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Washington State University National Center for Transportation Infrastructure Durability & Life-Extension (TriDurLE)

Project Title

Effects of Combined Carbonate and Biofilm on Shrinkage Cracking in Unsaturated Cementitiously stabilized Soils Using Microcapsules.


Xianming Shi, PI

Project Description

The proposed study is on an innovative approach that couples self-healing effects of bacterial spores with sequential hydration methodology that could mitigate the development of shrinkage cracking of stabilized mixture while sustaining the development of high strength. A dual encapsulation technique, which involves a primary and secondary encapsulation of two different bacteria into a single microcapsule will be utilized. The sequential hydration which is a concept for which moisture content below optimum is provided for partial hydration and consequently minimized shrinkage cracking will be utilized. The use of dual encapsulation technique, which will allow for a carbonate and a biofilm precipitating bacteria to be encapsulated into a single capsule. The combine precipitate from these bacteria will yield a ductile composite precipitate. The coupled effects of ductile precipitate and sequential hydration will thus provide an optimum stiffness for the stabilized mixture and thus mitigate shrinkage cracking. The mixes containing bacterial microcapsules which enhance self-healing is expected to benefit immensely from the sequential hydration and lead to a novel design for cementitious stabilization.

Project Details

Project Visuals

Dr. Xianming Shi