Concrete Journal

Application of Water Jet Technology to the Civil Engineering Field

I. Adachi

2001 Volume 39 Issue 6 Pages 3-7
Published: June 01, 2001
Released on J-STAGE: April 26, 2013

DOIhttps://doi.org/10.3151/coj1975.39.6_3

JOURNAL FREE ACCESS

Show abstractHide abstract

The work by the water jet technology carries out cutting, breaking or surface treatment using the water jet system in respect of the object. The water is made to jet from the nozzle of 0.1 to 2 mm by the processing in about pressure of from 50 to 500 MPa out and is carried out. The speed of the jet of the water may be rapider than the sound velocity. The example of which it was applied in civil engineering field by recently confirming the merit of this technology increased again. Here, it is stated generally that the water jet technology is useful for advance and development of civil engineering technology.

View full abstract

Download PDF (1404K)
Present Aspects on Inspection and Diagnosis of Concrete Structures

E. Matsumura

2001 Volume 39 Issue 6 Pages 8-15
Published: June 01, 2001
Released on J-STAGE: April 26, 2013

DOIhttps://doi.org/10.3151/coj1975.39.6_8

JOURNAL FREE ACCESS

Show abstractHide abstract

A lot of the civil structures built during the highly developed periods of the 1970s, will become 50 years old in the 2020s and some will be more aging. For this reason, extension of the life of existing civil structures is being strongly emphasized. Moreover, as seen from the recent accidents of the falling-down of concrete fragments, it is attentive by the society to the damages that are highly possible to cause injury to a third person, although may not affect the capacities of the structures directly. The technologies to upgrade the durability of concrete structures are therefore greatly concerned. From aforesaid causes, it is necessary to take suitable inspection to existing concrete structures to detect early the damages which may possibly affect the capacities of the structures or cause injury to a third person and take appropriate measures if needed basing on detailed investigation to extend the life span or durability. This paper is to introduce from the views of practice the methods of inspection/investigation to civil concrete structures and the present aspects of the diagnosis technologies and the application of non-destructive testing.

View full abstract

Download PDF (9553K)
Technical Trend for Rational Construction of Concrete Structures

Y. Ito, K. Ozawa, S. Ushijima, T. Watanabe

2001 Volume 39 Issue 6 Pages 16-21
Published: June 01, 2001
Released on J-STAGE: April 26, 2013

DOIhttps://doi.org/10.3151/coj1975.39.6_16

JOURNAL FREE ACCESS

Show abstractHide abstract

The Millennium Project's “Research Into a Next-Generation Construction System Using High-Quality Concrete” has been underway since 2000. As part of their research, the authors are investigating the rational construction techniques of concrete structures, and have arrived at a classification of the four elemental techniques of a) lifting and erection, b) formwork, c) reinforcing steel bar work, and d) concreting. This report introduces each elemental technique. The development of each elemental technique has relied on advances in mechanization and automation, and this trend is predicted to continue through additional advances in information technology (“IT”). Moreover, a change in design focus (from conservation of materials to conservation of working time) is currently advancing in the field of structural design, as new shapes and re-bar arrangements pave the way for rational construction.

View full abstract

Download PDF (1080K)
The State of the Art Report of Repair Work Strategy for Large Port Facilities

Manual for investigation and repair of deteriorated jetties in Ohi container terminal

Y. Okudaira, H. Seki, H. Kawada, Y. Fujimatu

2001 Volume 39 Issue 6 Pages 22-27
Published: June 01, 2001
Released on J-STAGE: April 26, 2013

DOIhttps://doi.org/10.3151/coj1975.39.6_22

JOURNAL FREE ACCESS

Show abstractHide abstract

Deterioration of reinforced concrete structures exposed to marine environment has caused serious problem when utilized the facilities. Presently in Ohi container terminal, redevelopment project is carried out with the aim at completion of an international container terminal for the 21st century. As a part of this project, open type jetties supported by piles constructed in 1970's are repaired on a large scale against deterioration in saline environment, conforming to “Manual (draft) for investigation and repair of deteriorated jetties in Ohi container terminal” (published in 1994. 3). In this report, the revised Manual (published in 2000. 3) is introduced, which is added the knowledge got through the repair work.

View full abstract

Download PDF (1123K)
[title in Japanese]

[in Japanese]

2001 Volume 39 Issue 6 Pages 29-32
Published: June 01, 2001
Released on J-STAGE: April 26, 2013

DOIhttps://doi.org/10.3151/coj1975.39.6_29

JOURNAL FREE ACCESS

Download PDF (17121K)
[title in Japanese]

[in Japanese], [in Japanese], [in Japanese], [in Japanese]

2001 Volume 39 Issue 6 Pages 33-38
Published: June 01, 2001
Released on J-STAGE: April 26, 2013

DOIhttps://doi.org/10.3151/coj1975.39.6_33

JOURNAL FREE ACCESS

Download PDF (10998K)
[title in Japanese]

[in Japanese], [in Japanese], [in Japanese], [in Japanese]

2001 Volume 39 Issue 6 Pages 39-43
Published: June 01, 2001
Released on J-STAGE: April 26, 2013

DOIhttps://doi.org/10.3151/coj1975.39.6_39

JOURNAL FREE ACCESS

Download PDF (15134K)
[title in Japanese]

[in Japanese], [in Japanese]

2001 Volume 39 Issue 6 Pages 55-57
Published: June 01, 2001
Released on J-STAGE: April 26, 2013

DOIhttps://doi.org/10.3151/coj1975.39.6_55

JOURNAL FREE ACCESS

Download PDF (726K)
[title in Japanese]

[in Japanese], [in Japanese]

2001 Volume 39 Issue 6 Pages 62-65
Published: June 01, 2001
Released on J-STAGE: April 26, 2013

DOIhttps://doi.org/10.3151/coj1975.39.6_62

JOURNAL FREE ACCESS

Download PDF (19628K)

Register with J-STAGE for free!