BBA and SB are the main ingredients of aluminumsilicate precursor. This aluminosilicate precursor is a potential initial material for the preparation of alkali activated materials (AAMs). Currently, in Lithuania there are more than 160 biomass boiler plants and few more are under construction. These types of plants generate more then 25–30 thousand tons of BBA. In this paper, the compressive strength of alkali activated binders specimens was dependent on the amounts of SB and alkali activator. The hydration products of AAMs were analyzed by XRD, SEM and FT-IR. The highest compressive strength (21.6 MPa) was observed in specimens based on biomass bottom ash and 35% of SB. This blended mixture of the locally available by-product (BBA and SB) have potential to produce eco-friendly AAMs binder.