Dielectric properties of densified hardened cementitious materials

✍ Scribed by M. Perez-Pena; D.M. Roy; A.S. Bhalla; L.E. Cross

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 735 KB
• Volume: 16
• Category: Article
• ISSN: 0008-8846
• DOI: 10.1016/0008-8846(86)90019-0

✦ Synopsis

Relative permittivity (K') and loss factor (tan D) of densified hardened cementitious materials with w/c=0.20 and heat treated to 500°C prepared with type I, type III, and a special microfine high silica content(MC500) cement have been compared as a function of temperature and frequency.

These K' and tan D values were found to be considerably lower for materials with microfine silicate cement than those with portland cements. Activation energies (Q) and relaxation times for the loss mechanism values were related to an ionic jump relaxation process.Lower K' and tan D values have been measured for cement/polymer composites prepared with a methyl cellulose polymer and a lower w/c ratio of 0.17. The relative permittivity and loss factor of'materials with a 60 vol. % of silica microspheres prepared with the silicate cement ranged from 5.4 to 5.1 and from 0.035 to 0.012 respectively.