Know your cement, get greener concrete
An international team of scientists has created a new database of molecular dynamics models that simulate the properties of cement in all its varieties. It’s intended to help fine-tune this component of concrete and curtail emissions in its manufacturing process.
Cement is used to bind concrete, the most-used construction material in the world and a significant source of atmospheric carbon dioxide. Its manufacturing contributes as much as 8 percent of the greenhouse gas to the atmosphere.
Investigate atomic interactions
A new database, called cemff, for cement force fields. In this case, the force field isn't an invisible barrier from a science-fiction story. It's the collection of parameters scientists use to build computer models of atomic interactions. These parameters include the intrinsic energy of the atoms in a simulation system. They are used to calculate how atoms interacts individually and collectively with their neighbors to give the material its properties.
Predictions of formulations
Application of accurate atomistic force field models allows to do computer simulation of various types of inorganic minerals present in cement. Very importantly, it helps academic and industrial researchers to draw upon many types of force fields to make reliable simulations and predictions of purpose-built cement formulations. Cemff could help industry design stronger, more durable construction materials that also curtail carbon dioxide emissions from the manufacture of more than 3 billion tons of cement and concrete a year.
Fine-tuning the material
“The publication of this database represents a milestone for the field that will increase the impact for molecular modeling in the development of new and eco-friendly cements”, says Robert Flatt, Professor at ETH Zurich and one of the scientific adviser of cemff database project. Fifteen scientists at 11 institutions of ETH Zurich, Rice University and EPFL Lausanne worked on the project. In their research, the simulation of force field models show how the component molecules in cement interact with each other. These microscopic interactions determine how well concrete performs in real-world applications and allow for fine-tuning the material to perform at its best for decades and in the most environmentally conscious way.
Reduce the carbon footprint
Cement consists primarily of calcium silicates that react with water to produce the hardened material that confers mechanical properties and durability to concrete. Nearly 60 percent of carbon dioxide emissions from cement production come from the decomposition of limestone, the source of calcium in cement. To reduce the carbon footprint, manufacturers often supplement the mix with clays, waste materials like fly ash and recycled materials.
In line with trend towards big data
These all influence the mechanical characteristics and resilience of the product; that is why there is a need for simulations at nanoscale that let manufacturers test mixes for strength and durability even before making real cement. “This unified database is in line with the current trend towards big data and predictive computational materials science,” says Rouzbeh Shahsavari, assistant professor of civil and environmental engineering and of materials science and engineering at Rice University.
