Concrete is an essential material for the development of the infrastructure of human society. It can usually be composed of aggregates, mineral additions and hydraulic binders such as cement. But what few people know is that the production of one of the main components of concrete, cement, is largely responsible for carbon dioxide (CO2) emissions into the atmosphere, about 8% of global emissions, which can reach 30% by 2050 if nothing is done.
In that context, we investigate sustainable alternatives for the cement industry. Our interests are based on extensive research into binders chemistry, chemical admixtures and durability of cementitious materials.
Research areas:
The concrete is used in a massive quantity, being cement, the only component produced from an industrial process, which is responsible for high environmental impact. This is because Portland cement production is responsible for a large percentage of global greenhouse gas emissions into the atmosphere, from 5 to 8%, in addition to promoting high consumption of energy and non-renewable raw materials. The emissions associated with cement production come mainly from the Portland clinker production process, which involves high burning temperatures (~1450 °C) and a high amount of carbon dioxide (CO2) is released.
Thus, the reduction in the clinker content present in cement from the incorporation of waste will result in a reduction of environmental impacts, as well as being an environmentally adequate alternative for their disposal. Another alternative is the use of alternative cements, with low clinker content, such as LC3 cement, or alternative clinkers, such as bellithium sulfate cement (CSAB), or without clinker such as geopolymers and alkali-activated materials. This area of research is aligned with one of the research pillars of the NORIE group, of which LINCE is a part, which is the search for more sustainable building materials.
The Portland clinker, the main constituent of Portland cement, consists mainly of four different mineralogical phases: C3S (alite), C2S (belite), C3A and C4AF (ferrite). The composition of the used raw materials and the production conditions of Portland cement, may confer changes in the crystalline structure (polymorphism) and in the reactivity of the main phases of this material.
In this sense, LINCE is committed to the macro, microstructural and hydration analysis of Portland cement, alternative cements and their compounds. This has major implications for the properties of cement, mortar and concrete.
The understanding of the interactions between the phases of Portland clinker and additives is not yet fully understood, due to the complexity of the chemical mechanisms involved during cement hydration in the presence of organic additives. Understanding the interaction between these systems, and their impacts on the fresh and hardened state, can bring innovative solutions to construction.
The guarantee of durability is one of the requirements expected by users of a building. The LINCE also promotes the investigation of the factors and mechanisms involved that affect the durability of cementitious materials (conventional or innovative), with the aim of extending the useful life of the final components (cements, concrete or mortars).