ABOUT THE INTERNATIONAL CONCRETE ABSTRACTS PORTAL

  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal

Showing 1-5 of 41 Abstracts search results

Document: 

SP93-33

Date: 

September 1, 1986

Author(s):

S. L. Marshall and R. E. Pelkey

Publication:

Symposium Papers

Volume:

93

Abstract:

Precast concrete ‘I’ girder sections are commonly used in Bridge construction in the Province of British Columbia. The Annacis Channel East bridge represents the latest development in the trend to longer and deeper ‘I’ girders. Prior to this project, there were six standard ‘I’ girder shapes ranging in depth from 914mm (3.0 ft.) to 2300mm (7.6 ft.). A new section 2750mm (9.0 ft.) deep, was specially developed to allow span lengths of 60m (196.9 ft.) and 71m (233.0 ft.) and thereby reduce the number of river piers from three to two. A $1.0 million premium cost for the super-structure was more than offset by the $2.5 million savings for one river pier. A further development involved the field splicing of a segment balanced on a pier cap and side span segment with a cast-in-place diaphragm and field post-tensioning.

DOI:

10.14359/6326


Document: 

SP93-40

Date: 

September 1, 1986

Author(s):

Y. Guohua

Publication:

Symposium Papers

Volume:

93

Abstract:

In recent years, approximately 50 large port and harbour reinforced concrete structures have been investigated in China. Analysis of temperature stress and cracking of Concrete has been made on the basis of the results of observa-tion and field testing using remote transducers embedded in the six large dry docks. Concrete temperature and stress have been calculated by several methods. Results of our study indicate that temperature cracking may be caused by high temperature stress even when careful attention is paid to concrete quality, design and construction loads, if adequate measures for reducing temperature stress have not been taken. Temperature stress appears to be mainly related to temperature change, temperature difference and restrained conditions. According to the local conditions in China, measures to prevent temperature cracking are recommended as: carefully analyzing and calculating temperature differences and concrete stress during initial stages of construction, decreasing cement contents, selecting good types of cement and aggregate, appropriate grading and proportioning of concrete, reducing concrete placing temperature, peak temperature, temperature differences and degree of restraint, appropriately selecting the dimensions of concrete blocks, subdivisions and lifts, using steel forms, limiting delay time between concrete placement, good curing and winter proofing the concrete. If measures as above are taken good results can be obtained. This research has been verified in practice in port and harbour engineering in China.

DOI:

10.14359/6333


Document: 

SP93-23

Date: 

September 1, 1986

Author(s):

A. J. Kirkness and J. S. Guarre

Publication:

Symposium Papers

Volume:

93

Abstract:

The Vancouver (B.C.) Advanced Light Rapid Transit System (ALRT) has been selected as an example of a comprehensive transportation construction project where Quality Assurance played a major role. The primary aspects of a Q.A. philosophy, and its interrelationships with other design and construction requirements, are summarized. Discussion of the methodology of Q.A. for the ALRT links these conceptual ideas to the actual design and construction of the guideway system. The precast concrete beam manufacturing process, and the interfacing of Quality Control and Quality Assurance functions during beam manufacture, provide examples of a systematic approach to review, monitoring and recording all significant factors. The paper concludes with reference to the need for appropriate allocation of responsibility to attain desired results, and the delegation of the necessary authority to achieve those results.

DOI:

10.14359/6316


Document: 

SP93-28

Date: 

September 1, 1986

Author(s):

N. P. Bada

Publication:

Symposium Papers

Volume:

93

Abstract:

Several of the bridge non air-entrained concrete bearing seats on the International Control Dam have concrete deterioration from the application of de-icing salts. A 410 tonne beam and deck slab assembly was raised by twelve hydraulic lift climbing jacks assembled to a single span Bailey Bridge Structure. The concrete repair consisted of removing the deteriorated concrete, application of an epoxy bonder, wood forming, and placing of good quality concrete. The 410 tonne beam and deck slab was lowered onto new elastomeric bearing pads to its original location. The paper details the construction procedures and methods of repair to concrete in Spans 2 and 4.

DOI:

10.14359/6321


Document: 

SP93-15

Date: 

September 1, 1986

Author(s):

T. I. Campbell and M. S. Mirza

Publication:

Symposium Papers

Volume:

93

Abstract:

A research and development program on prestressed concrete ties for use on open deck railway bridge systems is described. This program involved the design and fabrication of prototype ties, studies of load distribution of a static wheel load among the ties, both by mathematical modelling and laboratory tests on a full-scale bridge system, determination of the strength of individual ties under static and repeated loadings, field testing of bridge systems in service, and a laboratory study of dynamic load distribution in the bridge system. It is shown that three parameters have a significant influence on the distribution of static wheel loads among the ties and that a linear relationship exists between the load taken by a tie and the tie spacing. Laboratory testing for static load distribution showed good correlation with an analyical model, while tests on individual ties indicated adequate strength under static and repeated loadings. Field tests, which are being conducted to determine the loading on individual ties and the behaviour of the ties under railroad traffic, are described and preliminary data are presented.

DOI:

10.14359/6308


12345...>>

Results Per Page