Entity

Time filter

Source Type


Lin W.,Waseda University | Yoda T.,Waseda University | Taniguchi N.,Maebashi Institute of Technology | Satake S.,Taiheiyo Materials Corporation | Kasano H.,Waseda University
Journal of Constructional Steel Research | Year: 2014

Structural repairing or maintenance technique has been a hot issue in recent years due to the increasing aging problems of old railway bridges. A strengthening method for welded joints in old steel railway bridges by integrating the rapid hardening concrete, rubber-latex mortar, and reinforcing bars is introduced in this paper. The purpose of the present study is to investigate the mechanical performance of the strengthened connection joints in old steel railway bridges. Depending on the locations of the concrete and possible loading conditions, the joint needs to sustain both negative and positive bending moment, therefore, two experimental plans were employed. The static loading tests on the steel joints before and after strengthening were performed to confirm the effects of the present strengthening method. Moreover, three-dimensional FE models were built to make a comparison study between the strengthened and original steel joints. Load versus deflection relationship and strain development process on the web of the joints were measured and compared between the original joints and the strengthened joints. Both experimental and numerical results indicate that the present strengthening method can greatly enhance the stiffness and reduce the stress levels of steel joints, resulting in the extension service life of aged steel railway bridges. © 2013 Elsevier Ltd. Source


Nagashio Y.,Taiheiyo Materials Corporation | Masuda Y.,Utsunomiya University
Journal of Structural and Construction Engineering | Year: 2010

This study discusses the drying shrinkage and the carbonation of Ecocement with ground granulated blast-furnace slag, as compared with those of Ordinary portland cement with ground granulated blast-furnace slag. As a result, The drying shrinkage of Ecocement with ground granulated blast-furnace slag had become small, as compared with that of Ordinary portland cement with ground granulated blast-furnace slag, in case of ground granulated blast-furnace slag 50% mixture. The carbonation of Ecocement and Ordinary portland cement with ground granulated blast-furnace slag was increase, but the increase ratio of carbonation when ground granulated blast-furnace slag was mixed was different in Ecocement and the Ordinary portland cement. Source


Trademark
Taiheiyo Materials Corporation, Sanyo and Taiheiyo Cement Corporation | Date: 2000-08-01

Cement shrinkage reducing agent for use in the manufacture of cement and mortar.


Kakegawa M.,Taiheiyo Materials Corporation | Masuda Y.,Utsunomiya University | Matsubayashi Y.,Taiheiyo Materials Corporation | Kage T.,Japan Building Research Institute
Journal of Structural and Construction Engineering | Year: 2012

This paper reports the results of accelerated test (20°C, 40°C, 60°C and 80°C , moist condition) on the rate of corrosion of reinforcing bar in concrete which contains chloride ion. The factor of experiment are sodium chloride content (0∼1.0%/sand), water-cement ratio (50∼65%), and thickness of concrete cover (10∼30mm). It is concluded as follows, The corrosion loss of reinforcing bar in accelerated test increases in proportion to square root of test period. Rate of corrosion of reinforcing bar in carbonated concrete containing sodium chloride is larger than the rate of corrosion of reinforcing bar in un-carbonated concrete containing sodium chloride. The estimation equation of the rate of corrosion of reinforcing bar in concrete are proposed by sodium chloride content and water- cement ratio. Source


Kakegawa M.,Taiheiyo Materials Corporation | Masuda Y.,Utsunomiya University | Matsubayashi Y.,Taiheiyo Materials Corporation | Kage T.,Japan Building Research Institute
Journal of Structural and Construction Engineering | Year: 2012

This paper reports the results of accelerated test (60°C and 80°C, moist condition) on the rate of corrosion of reinforcing bar in concrete which contains chloride ion. The factor of experiment are sodium chloride content (0∼1.0%/sand), water-cement ratio (50∼65%), and thickness of concrete cover (15∼40mm).It is concluded as follows, The corrosion loss of reinforcing bar in accelerated test increases in proportion to square root of exposure period. Rate of corrosion of reinforcing bar in concrete containing 0 and 0.1% sodium chloride in 80°C is larger than rate of corrosion in 60°C. However rate of corrosion of reinforcing bar in concrete containing 0.3 and 1.0% sodium chloride in 80°C is smaller than rate of corrosion in 60°C. The estimation equation of the rate of corrosion of sodium chloride content(0∼1.0%/sand) are proposed by thickness of concrete cover and water- cement ratio. Source

Discover hidden collaborations