1. Problems
Concrete is ubiquitously applied in the built infrastructure with a worldwide growing consumption of over 30 billion tones each year. The concrete construction industries all over the world face enduring challenges as attempting to curb the carbon emissions by 2050. As an essential component of concrete, the Ordinary Portland Cement (OPC) production requires calcination of the raw limestone and clay materials at a high temperature, which releases significant amount of carbon dioxide (CO2) which is responsible for 8-9% of the global anthropogenic CO2 emissions. Because up to date, no alternative cementitious materials on the horizon that are capable of completely substituting the OPC, the production of OPC is forecast to double in the next 30 years to meet the rising global demand. Significant research efforts were targetd at enhancing the performance of OPC-concrete materials to meet the global CO2 emission goal using different organic/inorganic nanomaterials. However, the broad industrial application of these nano-modified concrete materials is currently facing serious challenges for two major issues: first, these nanomaterials exhibit weak dispersion capacity in water solution and cement paste, as such they tend to agglomerate at high concentrations, leading to the formation of micro defects and nonhomogeneous microstructure development in concrete. Second, the nanomaterials are extremely expensive and energy intensive to produce, and particularly pose significant environmental, health and safety risks. Therefore, there is an urgent need to develop low-cost and low carbon foot-print construction materials to enhance the sustainability of the built infrastructure.
2. Importance
The project proposed a new concept of a green construction material with the objective of helping the construction sector to drastically cut its carbon emissions associated with the consumption of Portland cement (OPC), one of main contributors to anthropogenic carbon dioxide (CO2). The proposed construction material combines intelligent bio-nanomaterials with OPC to produce multifunctional concretes that out perform current concrete at lower OPC dosages, thus lower carbon foot-print. The bio-nanomaterials are in the form nano platelets derived from carrot and sugar beetroot recovered from waste produced the food industry. Unlike current nano materials, the intelligent bio-nanomaterials are low-cost, green and renewable and are highly compatible with existing concrete materials. Their addition to OPC not only enhances the performance of concretes but also induces new functionality in concrete structures that enables to monitor their own health and detect structural damage at early stage, thus improving their resilience and sustainability. It also enbale concrete structures to act as green electricity generation that can be used to power internet of things in smart cities.
3.Overall objectives
The aim of this project is to develop new intelligent cementitious nanocomposites for multifunctional built infrastructure by combining OPC with cheap and reeable bio-based 2D nanomaterials synthesised from root vegetable such as carrot and beetroot waste streams produced by the food processing industry. The microstructure and the molecule model for the biomaterial is shown in Fig 1 in the attached images. These novel cementitious composites are not only superior to current cement products in terms of mechanical and microstructure properties, but also use smaller dosages of cement, thereby, significantly reducing both the energy consumption and CO2 emissions associated with cement manufacturing. The novel cementitious composites also exhibit a piezoelectric effect, enabling concrete structures to perform multiple functions such as: 1) self-monitoring mechanism to sense, feel and diagnose impending catastrophic structural failures and 2) green energy production by converting mechanical energy into inexpensive and readily available electrical energy.
