This work investigated the application of mycelium as a potential binder for pavement infrastructure; the focus was on assessing the maturity level of mycelium-bound aggregate specimens. A review of the technical literature revealed that none of the existing methods are transferable to the proposed application. Thus, a new non-destructive laboratory setup was designed and built for this purpose; it is a device for producing shallow depth-sensing indentation. The underlying idea is that the specimen’s indentation stiffness increases as the mycelium matures, and stops evolving once 100% maturity is achieved. Thus, by performing periodic indentation tests during incubation, it becomes possible to observe and quantify the progression of maturity. The work included a demonstration of the setup, with specimens periodically indented over a two-week incubation period. As expected, the average indentation stiffness increased over time. The indentation results were independently validated against CO₂ production rate measurements. Overall, it is concluded that shallow depth-sensing indentation is a viable approach for assessing the maturity of mycelium-bound aggregate specimens. Two additional advantages of the approach are: (i) testing can potentially be done outdoors, and (ii) indentation results can produce inputs to mechanistic pavement models.
Yin et al. (Tue,) studied this question.