Freedom of design, mass customisation, waste minimisation and the ability to manufacture complex structures, as well as fast prototyping, are the main benefits of additive manufacturing (AM) or 3D printing. A comprehensive review of the main 3D printing methods, materials and their development in trending applications was carried out. In particular, the revolutionary applications of AM in biomedical, aerospace, buildings and protective structures were discussed. The current state of materials development, including metal alloys, polymer composites, ceramics and concrete, was presented. In addition, this paper discussed the main processing challenges with void formation, anisotropic behaviour, the limitation of computer design and layer-by-layer appearance. Overall, this paper gives an overview of 3D printing, including a survey on its benefits and drawbacks as a benchmark for future research and development.

Additive manufacturing (3D printing): A review of materials, methods, applications and challenges

Early age mechanical behaviour of 3D printed concrete: Numerical modelling and experimental testing

Cementitious materials for construction-scale 3D printing: Laboratory testing of fresh printing mixture

Effect of surface moisture on inter-layer strength of 3D printed concrete

Hydration and rheology control of concrete for digital fabrication: Potential admixtures and cement chemistry

Computer vision for real-time extrusion quality monitoring and control in robotic construction

Purpose




This paper aims to report on the experiments with the Contour Crafting Automated Construction process using sulfur concrete as the choice of construction material.




Design/methodology/approach




Several experiments have been performed at centimeter and meter scales. A finite element analysis simulation model for the behavior of sulfur concrete-based structures has been developed. Experimental results were compared with the results of simulation.




Findings




Sulfur concrete has numerous terrestrial applications and is potentially an ideal construction material for planetary construction.




Originality/value




Experimental samples of sulfur concrete were fabricated using a novel mixer/extrusion system. The mechanism was proven to be durable and stable after more than 500 h of work.

Construction by Contour Crafting using sulfur concrete with planetary applications

Several unique systems including the Lunar Electric Rover, the unpressurized Chariot rover, the versatile light-weight crane and Athlete cargo transporter as well as the habitat module mockups and a new generation of spacesuits are undergoing coordinated tests at NASA’s facility for Desert Research and Test Studies (D-RATS). A synergetic simulation plan is proposed for utilizing these maturing systems coupled with a unique, patented robotic fabrication technology called Contour Crafting, tailored for swift and reliable lunar infrastructure development. Landing pads, roads, shade walls and thermal and micrormeteoritic shield and other unpressurized structures that make up a majority of the initial lunar settlement infrastructure may be built using this technology, fully utilizing InSitu Resource Utilization(ISRU) strategy. The intent is to increase astronaut safety, improve buildup performance, ameliorate lunar dust interference and concerns, and reduce time-tocommission, all in an economic manner.

Advances in Contour Crafting Technology for Extraterrestrial Settlement Infrastructure Buildup

In this paper, an automated layer defect detection system for construction 3D printing is proposed. Initially, a step-by-step procedure is implemented to develop a deep convolutional neural network that receives images as input and is able to distinguish concrete layers from other surrounding objects through semantic pixel-wise segmentation. Using data augmentation techniques, 1M labeled images are generated and used to train and test the CNN model. Then, a defect detection module is developed which is able to detect deformations in the printed concrete layers extracted from the images using the CNN model. The evaluation results based on metrics such as accuracy, F1 score, and miss rate verify the acceptable performance of the developed system.

Xiao Yuan

Papers

Cementitious materials for construction-scale 3D printing: Laboratory testing of fresh printing mixture

Computer vision for real-time extrusion quality monitoring and control in robotic construction

Construction by Contour Crafting using sulfur concrete with planetary applications

Advances in Contour Crafting Technology for Extraterrestrial Settlement Infrastructure Buildup

Automated inspection in robotic additive manufacturing using deep learning for layer deformation detection