Office of Undergraduate Research

Superhydrophobic Engineered Cementitious Composites

This research project aims to develop superhydrophobic engineered cementitious composite (ECC) material to replace normal concrete and achieve a service life of 120+ years. The principal objectives of the project are to: 1) Develop an ECC material design with polyvinyl alcohol (PVA) fibers that can provide the deformability required in critical regions of highway bridges to allow heavy freight traffic without brittle damage or undesirable cracking; 2) Define proportioning and dispersion of hydrophobic (PEHS/PMHS) admixtures needed to achieve optimal volume, size and distribution of air voids in the hardened paste to provide long term durability for the concrete; 3) Achieve superhydrophobic hybridization with coating of air void surfaces by hydrophobic admixtures/particles; 4) Use the PEHS/PMHS admixtures to control bond with the PVA fibers and achieve controlled fiber pullout rather than fracture if an excessive deformation demand occurs in the highway bridge due to bridge overloads; 5) Use a controlled air void structure in the hardened concrete to develop preferred fracture modes under bridge overloading; 6) Evaluate the combined effects of PVA fibers, siloxane-based admixtures, superplasticizer, and supplementary cementitious materials (SCMs) in ECC concrete; 7) Evaluate the durability aspects of the superhydrophobic ECC.

Tasks and responsibilities:

Task 1 Develop the ECC with improved ductility and strain-hardening response; Task 2 Produce and test ECC with superhydrophobic admixtures and SCMs; Task 3 Investigate the durability of developed ECC Hourly lab assistants will be responsible for lab work, including testing of concrete and cementitious materials. These students will also be responsible for the evaluation of test data such as mechanical and durability properties, materials characterization, durability testing, and evaluation of data.