Increasing Concrete Magnetic Permeability with the Addition of Soft Iron Powder and Stainless-Steel Fiber Inclusions

摘要

In 2015, the USDOT launched the Smart City Challenge across America to develop innovative technology, data, and applications that can enhance the mobility of people and goods. Seven finalists were chosen: Austin, TX, Columbus, OH, Denver, CO, Kansas City, MO, Pittsburgh, PA, Portland, OR, and San Francisco, CA. There is growing momentum to build smart cities and wireless power technology (WPT) will be a critical component in this movement. There is a need, however, to improve the cost and efficiency of WPT so it can be implemented on a larger scale. Portland cement is a relatively low-cost binder, priced around $0.07/lb. (polymer binders or rubbers range from $0.60/lb. to $5.00/lb.) that can potentially be used as an encasing media to protect embedded WPT components. In this study, magnetically permeable concrete is tested at various ages to quantify the effects of iron powder and steel fiber dosage on wireless power transfer efficiency. The characteristic magnetic flux-density curve (or B-H curve) is obtained for different mixes and compared to a control concrete mix containing no metal inclusions. The mixes are used to create C-I cores used to generate the characteristic curve. The results indicate that the addition of metal inclusions can increase the concrete magnetic permeability. The improved wireless power efficiency can lead to substantial decreases in battery charging time.