The application of additive manufacturing (AM) in construction has been increasingly studied in recent years. Large robotic arm- and gantry-systems have been created to print building parts using aggregate-based materials, metals, or polymers. Significant benefits of AM are the automation of the production process, a high degree of design freedom, and the resulting potential for optimization. However, the building components and 3D-printing processes need to be modeled appropriately. In this paper, the current state of AM in construction is reviewed. AM processes and systems as well as their application in research and construction projects are presented. Moreover, digital methods for planning 3D-printed building parts and AM processes are described.

Additive manufacturing in construction: A review on processes, applications, and digital planning methods

Additive manufacturing as an enabling technology for digital construction: A perspective on Construction 4.0

https://repository.tudelft.nl/islandora/object/uuid%3Aac5c1cb4-32be-4c93-9457-1cbab752c8da/datastream/OBJ/download

Improving printability of limestone-calcined clay-based cementitious materials by using viscosity-modifying admixture

A theory of the evolution of technology: Technological parasitism and the implications for innovation magement

This study investigated the properties of alkali activated slag (AAS) binders formulated for extrusion‐based 3D printing. The fresh properties of AAS mixes were tailored through the use of nanoclay (NC) and nucleation seeds. The printability criteria employed were the ease of extrusion (extrudability) and the stability of the layered structure (buildability). Introduction of 0.4% NC in AAS mixes led to improved thixotropic properties due to the flocculation effect, which accounted for the extrudability and shape fidelity of the binder. Inclusion of 2% hydromagnesite seeds in this mix design provided additional nucleation sites for the increased precipitation of hydrate phases, resulting in denser microstructures. This enhanced the hydration reaction and improved the structural build-up rate necessary for large-scale 3D printing. The developed AAS mix containing 0.4% NC and 2% hydromagnesite seeds was used in the printing of an actual 3D structure to demonstrate its feasibility to be used in 3D printing applications.

/pdf/investigation-of-the-properties-of-alkali-activated-slag-48opkyuwn4.pdf

Investigation of the properties of alkali-activated slag mixes involving the use of nanoclay and nucleation seeds for 3D printing

Perspectives on a BIM-integrated software platform for robotic construction through Contour Crafting

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

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.

Omid Davtalab

Papers

Perspectives on a BIM-integrated software platform for robotic construction through Contour Crafting

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

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