Combinatorial molecular optimization of cement hydrates.

Area of Science:

• Materials Science
• Civil Engineering
• Computational Chemistry

Background:

• Concrete is a ubiquitous building material with a significant environmental impact.
• There is a growing need for stronger and stiffer concrete to reduce material usage.
• Understanding concrete's molecular-level properties is crucial for developing advanced materials.

Purpose of the Study:

• To optimize the properties of cement hydrates, the binding phase in concrete.
• To explore a combinatorial approach for enhancing concrete's mechanical performance.
• To identify relationships between atomic structure and macroscopic properties.

Main Methods:

• Computationally generated a database of calcium-silicate-hydrate atomic structures.
• Screened structures based on three defect attributes: Ca:Si ratio and medium-range order parameters.
• Analyzed correlations between structural attributes and mechanical properties.

Main Results:

• Structural and mechanical properties strongly correlate with the calcium-to-silicon ratio.
• Cross-correlation of defect attributes revealed an extremum in the indentation modulus-to-hardness ratio.
• This extremum is analogous to optimal network connectivity in glass rheology.

Conclusions:

• A novel combinatorial method can optimize cement hydrate properties.
• Findings suggest a new pathway for enhancing nanoscale mechanical properties of concrete.
• This research contributes to developing more sustainable and high-performance concrete.