Material development for lightweight 3D concrete printing

Abstract

The construction industry in Singapore is facing several challenges such as growing construction demand, highest workplace fatal injuries and low productivity rate. With the rapid urbanisation, construction industry in Singapore is encouraged to adopt more sophisticated technology like 3D concrete printing (3DCP). 3DCP can make a revolutionary change to construction industry which is constantly facing the pressure to meet tight schedules and budgets. 3DCP could help to reshape the construction industry by shorten the construction time, cheaper cost, lesser labour usage, reduce human errors and resulted in lesser worker injuries and fatalities. In this study, possibility of incorporating lightweight materials with 3DCP is investigated. The appropriate mix proportions and percentage of sand replacement with lightweight materials will be carefully evaluated. The effects of different lightweight materials on the concrete’s rheological properties in the fresh concrete state will also be discussed. The rheological properties of fresh concrete samples are obtained from Anton Paar rheometer with a vane geometry using constant angular velocity protocol and creep recovery protocols. The rheological properties to be discussed are static yield stress, dynamic yield stress and plastic viscosity.