Fast Setting Binders for Application in 3D Printing of Bio-Based Building Materials

Maris Sinka,Diana Bajare,Aleksandrs Korjakins,Genadijs Sahmenko,Jelizaveta Zorica

doi:10.3390/su12218838

Abstract

The construction industry is one of the largest emitters of CO2 because the production of traditional building materials is highly energy-intensive and uses considerable amounts of raw materials. This research aims to decrease the negative environmental impact of the construction industry by providing biocomposites with a low environmental impact due to their bio-based components and efficient use of the materials through 3D printing. Agricultural waste products—hemp shives—are used in these materials as a filler together with three different types of fast-setting binders—magnesium, calcium sulphoaluminate (CSA) and those that are gypsum-based. The study determines the setting time and compressive strength of these binders, as well as the formation of biocomposites of different densities for different applications; extrusion tests and preliminary life cycle assessment (LCA) are also performed. Results show that biocomposites with hemp shives and fast setting binders have a possible application in 3D printing due to their shape stability and buildability, as well as relatively high compressive strength, which allows for load-bearing use at high densities and thermal insulation use at low densities, although printability at low binder content remains a significant challenge. Preliminary LCA results show that CSA and gypsum binders have the lowest environmental impact from the binders considered.

Highlights

In recent years, world leaders have signed several agreements committing to limit CO2 emissions, for example the Paris Agreement ratified by the EU in 2016 [1]
Looking at the setting time, it can be seen that the MPC binder sets most rapidly in eight minutes, followed by the BG binder and calcium sulphoaluminate (CSA) binder which sets in 34 min
This study demonstrates the potential of using various alternative fast-setting binders and bio-based fillers to create biocomposites that can be used in 3D printing of buildings and building materials in various applications with reduced environmental impact

Summary

Introduction

World leaders have signed several agreements committing to limit CO2 emissions, for example the Paris Agreement ratified by the EU in 2016 [1]. In order to achieve these commitments, the EU has several environmental targets—for example the Energy and Climate framework 2030 aiming to reduce the greenhouse gases by 40% and increase energy efficiency by 32% by 2030 [2], or the 2050 long-term strategy that aims for climate-neutrality by 2050 [3]. These efforts do not contribute significantly to reducing the global CO2 level, as it is still on the rise and has exceeded 410 ppm, moving closer to 450 ppm, which is viewed as a boarder to keep global temperature rise under 2 ◦C. The increasing demand for building materials has called for an alternative and resource-saving production and raw material sourcing method

Objectives

Discussion

Conclusion