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Takeda H.,Tokyo University of Science | Suzuki H.,KUMAGAIGUMI Co.
Journal of Environmental Engineering (Japan)

Thermal behavior of a window of a building affects indoor thermal environment, especially affects heating and cooling loads significantly. And heating and cooling loads of a window is a major elemental part of whole of loads. Changes of heat transfer reflects the heat load calculation for moment to moment. The authors used multiple units of the experimental apparatus and collected data in short time intervals by the latest high speed data logger to analyze the measured data theoretically. Temperatures at 6 experimental apparatus were measured. Then, examination using the LESCOM simulation program was conducted. The measurement discovered that the indoor thermal environment was improved substantially. It was also found that figures gained from the measurement agreed well with those calculated from the LESCOM program. Climate change nowadays is saying extraordinary. The authors executed heat-load simulation with weather data of the last decade which is considered prefers to that of standard. As the results, we concluded that the simulation with the last decade is important, since it is able to evaluate standard heat-load according to annual difference. Source

Sato H.,KUMAGAIGUMI Co. | Miyazawa S.,Ashikaga Institute of Technology | Yatagai A.,Inc. DC
CONCREEP 2015: Mechanics and Physics of Creep, Shrinkage, and Durability of Concrete and Concrete Structures - Proceedings of the 10th International Conference on Mechanics and Physics of Creep, Shrinkage, and Durability of Concrete and Concrete Structures

Thermal stress in a gravity concrete dam was simulated by three dimensional FEM analyses taking autogenous shrinkage of concrete with full-sized aggregate into account. It is proved from experimental results that external concrete with blast-furnace slag Portland cement exhibits autogenous shrinkage of 130×10-6 at one year after casting, which is much larger than moderate-heat Portland cements with and without fly ash. Calculated thermal stress in upstream-downstream direction at the center of the concrete blocks near foundation rock is increased by autogenous shrinkage if concrete with large autogenous shrinkage is used. Thermal stresses in dam-axis direction at upstream and downstream surfaces are increased by the difference in autogenous shrinkage strains between internal and external concretes, if blast-furnace slag Portland cement is used. It can be said that autogenous shrinkage which simultaneously occurs with thermal strain should be taken into account in order to control thermal cracking during construction period which can adversely affect the stability, water tightness and durability of concrete gravity dams. © ASCE. Source

Takeda H.,Tokyo University of Science | Suzuki H.,KUMAGAIGUMI Co. | Hayakawa S.,Hayakawa Building Environment Laboratory
Journal of Environmental Engineering (Japan)

An opening of a building significantly affect a heating and cooling load and indoor comfort. The authors developed more precise theories analyzing optical properties of an inner installed venetian blind by introducing Radiance and behavior of the air flow by using CFD. And the theories were compared with experimental values. As a result, the calculated value is well according to experimental value. These theories were incorporated into a heat load calculation program LESCOM developed by the authors. Annual load calculations were executed by a venetian blind angle controlled every one minute. Source

AIJ Journal of Technology and Design

Measurement of prestressing force in permanent ground anchors, which was used in order to prevent the building from floating by the lift of ground water or in case of an earthquake, was carried out over the long period of time. When the prestressing force of 60 years after was presumed based on the measurement result, the effective prestressing rate was set from 0.84 to 0.95, and was around 0.9. As a result of comparing the calculated value and measurement value, it was found that the adoption value at the time of a design was appropriate. Source

Kumagai Gumi Co., Japan Atomic Energy Agency and Fibex Co. | Date: 2010-08-25

A reinforced sensor with an optical fiber woven into a fabric, comprising a fabric formed in a manner that a weft yarn is woven thereinto in a direction substantially perpendicular to a warp yarn, wherein an optical fiber is included in at least either one of fibers of the warp yarn and the weft yarn. The optical fiber may function as a FBG sensor.

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