Cement-based Active Additive Manufacturing: A novel meso-scale multi-materials 3D printing technique for future architectural structures

Additivemanufacturing, also known as three-dimensional (3D) printing, of cement-basedmaterials is considered as the next revolution in construction industry. The 3Dprinting of concrete eliminates the need for formwork and molds, allows thedesign and fabrication of complex shapes and geometric features, and enablesincorporation of additional functionality into a structure. As a result, it haspotential to substantially reduce construction time and labor cost, enhancesafety and reliability, and minimize the environmental footprint of theindustry. Several additive manufacturing techniques for cementitious compositeshave been developed. However, research on the 3D concrete printing is still inits infancy and requires innovative approaches that will introduce a paradigmshift in infrastructure design and construction.

Theestablishment of a multi-material 3D concrete printer with this grant willenable UVA researchers across different disciplines to explore the potentialfunding opportunities in the following topics that represent both current andemerging thrusts in additively manufactured structural systems:

• 3D-FunctionalStructural Components:Current 3D concrete printing technologies mostly allows the fabrication ofstructural components with homogeneous material properties. Interdisciplinaryresearch can be conducted to develop the required computational tools,manufacturing techniques, etc. for 3D multi-material concrete printing, whichwill lead to fabrication of structural elements with functional characteristicssuch as self-adaptive thermal conductivity, tunable acoustic properties, andspatially varying composition.
•  Developmentof Fabrication System:Additive manufacturing (AM) enables building structures to be fabricated insmall components off-site and assembled on-site. This approach is related to thelimitation and capacities of material and fabrication systems. Improving thisapproach relies on developing a novel method of fabrication to scale up thesize of building components. This process requires to investigate on developinga large scale of 3D printer or developing a customized end-effector for roboticfabrication.
• Shapeand Topology Optimization:3D concrete printing provides enormous freedom in shapes and structural design,but existing 3-D printed structure are identical to conventional building.  To achieve more sustainable andcost-effective designs, computationally optimized designs can be made that donot resemble existing structures and cannot be constructed without 3D printingtechnology. 
• 3DPrinted Smart and Bio-Inspired Structures: Additive manufacturing allows deposition of smartmaterials such as self-sensing concrete to desired locations to incorporatefunctionality to structures. Future research can also explore the possibilitiesoffered by 3D printing and bio-inspired design to integrate additionalfunctional characteristics to 3D printed concrete structures.
• 3DPrinting Material Development and Characterization: As additive manufacturing providesan opportunity to optimize the cementitious mixture used in construction, newmixtures that uses inorganic or mineral-based minerals as binder can bedeveloped. There is also need for advancement in metrology and characterizationof the processing-microstructure-property relationship of high-performancecementitious composites with Portland cement paste for 3D printing.