Original paper(Vol.45 No.9 pp.1014)

Thermal properties and temperature dependence of mechanical properties of resin concretes for structural use

Hayashi Fujio; Oshima Mituharu; Koyanagi Wataru

Abstract:Resin concrete (REC) is a concrete in which aggregates are bonded with synthetic resin instead of cement hydrates in ordinary cement concrete. For the structural use of the resin concrete, the thermal and temperature-dependent mechanical properties of RECs were experimentally examined. RECs with various resin contents were prepared by using two kinds of unsaturated polyester resins and two kinds of epoxy resins with different heat distortion temperatures (HDT) and glass transition temperatures (T_g), and tested for thermal properties such as specific heat, thermal conductivity and coefficient of thermal expansion, and temperature-dependent mechanical properties such as dynamic Young's modulus, logarithmic decrement, creep coefficient and compressive and flexural strengths.
Thermal properties of RECs were very similar to those of ordinary cement concrete. Deformation and strength properties of RECs were temperature-dependent, and showed distinct inflection points in temperature in the respective properties where temperature-dependence became dominant. The inflection points were related to the HDT of the resins used rather than T_g, and were not affected by the resin content. The points can be defined as ''heat distortion temperatures of RECs''. The maximum ambient temperature must be limited to these points or lower for the structural use of RECs. Consequently, the high HDT of the resins is preferable for structural RECs.

Key Words:resin concrete, thermal property, temperature-dependent property, deformation, strength, heat distortion temperature, structural use