Development and evaluation of ecoefficient cementitious compositions for application as 3D printing

• Grant number: 20/01515-8
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2020
• End date: April 30, 2022
• Field of knowledge: Engineering - Civil Engineering - Construction Industry
• Principal Investigator: Rafael Giuliano Pileggi
• Grantee: Francisco Jordão Nunes de Lima
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 17/50343-2 - Institutional development plan in the area of digital transformation: advanced manufacturing and smart and sustainable cities (PDIp), AP.PDIP

Abstract

The construction industry needs to modernize due to pressure from society, the market and due to environmental impacts. In this sense, the construction industry has financed the development of research based primarily on increasing productivity, improving the efficiency of construction methods, reducing time, cost and materials in production, limiting dependence on labor and at the same time improving quality of work. The solution pointed out by many researchers is the development and insertion of the additive manufacturing (MA) technology in civil construction, the most suitable being the wire extrusion method. This technique comprises a set of computer-controlled operations, based on the extrusion of cementitious pastes to create components layer by layer. However, the consolidation of such a technique depends, among other things, on the development of an appropriate cementitious composition, since the consumption of cement in these solutions is high, which is the main challenge of this research. The cementitious paste requires a high content of fines and ultrafines, in part, due to the removal of coarse aggregates from the composition to have less interference with the flow, from the rheological point of view. The development of such compositions with high cement consumption, mainly due to the difficulty of adapting the rheological properties during the extrusion/3D printing process. For that, organic additives are required in the compositions and the adequate proportion of the raw materials based on particle packaging concepts, in order to guarantee resistance gain and evolution of the elastic modulus of the material in a short time. In this context, the master's project aims to develop extruded cementitious compositions with low binder consumption, for application in civil construction using the 3D printing technique by wire extrusion. The aim is to contribute to improving the productivity of construction activities and minimizing socio-environmental and economic impacts. To achieve this objective, initially the physical, chemical and mineralogical characterization of the materials will be made, and then the properties of the compositions will be evaluated both in the fresh and in the hardened state, comparing them to a clay adopted as a reference for the extrusion potential. At the end, a cementitious component will be printed with the composition developed with low consumption of binder and the characteristics compared with a burnt ceramic product. (AU)