Experimental Study on the Mechanical Properties of Green Lightweight Cement Composite Modified by Nano Additives

Cement materials have been commonly used in the building and construction industries. However, the process of cement manufacture has long been connected with high consumption of energy and adverse environmental impacts. In this study, in order to produce innovative green cement material that consumes lower energy, resources and is more eco-friendly, industrial waste by-product fly ash cenosphere (FAC) has been utilized as lightweight aggregate to replace cement by 73.3 %. Most research regarding lightweight cement materials with FAC has mainly paid attention to the influence of FAC and the reinforcement via fibre materials, but very few studies have been devoted to the incorporation of nano additives. Therefore, 0.05 %, 0.15 %, 0.45 % of carbon nanotubes (CNTs) and 0.2 %, and 1.0 % of nano silica (NS) were used to modify lightweight cement composite (LWCC). Experiments including flexural strength test, compressive strength test, and thermogravimetric analysis were performed to evaluate the mechanical behaviours and the hydration process of the produced LWCC. Based on the experimental outcomes, incorporating CNTs and NS can effectively contribute to enhancing both flexural and compressive strength, and facilitate cement hydration reaction.