Hi! I'm Elizabeth Nadelman. I am a senior in the Civil and Environmental Engineering department with a certificate in Materials Science and Engineering. I am interested in technologies that can improve the durability of construction materials, especially concrete, and I am working in the Scherer group with Lori Ruggiero to study the effects of nucleating agents on ice formation in concrete. The primary cause of frost damage in concrete is crystallization pressure, exerted when ice crystals form in the small pores of the paste. Air entrainment has been shown to alleviate crystallization pressure, as air voids provide sites where macroscopic ice crystals can nucleate without exerting stresses on the pore walls. We hope to further alleviate this pressure by introducing the nucleating agent metaldehyde into air-entrained mortar in order to promote the formation of ice crystals in the air voids at higher, less damaging temperatures.
Nucleation of ice in an air void results in suction in the liquid in surrounding mesopores. This compresses the concrete and prevents frost damage. We will introduce nucleating agents to encourage this process. The theory is explained in these papers:
“Mechanisms of Frost Damage”, G.W. Scherer and J.J. Valenza II, pp. 209
“Method of protecting concrete from freeze damage”, G.W. Scherer, J. Chen, and J. Valenza, U.S. Pat 6,485,560 (Nov. 26, 2002)
In a course-related poster session at Princeton, I presented a poster entitled, Controlling Nucleation of Ice in Air-Entrained Mortar, describing the preliminary steps of my research.