Thermal Stress of Building Materials Containing Plasticizer Characterised by Alternating Electric Field

摘要

Paper deals with the applicability of impedance spectroscopy method to testing of cement-based composites prepared from a mix of type CEM I cement and siliceous sand, as well as by substituting 25% of sand with shredded automobile tires and by adding acrylic polymer binder (10% w/w of the polymer mass to cement mass). The monitoring of structural changes in the thermal stress is very important, for example for determining the reliability of the whole structure. Samples were intentionally degraded by high-temperature (in a temperature range from 25°C to 400°C). The primary monitored magnitudes were electrical capacitance C, the relative permittivity εr and components of electric impedance |Z|. Based on the Debye theory of dielectric the models were created, their applications and received parameters measured dielectric material is characterized and discussed the uniqueness of determining the values of model parameters. Development of electrical parameters and permittivity at each temperature areas reliably show thus structural changes and thus the structural reliability.