Climate change continues to intensify the hazards we, and our civil infrastructure, experience. The 21st century has marked an increase in frequency and severity of flooding, hurricanes, wildfires, and extreme temperature events. Our new dynamic environment, with concurrent risks from multiple natural sources, needs engineering solutions to enable multi-hazard risk reduction efforts. This project investigates using polymers as an adaptable solution to simultaneously tune the behavior of reinforced concrete structures for multiple hazards. This differs from standard practice, where the response of a structure is determined based on a single load scenario. Polymers that exhibit strain-rate- and time-dependent properties are introduced to tailor the bond characteristics between the rebar and concrete in critical regions, producing improved overall structural performance when considering a multi-hazard environment. Through standard testing, polyurethane was chosen as the polymer based on compression and shear modulus results at different strain rates. To investigate the influence of polyurethane layer thickness, shape, and strength on the bond behavior between rebar, polyurethane, and concrete, cylindrical concrete specimens were tested under cyclic displacements at three different strain rates. The specimens were constructed by casting concrete between a central corrugated duct and a steel tube. Rebar was aligned along the central axis and polyurethane was cast between the steel duct and rebar. The testing data was used to determine the effective bond stress on the rebar as a function of material duct size and shape. The bond was shown to vary based on the geometry, induced strain rates, and strength of the polyurethane layer. This is markedly different than in current practice where the bond stress is assumed to be constant. The results of this project will help equip structures to adapt to multiple worsening climate change driven hazards, reducing the risk of building failure under extreme loading therefore improving community safety. 

Indoor air pollution is a major issue in urban homes, where hazardous volatile organic carcinogens (VOCs), including formaldehyde, can accumulate in the air. This study aims to investigate the potential of genetically modified Epipremnum aureum (pothos ivy) in reducing indoor air pollution by degrading formaldehyde into the non-harmful chemical formate. The study will use a flow-through bioreactor and spectrophotometer to measure the rate of formaldehyde degradation. Preliminary work includes creating standard curves of different formaldehyde concentrations and analyzing them using a spectrophotometer. Then, during the experiment, a stream of air containing formaldehyde concentrations typically found in homes will be exposed to three experimental groups: no plant, wild-type plant, and genetically modified plant. The genetically modified plants are engineered to express the enzyme formaldehyde dehydrogenase (FALDH) cloned from the bacterium Brevibacillus brevis, which oxidizes formaldehyde to formate. Any remaining formaldehyde will be collected in an effluent trap and derivatized with DNPH for analysis. Its amount will be measured using a spectrophotometer to determine the percentage of removal. The genetically modified pothos ivy is expected to exhibit a higher rate of formaldehyde degradation than the wild-type plant, owing to its FALDH enzyme. The results of this research aim to provide support for the use of plant-based strategies in combating indoor air pollution and improving human health.