A. Amirfiroozkoohi, M. Valiente Lopez , M.C. Sanz Contreras

Universidad Politécnica de Madrid, Escuela Técnica Superior De Edificación De Madrid (SPAIN)
The main principle of 3D printing is that it is an additive manufacturing technique, in dissenting to the traditional subtractive manufacturing techniques. The advantages of concrete 3D printing compared to the methods used today are that it could be a cheaper, faster, and more environmentally friendly manufacturing process. 3D printed concrete is a kind of concrete that can be used through a 3D printer layer by layer without any kind of framework and vibration process. Its pivotal performance indexes, such as workability, setting and hardening time, and mechanical properties, can be optimized by materials selection and printing parameters.

Construction is one of the largest sectors of the global economy, with construction-related spending at $10 trillion globally, equivalent to 13% of GDP. In the construction industry, similar rapid prototyping technology that does not use conventional form can be applied to meet the demand on free formed structures that can provide aesthetic value and functionality. Conventional formwork can increase construction cost and period for various structure with complex shapes while it has several advantages such as high strength, convenience, accuracy, good quality of surface roughness even recyclable reparable to the environment is an urgent, and critical focus.

The aim of this research is to examine the workability of fresh concrete used as material for additive manufacturing. 3D concrete printing is an innovative construction method that promises to be highly advantageous in the construction field in terms of optimizing construction time, cost. A model with construction software is designed with AutoCAD or other programs, and every section is analysed with a program like MATLAB, error reduction, and environmental aspects. Quality of the final printed structure is significantly affected by the properties of fresh concrete, which must possess suitable workability in order to be extruded through an extruder head (printability), maintain its shape once deposited and not collapse under the load of subsequent layers (buildability). Even the research aspires towards this classification through the use of parametric modelling tools, analytic software, quantitative and qualitative analysis. Rapid prototyping, which is the automatic construction of physical objects using additive manufacturing technology, usually employs materials intended for the immediate analysis of form, scale, and tactility.

This study will examine the different aspects of printable concretes, including permeability, extrudability, and buildability, using different computer programs to find out the best way of constructing printed structures in a larger scale and with fewer expenses. Although there are some valuable studies in this field, there are a few ones which estimate all the requirements of printable concretes. This research will try to find the best method of this new technology to replace the traditional way. The future results of compressive and flexural strengths for printed and casted specimens will be comparatively analysed.