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 15 Abstracts search results

Document: 

SP87

Date: 

September 1, 1985

Author(s):

Editor: Henry G. Russell

Publication:

Symposium Papers

Volume:

87

Abstract:

SP87 High-strength concretes are used frequently in applications requiring slender members to carry large loads or span long distances. Early applications of high-strength concrete emphasized its use to reduce column dimensions. More recently, high-strength concrete has been used to meet special project objectives such as large composite columns and stiffer structures. In turn, the use of high-strength concrete has prompted the applications of more stringent quality control requirements. This publication highlights the use, design implications, and research results of applications of high-strength concrete.

DOI:

10.14359/14044


Document: 

SP87-13

Date: 

September 1, 1985

Author(s):

Antoine E. Naaman and Joseph R. Homrich

Publication:

Symposium Papers

Volume:

87

Abstract:

The use of high strength concrete is attractive in precast prestressed concrete structures and in earthquake resistant structures for which a reduction in mass is of paramount importance. Yet applications of high strength concrete are hindered by its relative brittleness. Such a drawback can be overcome by addition of fibers. The present study describes the main effects of fiber reinforcement on the compressive stress-strain properties of high strength fiber reinforced mortar and concrete. The influence of various fiber reinforcing parameters such as volume fraction of fibers, aspect ratio, and type of fibers is illustrated. Trade-offs to achieve ductility while maintaining high strength are explained.

DOI:

10.14359/6532


Document: 

SP87-02

Date: 

September 1, 1985

Author(s):

Alex Aswad and Weston T. Hester

Publication:

Symposium Papers

Volume:

87

Abstract:

In the prestressed, precast concrete industry high-strength concretes are widely used for axially loaded piles and columns, but also increasingly for flexural members such as double tee beams and girders. Use of high-strength concretes permits fabrication of longer, more slender spans and economic mild and prestressed reinforcing steel patterns. And, for plant-produced members the necessary high strength may be achieved easily and consistently without out-of-the-ordinary quality control procedures9 and this is documented here. To facilitate designs using high-strength concretes a number of design aids have been developed, and selected examples are persented. Finally, by its very nature, where high early strengths are required prestressed precast concrete members frequently have a substantial amount of long-term reserve capacity and excellent deflection control.

DOI:

10.14359/6521


Document: 

SP87-05

Date: 

September 1, 1985

Author(s):

Pierre-Claude Aitcin, Pierre Laplante, and Claude Bedard

Publication:

Symposium Papers

Volume:

87

Abstract:

Test results of a field experiment are presented where a 90 MPa (13 000 psi) silica fume concrete was used in the construction of an experimental column of a 26-storey highrise building. This concrete used a set-retarding agent in addition to a superplasticizer, had a water/cementitious ratio of 0.25 and was delivered at a slump of 250 mm (10 inches) after 45 minutes of travel. Maximum temperature was reached about 30 hours after mixing and was about 45°C (113°F) higher than the initial temperature of the fresh concrete. The thermal gradient inside the column was never greater than 20"C/m (21"F/ft) and no thermal stress problems were noted. Expressions of the modulus of rupture and modulus of elasticity, as a function of the compressive strength, are proposed. The 91 days shrinkage of this very high strength silica fume concrete was similar to that of plain concrete having a W/C of 0.40. In one concrete batch, due to a superplasticizer overdosage that resulted in an 18-hour set retardation, entrapped air macropores of 1.0 um size were created and caused a 10 MPa (1 450 psi) strength reduction at 91 days.

DOI:

10.14359/6524


Document: 

SP87-14

Date: 

September 1, 1985

Author(s):

Robert C. Chen, Ramon L. Carrasquillo, and David W. Fowler

Publication:

Symposium Papers

Volume:

87

Abstract:

Experimental investigations on the behavior of high strength concrete under uniaxial and biaxial short-term compressive stresses were conducted using thin square plate specimens. Strength, stress-strain relationship, mode of failure, and failure mechanism are discussed. Results confirm that a main cause of the increase in strength, stiffness, and proportional limit of concrete under biaxial compression is the confinement of internal microcracking preventing the development of a progressive failure mechanism. In addition, it was found that as the aggregate stiffness approaches that of the mortar, both the proportional limit and the discontinuity point of the concrete increase due to the reduction of stress concentrations. The observed failure mode for high strength concrete can be explained in terms of the limiting tensile strain criterion.

DOI:

10.14359/6533


123

Results Per Page 




Please enter this 5 digit unlock code on the web page.