Additive manufacturing: Technology, applications, markets, and opportunities for the built environment

Additive manufacturing (AM) technologies (also known as 3D printing - 3DP) have been rapidly advancing into various industrial sectors, including aerospace, automotive, medical, architecture, arts and design, food, and construction. Transitioning from the visualization and prototyping stages into functional and actual part replacement opens further design possibilities. Among the diverse applications of AM, construction applications have not yet seen a commercially available and widely used product in the market. Nevertheless, it has been a subject of interest to researchers in recent decades. There are evident challenges and risks for the integration of AM towards large-scale construction. Therefore, progress in their commercialization seems to proceed at a slow pace, as only a few 3DP trials for large-scale construction can be found in the literature. This paper aims to provide a comprehensive and evidence-based baseline along with progresses in relevant disciplines related to 3DP in construction, which will provide an opportunity to experts in all domains to understand the multi-dimensional constraints and to specify the future research directions in these sectors. The distinct merit of this article is that it provides, for the first time, a diverse review on literature in the field of construction 3D printing. It offers up-to-date and in-depth information of hindrances (from processes, materials, structural design and standards) which add up towards low pace of automation in construction sector, identify deficiencies in the current research and provides future research trends for researchers. The findings from intensive literature review will guide engineers, designers and investors from construction sector to grab research gaps and business opportunities. First of all, the development of different 3DP processes in built environment are presented to highlight the process constraints along with the commercial applications of these processes for industrialists and investors to identify the business opportunities. Secondly, process parameters and difficulties in optimization of material mixtures are presented as a guide to civil engineers following the discussion on materials urging the need for development of eco-efficient and environment friendly materials. Conclusions drawn from discussion in individual sections along with issues/constraints and challenges involved are explained separately.