New formwork research addresses the challenges presented by complex geometries in concrete construction, which remains dominant but inefficient in terms of material waste.
Formwork is an integral part of concrete construction and amounts o a substantial proportion of costs, estimated at between 35 to per cent or more of the total cost of a concrete structure.
It is used to provide either temporary or permanent moulds when concrete is placed, with temporary formwork removed when the concrete has hardened and permanent types integrated as part of the structure.
Current methods face high costs and material demands, particularly when it comes to traditional formwork systems that are often single-use.
Digital engineering tools can provide realistic 3D visualisations of temporary formworks, with new innovations such as 3D printing, finite stress analysis, virtual reality and augmented reality, enabling multiple advantages from concept design to delivery.
Using digital technology in formwork design and management can also help improve the overall sustainability of concrete construction by optimising material use and reducing waste.
Formwork modelling incorporated with building information modelling (BIM) software allows for better coordination, decreasing the risk of damage or wasteful errors.
Reducing formwork waste can also be achieved through careful planning and design, using adjustable formwork systems, and implementing quality control measures.
Moreover, as the use of alternative binders in concrete becomes more common, how these affect engineering processes around form pressure, form stripping, and the overall design of formwork should be thoroughly considered.
Alternative binders can provide substantial opportunities to reduce the environmental impacts of concrete production, but they can also affect the various concrete processes, such as setting and hardening.
Recent studies have introduced innovative and zero-waste approaches using recyclable and reusable digitally fabricated formwork made from waste materials, or producing complex, ultra-thin concrete prototypes with prefabricated formworks, while meeting high standards for surface quality and structural integrity.
These breakthroughs highlight the viability of sustainable practices in achieving efficient, material-efficient, and cost-effective construction solutions while reducing the construction sector’s environmental impact.
A paper published last year by Swiss researchers emphasised earth – with its millennia-old role in architecture – offered new potential as a reusable, biodegradable, and low-energy formwork material.
The researchers said: “From robotically scored clay slurries to granular beds of waste aggregates, earthen systems challenge the dominant paradigms of precision casting, favouring contextual, site-responsive, and regenerative processes.
“Unlike industrial shuttering, they can be reconfigured, reused, or reintegrated into the landscape with minimal processing. “Digitally or manually shaped, they propose a radically different material logic formwork as a circular medium for sustainable construction.”
The paper presented a series of experimental approaches to formwork, including 3D-printed earth fillers for concrete slabs and scored slurry layers that crack into material-optimised casting geometries.
It also made some initial investigations around reconfigurable granular formworks that use crushed bricks, gravel, sand, and construction waste while being shaped by manual or robotic techniques.
While these systems offer compelling environmental and formal potential, the researchers noted their adoption within professional construction would probably remain marginal.
They explained that the barriers were not merely technical, but reflected deeply embedded expectations about how building processes should function, how materials are regulated, and how architecture is aesthetically valued, particularly on the surface.
They noted four main obstacles: construction timelines and process incompatibility; regulatory constraints and the rigidity of norms; insurance, certification, and risk aversion; and aesthetic expectations and material expression.
The researchers said: “These barriers reinforce a systemic tradition in which the formwork is expected to be precise, disposable, and invisible – rather than adaptable, reusable, and expressive.
“For circular construction to truly take root, even the temporary phases of a building must be reimagined as opportunities for material intelligence.”
A different project undertaken by researchers from ETH Zurich in Switzerland showed it was possible to achieve structural stability while using less concrete and steel, with a foldable formwork system for vaulted concrete structures that can be reused and requires fewer resources to produce.
The researchers aimed to find a simple and robust solution that used strength through geometry, not only to optimise the final structure but also the formwork itself.
Their solution reduces material usage and makes the entire process more environmentally friendly, and could be produced and assembled without specialised knowledge or high-tech equipment.
Formwork for non-standard concrete shapes typically requires digital fabrication, creating barriers for sustainable concrete construction in developing countries, where the need for new buildings is especially high.
The innovation at the heart of the new technique is bending-active structures, where elastic materials are bent like thin and long splines or plates of wood, with the resulting deformation creating stability and allowing for curved, lightweight structures.
A key feature of the system is its zigzag-like arrangement of wooden strips, with the ribbing providing additional stiffness without significantly increasing the overall weight.
Non-standard geometry in formwork is typically single-use, and its manufacturing process generates considerable waste.
Another study published in 2023 investigated a manufacturing process for concrete structures that combined 3D printing of clay formwork with incremental concrete casting, a novel technique that provided recyclable and easily demoldable formwork for building-scale bespoke concrete elements.
The researchers said the technique sought to challenge conventional methods and materials for 3D-printed formwork, demonstrating the ability to reduce the environmental impacts of concrete construction without compromising complexity and time efficiency.
They explained that the non-standard geometries created through the process were challenging – if not impossible – to fabricate using other advanced concrete casting technologies, and its viability as a sustainable construction technique was enhanced by how easily the material was reused and recycled.
The researchers added: “Using clay reduces the carbon footprint of creating complex forms by minimising material waste and providing recycling opportunities, [while] the developed incremental printing and casting process allowed previously unachievable scales by having the clay and concrete work together.
“The technique also enabled the integration of openings and overhangs, which was made easier through the effortless demolding process, avoiding the constraints of concrete and polymer formwork extrusion.”