Upgraded Concrete to Reduce Carbon and Achieve Higher Speed and Efficiency Digital Control of Transportation to Ensure Safety

The construction industry is constantly looking for ways to play its part in sustainable development. As concrete is the main material used in most buildings and accounts for 8% of the world's CO2 emissions, the Global Cement and Concrete Association (GCCA) has stated its aspiration to achieve net zero emissions by 2050. Construction Industry Council (CIC) is committed to promoting sustainability in the industry and encouraging the industry to try to achieve carbon neutrality with negative carbon technologies. Earlier, Ir Thomas HO, Chairman of the CIC, together with Mrs. LO LEE Oi-lin, our Council member, and Ms. Fay SIU, the Chief Executive of the Association for the Rights of Industrial Accident Victims (ARIAV), visited one of the concrete batching plants of Gammon, to explore how concrete can be upgraded to reduce carbon emissions while improving speed and efficiency, and to ensure the safety of concrete truck drivers through digital technology.

The Fast and Accurate Concrete Sensor

Traditionally, the maturity of concrete blocks is measured by either Cube Crushing or Rebound Hammer. While the former is destructive to the building and creates a lot of waste, the latter is extremely demanding with positioning and angle, which affects the accuracy of results. The Concrete Sensor, which was introduced by Gammon from the UK 4 years ago, was not only as small and light as a strawberry, but also saved time and made the projects much easier. It could be attached directly to the steel bars and poured into the concrete as usual, allowing the sensor to detect the maturity of the concrete with a temperature measurement. The results could be sent to the mobile phone in real-time, so there’s no need to wait for the Cube Crushing report before continuing with the rest of the building process. In addition, the artificial intelligence of the Concrete Sensor will alert you when the concrete is too strong or too weak. Last year, the Buildings Department started to recognise the results of this new measurement method. Compared with the traditional Cube Crushing test, which requires 14,000 bricks for a project, the Concrete Sensor can save 18 tonnes of CO2, which is a huge step forward in environmental protection, social responsibility, and governance (ESG) for buildings.

One of the construction projects at LOHAS Park in Tseung Kwan O has been trialed with the Concrete Sensor. If concrete is poured in the traditional way, it usually takes more than 160 hours before the concrete is strong enough for the next process. With the new method, it can be reduced to 100 hours. The average construction project takes five days to complete a floor, but with the new technology, it can be reduced to four days. For a 23-storey building, a whole month can be saved in the process, that’s a whole new level in speed and efficiency. Some projects in Singapore are already using third-generation sensors, which can detect structure tilting or vibration. Moreover, the battery of the Sensors can be replaced, so they can be used for a long time.

CIC member Mrs. LO LEE Oi-lin hoped that the new generation of Sensors will be able to measure the corrosion of the steel bars, thus informing the owner and the property management office at an early stage. Mr. Andy Wong, General Manager of Digital G, estimated that a 30-storey project would require about 300 sensors, at a cost of only 0.01% of the whole project. Ir Thomas HO, Chairman of the CIC, praised the technology for saving time and reducing carbon emissions while managing the cost, making it worthwhile for the industry to follow suit.

Turning 'Carbon' into Energy

The engineering team started using CarbonCure technology last year to recover carbon dioxide and add it to the concrete for mineralization. Carbon dioxide could be combined with calcium cement and turned into calcium carbonate, which was permanently stored in the concrete, thus increasing the strength of the concrete and reducing the use of cement materials by 5%. It would also minimize carbon dioxide emissions to the atmosphere. The engineering team recycled carbon dioxide in the Mainland and stored in a metal pressure cylinder in the Tuen Mun plant. The control room would then give a signal, to inject the carbon dioxide into the concrete as a mixture of gas and snow, reducing carbon and protecting the environment in the process.

Artificial Intelligence for Temperature-Controlled Concrete

The concrete produced at the plant is normally sent to the site with ice pellets, in order to maintain a specified temperature. Before the invention of Ice Optimisation Content AI control system, the engineering team relied on their own experience to roughly estimate the number of ice pellets required per truckload. But now it is possible to use the system's big data to calculate the amount of ice needed, to maintain a specified temperature based on the local weather and raw material temperature. The system keeps track of the condition of the concrete as it arrives on site, saving up to 25kg of ice per cubic meter of concrete and over 17,000 tonnes of ice a year, which is a clear benefit in terms of quality monitoring and sustainable development.

The Control Room as the Heart of Logistics

ESG cannot be achieved by one application alone, it is equally important in managing the logistics team. The control room inside the concrete batch plant is the heart of the plant. By sitting in front of the control panel, the GPS can detect the speed of the concrete truck and the road speed limit, updated every 30 seconds. If speeding is detected continuously, an alarm will be issued inside the vehicle. The supervisor will be notified by SMS or email so that he/she can call the driver immediately, to remind the driver and understand the situation. When the truck arrives at the site, the screen of the control room will display which concrete is being poured and when the task will be finished, all at a glance.

Regular Driver and Vehicle Inspections to Prevent Accidents

Gammon Construction requires regular check-ups on its drivers and vehicles. There are mandatory annual medical checks for its drivers. Holidays are provided, and schedules are carefully managed to prevent excessive hours of work. Specially designed restrooms and bathrooms are available for drivers to clean up, rest and stretch. To revisit safety knowledge, drivers are also required to participate in driving attitude tests and different workshops. The braking system tests are performed every two to three months for transport vehicles. The team also reminds its drivers to avoid traffic blackspots as far as possible. With this multi-pronged approach, the accident rate has declined recently. Ir Thomas HO, Chairman of the CIC hopes that the whole industry can refer to this Code of Practice.

From production to transportation to usage, concrete plays an important role in the life cycle of buildings and structures, and significantly impacts sustainable development. The CIC has introduced green product certification for the industry, over 800 products have been certified in 28 product categories, of which more than 500 are concrete-related. CIC hopes by choosing more environmentally friendly materials and products, the industry can work together to build a sustainable future and create a liveable city.