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This paper aims to provide a global snapshot of concrete 3D-printed buildings and to uncover robotic-oriented large-scale fabrication strategies. Therefore, an extensive internet search and literature review was carried out to investigate 3D-printed buildings. In this study, 154 construction projects with 204 buildings were systematically recorded and evaluated from 2013 up to 2023. Using an exploratory mixed-methods approach and a comparative case study analysis, a total of 88 3D-printed buildings were first evaluated descriptively. Thereafter, different existing printing strategies for in situ, on-site, and off-site production were identified, using an iterative approach. In addition to the geographical distribution, the descriptive evaluation also showed the key players as drivers for the spread of the 3D-printing technology and the correlations between printer type, fabrication strategy, and the building size. With regard to the printing strategy, three different approaches for in situ and off-site fabrication can be defined, depending on the printer types and their characteristics (work size and mobility): print-in-one-go, horizontal or vertical segmentation, and the multi-element vs. full-scaled wall strategy. However, the study showed that the data quality was sometimes difficult due to a lack of information and essential details of the printing process and segmentation.

The aim of this study is to question the need for alternative project delivery methods to foster the integration of concrete 3D printing in the construction industry. For this purpose, a literature review was carried out. The results indicate that the traditional planning and construction process will have to be reconsidered. On the one hand, new roles and changes in responsibilities may emerge, and, on the other hand, a holistic design process and early contractor involvement will be required to fully exploit the potential of concrete 3D printing. Therefore, alternative project delivery models need to be adopted.

Additive manufacturing (AM) with concrete, also known as concrete 3D printing, is one of the most interesting approaches for disrupting the construction industry and is currently subject to numerous research activities worldwide. AM has great potential to decrease labour costs and increase the material efficiency and geometric complexity of non-standardised building components. Although prior investigations have shown various fields of application for AM with concrete, the full potential with respect to different structural component types has not been covered yet. With this paper, an up-to-date review of fabrication strategies for the main structural components, (1) walls, (2) columns, (3) slabs, and (4) beams, is provided to identify trends and existing challenges. Therefore, firstly, AM methods and their underlying principles and characteristics for concrete components are presented, and secondly, fabrication strategies for each AM method are shown. The investigation uncovers different AM strategies (direct part vs. indirect “permanent formwork”; in situ, on-site, or off-site), which are currently being used. As a result, future applications of AM will require a hybrid manufacturing strategy combining conventional and additive manufacturing to fully explore its potential.

In Singapore, there is an increasing need for independence from manpower within the Building and Construction (B&C) Industry. Prefabricated Prefinished Volumetric Construction (PPVC) production is mainly driven by benefits in environmental pollution reduction, improved productivity, quality control, and customizability. However, overall cost savings have been counterbalanced by new cost drivers like modular precast moulds, transportation, hoisting, manufacturing & holding yards, and supervision costs. The highly modular requirements for PPVC places additive manufacturing in an advantageous position, due to its high customizability, low volume manufacturing capabilities for a faster manufacturing response time, faster production changeovers, and lower inventory requirements. However, C3DP has only just begun to move away from its early-stage development, where there is a need to closely evaluate the process parameters across buildability, extrudability, and pumpability aspects. As many parameters have been identified as having considerable influence on C3DP processes, monitoring systems for feedback applications seem to be an inevitable step forward to automation in construction. This paper has presented a broad analysis of the challenges posed to C3DP and feedback systems, stressing the admission of process parameters to correct multiple modes of failure.

Additive manufacturing technologies are becoming more popular in various industries, including the construction industry. Currently, construction 3D printing is sufficiently well studied from an academic point of view, leading towards the transition from experimental to mass large-scale construction. Most questions arise about the applicability of construction 3D printers for printing entire buildings and structures. This paper provides an overview of the different types of construction 3D printing technologies currently in use, and their fundamental differences, as well as some significant data on the advantages of using these advanced technologies in construction. A description of the requirements for composite printing is also provided, with possible issues that may arise when switching from lab-scale construction printing to mass large-scale printing. All printers using additive manufacturing technologies for construction are divided into three types: robotic arm printers, portal-type printers, and gantry 3D printers. It is noted that gantry printers are more suitable for large-scale printing since some of their configurations have the ability to construct buildings that are practically unlimited in size. In addition, all printers are not capable of printing with concrete containing a coarse aggregate, which is a necessary requirement in terms of the strength and economic feasibility of 3D printing material for large-scale applications.