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Distributed optical fiber temperature sensing technology has the potential to be used to determine the cast-in-situ pile integrity. This study proposed an arrangement of optical fibers for obtaining the pile integrity in situ, and it provided a calculation model for the temperature distribution. A model pile was constructed with the dimensions of 1.5 m × 0.5 m × 0.5 m. The fibers were implanted parallel to the center axis of the pile with a spacing of 0.04 m. The heat conduction area generated because of the heating of the fiber in the center of the pile was tested. The test results indicated that the heating conduction area was limited for certain heating powers. Furthermore, for the heating conduction area and heating power, care must be taken while arranging the optical fibers in the piles to determine the integrity.

Composite materials, which consist of at least two components (i.e., reinforcement and matrix), have been widely applied in modern industries such as aviation, construction, and automotive engineering. The interphase between reinforcements and the matrix is critical to the overall performance of resulting composite materials because it transfers stress from the matrix to reinforcements. In this chapter, various reinforcement and matrix materials and their composites are introduced. The mechanisms of forming interphase between reinforcements and matrices are elaborated based on the adhesion theory. Several conventional interphases of composite materials, such as fiber/metal, fiber/ceramic, and fiber/polymer interphases are discussed in detail. The microstructures of the interphase and their correlation to resulting mechanical properties are also presented. Finally, future research trends in this field are summarized for the prospects and advances in composite interphase.

The equivalent plasticity strain (EPS) of snow-melting heated pavement concrete that exposed to inner elevated temperatures is analyzed with finite element simulations. An optimal mix proportion of the concrete with high thermal conductivity was obtained through mechanical and thermal experiments, which helps facilitate reducing the damage in snow-melting pavement. A three-dimensional (3D) finite element model is developed based on the concrete damage plastic (CDP) model with parameters. The EPS is considered as the performance evaluation index for damage in snow-melting heated pavement concrete. Based on the results of finite element simulations, the EPS of snow-melting heated pavement concrete that exposed to inner elevated temperatures was analyzed under different pavement structures and external conditions. Furthermore, two EPS prediction models were proposed: the one is for EPS and the inner elevated temperature, the other is for EPS and five key factors. The outputs of 3D finite element simulations were verified by an experiment result. It indicated that numerical results agreed with experimental results very well. A prediction and evaluation method of damage for snow-melting heated pavement concrete was established as well.