This project developed a new class of ultra-high performance, multifunctional concrete using emerging two-dimensional (2D) materials. The core strategy lies in mixing ultra-thin exfoliated nanosheets of 2D materials such as hexagonal boron nitride, hBN, as small as few atoms in thickness, in the bulk concrete. hBN exhibits several exotic properties (ultrahigh mechanical and thermal properties, chemical inertness, hydrophobicity, etc) that are highly desirable for a complex matrix such as concrete. These features, combined with the double surface area per mass of hBN sheets - compared to conventional 1D fibers - can act as template (seeds) to regulate the hydration processes and maximum contact between the sheets and the matrix, thereby providing an effective reinforcement from the bottom up.  We studied several different routes to investigate the degree of exfoliation and reduction in size of hBN (to increase surface area) as well as their functionalization and water solubility in effectively mixing them in concrete. We synthesized various concrete coupons with variety of weight percentages of 2D materials. Notable among our results are the compressive strength of the concrete cylinders that can increase by >71%, with only a very small fraction of the 2D materials. Furthermore, we found the tensile strength of the concrete samples increases by >100%. The measured durability properties of the concrete samples also showed ~35% increase, compared to the control sample devoid of hBN. Following discussions with TxDOT and implementation requirements, we determined a patch/repair job on a surface of a road/highway to be a good starting point for field testing. We examined the compatibility of our formula with common accelerators such as CaCl2 and found no negative cross-effect between our technology and common accelerators while exhibiting compressive strength of 1800 psi in only ~5 hours, making the technology suitable for rapid construction and/or maintenance in transportation applications.

The final report is available.