Heating mortar block system for melting snow utilizes electromagnetic waves of frequency 2.45 GHz and this system has a feature of quick snow removal and maintainability compared with conventional ways to remove snow. In this study, the influence of Base layer thickness on the capability of electromagnetic waves absorption was clarified and the efficiency of heating mortar block system through electromagnetic waves is improved. The followings are obtained. (1) Thickness of the base layer of sand mortar causes prominent electromagnetic waves absorption at specific frequency (hereinafter called “peak”) with periodicity. (2) It is possible to adjust the thickness of heating mortar blocks to have a peak. (3) The heating capability should be evaluated by the return loss when the sand mortar is placed under the slag mortar. [This paper is the extended version of Ito et al. (2017)]

A large-scale testing program on alkali silica reaction (ASR)-affected concrete structural members without shear rein-forcement representative of structural members found in nuclear power plants is presented. Three concrete specimens, designed to experience a free expansion rate of approximately 0.15% per year were fabricated and placed within a controlled environmental chamber (38 ± 1°C (100 ± 2°F) and 95 ± 5% relative humidity (RH)). Sixty-four (64) embed-ded transducers and twelve (12) long-gauge fiber-optic sensors provide evidence of strong anisotropic expansion and oriented ASR-induced cracking resulting from the confinement effect caused by the reinforcement layout and addi-tional structural boundary conditions. Surface cracking is not indicative of internal ASR-induced damage/expansion.