The construction codes for 3D printed concrete structures have not yet been developed. One reason is the limited number of full-scale construction projects as well as limited structural, mechanical and durability data for 3D printed concrete structures. The freeform nature of construction printing and inability to use reinforcement in the same way as in traditional concrete placement require different designs, structural requirements, and methods of construction which is unprecedented. The unknown factors often result in over-engineering of the structure using higher strength mortars, excess use of materials and the use of reinforcement in the areas which might not provide distinct benefits. Also, the contributing factors in governing acceptable durability and in-service performance of these structures in different climate conditions during and after completion of 3D printing is still unknown.

School

Civil and Environmental Engineering

Research Area

Structural Engineering and construction materials

The state-of-the-art research facility will enable new methods of digital 3D printing by addressing the reinforcement issue and other main challenges of construction 3D printing. Equipment includes: 

  • Two ABB IRB6700 robots with payload of 200 kg and reach of 2.6 m
  • Four vaccum cups and three 2-finger grippers for picking and placing of a range of objects from rheo stater bars to timber frames and studs, bricks, and aerated concrete blocks
  • Concrete mixer-pump for mixing dry powders with water and delivery of  up to 10 m
  • Special-designed nozzle for 3D printing of both one-part and multiple-parts mortars

This project investigates the effect of parameters including printing filament layer size, wall geometry, density, size, and location of rebars as well as climate conditions i.e., temperature, humidity, and wind velocity on constructability, structural, and durability of 3D printed concrete structures. The results of numerical analysis, i.e., finite element modelling (FEM) will be checked against experimental results and field trials. The final outputs of the project will be used in a set of recommendations in developing 3D printing building codes in Australia