Congratulations to UNSW Engineering researcher Dr Ali Kashani who, with a team from CONTOUR 3D, and Group Architects, has won the prestigious National Award of "Excellence in Concrete" in Technology and Innovation awarded by the Concrete Institute of Australia (CIA) at the Concrete 2023 biennial conference in Perth in September.

Dr Kashani, who is based in the Centre for infrastructure, Engineering & Safety (CIES) in the School of Civil and Environmental Engineering, is a Senior Lecturer in Sustainable Concrete and 3D printing and a Churchill Fellow in Construction 3D Printing with extensive experience in research, development, and commercialisation of advanced and sustainable construction materials.

One of his research areas is 'Construction Automation' via development of novel high-performance materials and techniques for robot-aimed construction including 3D printing. His other main area of research is sustainable construction materials for the 'Circular Economy' including wastes valorisation, carbon capturing and mineralisation, low-carbon construction materials, sustainable concrete, and alkali-activated materials (geopolymers).

Dr Kashani is one of the Chief Investigators and a founding member of the University of Melbourne-led Researcher Network for Decarbonising the Building Industry (RNDBI), which has received federal government funding of $2 million, with an International Clean Innovation Researcher Networks grant announced in July 2023.

Established by the Concrete Institute of Australia in 1971, the Awards for Excellence in Concrete recognise and publicise the many significant contributions to excellence in concrete design, construction and materials in Australia. The category of Technology & Innovation includes significant contributions to the understanding or use of concrete as evidenced by research, technical publications, patent applications, new products or pieces of equipment, new techniques, design innovations, or educational activity. 

Dr Kashani, says he was thrilled to receive the award, particularly as 'we were competing against key players in academia and industry in concrete innovation.' He also acknowledged the work of his PhD student, ‘Hamid Bayat who helped a lot with this awarded project.’

Hamid Bayat & Dr Ali Kashani at UNSW Engineering CIES Construction Automation Laboratory 2021

Previously the team had won the Award for Excellence in Technology & Innovation from the NSW Division of the CIA, announced in July.  

Contour 3D in partnership with UNSW’s School of Civil and Environmental Engineering developed a new type of concrete which was used for the first 3D-printed building in the southern hemisphere.

The 3D-printed building was printed onsite in Macedon Ranges in Victoria using a modular gantry system and an extrusion-based printer (in which printing mortar is pumped through a hose and extruded from a nozzle). A layer-by-layer method of concrete placement in 3D concrete printing (3DCP) is very different to that of traditional concrete placement inside formwork. A printable concrete with excellent shape stability after extrusion and high early strength for buildability to support the weight of successive layers was designed and delivered.

The developed material had a very high early strength of about 20 MPa in one day and 28-day strength of 60 MPa. In this mix design, Portland cement was replaced with about 30 wt.% of supplementary cementitious materials (SCM) to lower the embodied carbon of the printed concrete walls. 3DCP allowed the printing of double-skin thin concrete walls (50 mm thickness) with a hollow core in between.

‘Decarbonisation in construction is not just a necessity; it is a moral imperative for our future,‘ Dr Kashani says. ‘The building industry's significant carbon emissions underscore the urgency to transform the way we design, construct, and operate structures.’

This method saved materials, costs, and construction time, in addition to a reduced carbon footprint. Glass-fibre-reinforced polymer (GFRP) rebars were used as horizontal reinforcements between the layers and fully reinforced concrete columns were integrated into the design of the building. This project demonstrated that 3DCP can lower construction costs, project duration, waste, and manpower requirements which are vital for sustainability, affordability, and freedom of design in construction.

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