Exploring the Utilization of Mineralized Fibers to Improve the Toughness of Cement

Michael Espinal, and Dr. Chelsea Heveran, Department of Engineering, Montana State University Bozeman, Culbertson Hall, 100, Bozeman MT 59717

Cement is a binder in concrete, a common building material, but it also has several problems. One is that the production of cement releases harmful carbon emissions. Another is that cement is strong but not tough. Thus, cement is very susceptible to crack propagation, especially during freeze-thaw cycles in cold winter climates. We aimed to mimic the complex hierarchical structure found in bone, which is excellent at stopping crack propagation, by creating complex mineralized shapes from cellulose fibers. We also investigated if silane-functionalized and biomineralized cellulose fibers could be engineered for toughening cement. An enzyme induced mineralization method was used to cause calcium carbonate (CaCO3) crystals to nucleate on the fiber. When implemented into the cement matrix, we expect that CaCO3 may form a strong bond to the cement. The fibers then underwent a silane coating process under vacuum to functionalize them. Functionalizing the fibers with silane is expected to cause the fibers to have hydrophobic properties which may cause the formation of complex fiber geometries. This process could toughen the cement and increase its service life, leading to a decrease in cement production. The use of optical and electron microscopy showed that the fibers were able to be successfully mineralized. Hydrophobicity tests showed that the fibers do exhibit hydrophobic properties, but they do not yet create complex geometries. This could be from the high surface tension caused by the hydrophobic silane on the fiber which caused the fibers to straighten when wet. The next steps are to implement the silane-functionalized and biomineralized fibers as a percent replacement of cement in cement mortar specimens and conduct mechanical testing on them. Further investigations into biomineralizing non-cellulose materials such as plastic waste will be conducted to explore a more environmentally friendly cement. 

Additional Abstract Information

Presenter: Michael Espinal

Institution: Montana State University Bozeman

Type: Oral

Subject: Engineering

Status: Approved

Time and Location

Session: Oral 8
Date/Time: Tue 5:00pm-6:00pm
Session Number: 821
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