Broken glass is of great use!Researchers use recycled glass to develop new eco-friendly 3D printed concrete

Introduction: Traditional concrete formulations often rely on natural river sand as the main ingredient, but this resource is gradually becoming a scarce commodity, and its use often has a destructive effect on the environment. Therefore, scientists have been trying to find alternative materials for natural river sand in order to realize the sustainable development of concrete production.

Researchers at RMIT University have developed a new eco-friendly3D printingConcrete material, the special feature of this material is that it uses recycled glass as aggregate.The research team believes that by choosing to use recycled glass particles as a substitute for river sand,
architecture
Promote the concept of circular economy in the field, and will3D printingLinked to the benefits of sustainable concrete production.
Interestingly, the team also investigated the influence of glass particles on the flexural strength and crack propagation characteristics of concrete.They are sure, relying on3D printingThis new formula can actually also provide mechanical performance benefits.

△Royal Melbourne Institute of Technology3D printingConcrete structure-90° cross portrayal angle. The photo is from RMIT University.

Replace river sand with recycled glass

The manufacture of concrete requires a mixture of Portland cement, water and some aggregates such as sand and gravel. Aggregates are critical because they act as binders for concrete mixtures. Without them, water-based cement mixtures cannot be maintained well and are not suitable for construction applications. Aggregate can also be used as a filler for mixtures to reduce the porosity of concrete and make the product stronger.
One of the most widely used aggregates in construction is natural river sand, which is extracted from river beds and banks. Although it is easily available on the market, excessive use of river sand can have extremely harmful effects on the local ecosystem living in and around the river.

The RMIT team believes that this concrete3D printingThe sustainable development concept of the method is embodied in the use of recycled glass instead, because the chemical composition and physical properties of the glass are not much different from the original sand. According to data from the U.S. Environmental Protection Agency, we humans produce millions of tons of glass waste every year, and reusing part of it in the construction field can greatly reduce waste in landfills.

△If traditional concrete mixtures are to be used for load-bearing applications, gravel and sand are required as aggregates. Photo from Parklea Sand and Soil.

The influence of glass content on concrete performance

So, how does RMIT’s glass-based mixture compare to traditional concrete?The team prepared five different glass filling mixtures with different glass to sand ratios and used each formula3D printingA set of concrete test samples.
The flexural strength of these structures is characterized by a three-point bending test, while X-ray microcomputer tomography and scanning electron microscopy (SEM) are used to evaluate the microstructure of the specimen. This allowed the research team to analyze the pore size distribution and crack propagation path in the sample after the test.

The results show that the integration of recycled glass particles has increased3D printingThe porosity of the sample. This is more pronounced when using coarse glass particles than fine glass particles. Using X-ray imaging, the researchers were able to show that the main component of crack propagation is the glass particles present in the voids.

Nevertheless, after adding glass particles,3D printingThe flexural strength of the sample actually increased by 25% to 33%, but only when the beam span was perpendicular to the printing direction. When the beam span is parallel to the printing direction, glass particles have been found to reduce the bending strength by 8% to 20%.

Therefore, the university’s research team determined that as long as the printing direction is carefully controlled, recycled glass can be used as a suitable substitute for river sand for sustainable concrete3D printing.

More details of the research can be found in the paper entitled “3D-printed concrete with recycled glass: Effect of glass gradation on flexural strength and microstructure”.

Links to related papers:https://www.sciencedirect.com/science/article/abs/pii/S0950061821032992?via%3Dihub

△Filled with glass particles3D printingSEM image of concrete. Picture from Royal Melbourne Institute of Technology.

Earlier this year, scientists at Swinburne University of Technology and Hebei University of Technology conducted a similar study to convert construction waste into sustainable3D printingConcrete. Use recycled concrete aggregates,ceramicsGranules and desert sand, the team was able to formulate a low-cost extrudable building material in three different granular grades.

Elsewhere, researchers from Tongji University recently published the results of a study exploring the feasibility of using recycled fine aggregate (RFA) in 3D mortar printing. The research seeks to understand more accurately the buildability of 3D concrete printing and how the use of recycled and discarded materials affects the manufactured structure.

(Editor in charge: admin)

Broken glass is of great use!Researchers use recycled glass to develop new eco-friendly 3D printed concrete

0 Comments for “Broken glass is of great use!Researchers use recycled glass to develop new eco-friendly 3D printed concrete”

Leave a Reply Cancel reply