18 August 2021

Nanoengineered bio-concrete as future materials

By Dr Chin Mei Yun, Amelia Chai Pei Sze & Ts. Dr Hj. Muhammad Khusairy bin Bakri

Concrete has been relied on for decades as the most widely used building material due to its durability, flexibility, and strength. In the field of concrete production and application, significant progress has been made over time. Concrete is available in the market in a variety of grades, compositions, and energy efficiency ratings, making it more accessible to everyone.

However, one of the most revolutionary concrete features was developed by a Dutch researcher and microbiologist Hendrik Jonkers. Jonkers mildly modified the composition of standard concrete by injecting a biological ingredient that gave it self-healing properties. This has resulted in producing concrete called bio-concrete.

Bio-concrete is proving to be a game-changer in the construction industry. This amazing material can ‘heal itself’ from cracks and breakage, thus, ease the builders’ burden in completing construction and dealing with costly replacements. Bio-concrete can contribute to structural stability and durability by decreasing the likelihood of a building collapsing.

So, what exactly is this bio-concrete and how does it function? Bio-concrete is a cutting-edge building material that can self-heal fractures. It contains bacteria that can produce limestone under certain conditions.

When a crack appears in the bio-concrete, the bacteria become activated, allowing limestone to form and heal the crack. As a result, the bio-concrete becomes more resilient and environmentally friendly. In contrast, less limestone would need to be mined to produce cement for concrete production and building repairs would cost less money.

In bio-concrete, clay pellets are also used as an additional component. In these pellets, bacteria spores are fused with calcium lactate. Limestone is formed when external elements (such as air and water) interact with bacteria in a concrete crack. This limestone is what heals the mortar by ultimately filling in the gaps.

Bio-concrete can be used in real-world situations because bacteria can survive for many years without losing their active properties. When a crack appears inside the clay pellets, it is essentially inactive and is triggered by external factors.

Bio-concrete can benefit the construction industry. Architects, contractors, engineers, and other stakeholders were intrigued by the study on self-healing concrete, which piqued their interest in how bio-concrete could be used to streamline daily construction operations. Is bio-concrete on its way to becoming the next big thing in construction?

The features of this material make it a front-runner for widespread use in the coming years. One of the most useful applications of bio-concrete is to fill minor gaps in bigger concrete slabs, cracks in bridges, and other buildings that if left without repair, would cause extreme damage over time.

Bio-concrete can fill cracks up to 0.8 mm or the size of an ant, preventing the cracks from becoming larger and avoid significant structural damage. Because of their flexibility, bio-concrete is useful for bridges, houses, tunnels, and other buildings.

The material’s wider use may open-up a slew of new possibilities in chemistry, microbiology, and construction. Not only can we save money on repairs, but we can also experiment with new designs and benefit from more reliable systems. The benefits of bio-concrete extend beyond its cost as it is both environmentally friendly and long-lasting.

This solution also helps industrial and residential construction companies minimise their carbon footprints by lowering greenhouse emissions. As lower maintenance is needed, less materials are required for repair works, hence, releasing less greenhouse gases. The future of our sector lies in sustainable construction, and bio-concrete is at the forefront of that movement.

In long operating cycles, bio-concrete was recently put through endurance tests to see how harsh and strong it is. According to the research conducted, the compound will last more than a few decades in its natural state. This implies that clay pellets in the biochemical mixture can withstand a wide range of temperatures and physical conditions.

Bio-longevity concrete is a game-changer because it can be used in so many ways. In addition, a bio-concrete researcher is developing a new method for encapsulating bacteria in concrete mixtures. This will reduce manufacturing costs and at the same time, increase the usefulness of this ground-breaking technology.

The construction industry does not seem to be slowing down. Bio-concrete and sustainable construction have a bright future, and businesses should not miss out on this innovative construction alternative.

Dr Chin Mei Yun is a lecturer, and Amelia Chai Pei Sze is a PhD candidate at Swinburne University of Technology Sarawak Campus. Ts. Dr Hj. Muhammad Khusairy bin Bakri is a Swinburne alumnus. They can be reached via email at mychin@swinuburne.edu.my / apchai@swinburne.edu.my / mbakri@swinburne.edu.my