The Effect of Printing Direction on the Strength Characteristics of a 3D Printed Concrete Wall Section

Abstract

Digital construction is expected to reduce the high volume of waste and the labour shortage in the construction sector. The properties of hardened concrete used in 3D printing depend on numerous parameters within the manufacturing process. This study collected data using 208 specimens to measure the effect of the loading direction relative to the printing direction on the strength characteristics of printed concrete. The compressive strength was not significantly affected by the directions, but showed a 30% reduction from mould-casted strength due to lesser amount of compaction in the printing process. Flexural tensile strength showed a 14% reduction in one direction, possibly caused by heterogeneity due to the use of extrusion head with a 35% smaller diameter than the width of the layer. Splitting tensile strength was 14% lower when split between the printed layers. Splitting tensile strength is possibly 5% higher when PP fibres are oriented favourably.

Keywords

• 3D concrete printing
• mechanical properties
• compressive strength