Green Concrete Development: Evidence from Waste Concrete and Hemicellulose Utilization

Abstract

Natural resource scarcity, CO 2 emissions, and solid waste generated from the construction industry are major global environmental and developmental challenges, posing threats to the sustainability of terrestrial and aquatic ecosystems. In response to this multifaceted issue, recent studies focus on developing non-cement concrete, distinct from traditional cement-based compositions, by utilizing recycled concrete and wood waste molded at high temperature and pressure. Although wood hemicellulose shows adhesive properties and bonds particles at lower temperatures, it has not been studied in non-cement concrete. Hence, the present study focuses on developing green concrete using recycled concrete and hemicellulose, and further enhancing its strength with chitosan. The study used the press molding method with different pressing temperatures. The results, compared with conventional cement mortar and other wood components, revealed that hemicellulose-based green concrete exhibited superior bending strength compared to the other the components and even surpassed the strength of conventional cement mortar. Furthermore, an elevation in temperature to 60˚C resulted in enhanced strength, but a further increase to 160˚C led to delamination and thus a reduction in strength. Moreover, hemicellulose, when substituted by 50% of its weight with chitosan, further enhanced the strength of the concrete. The results also showed that hemicellulose has the potential to produce green concrete from abundant plants in a time interval of no more than ten minutes.