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Home > Publications > 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.
Showing 1-5 of 15 Abstracts search results
Document:
SP87-01
Date:
September 1, 1985
Author(s):
Joseph P. Colaco
Publication:
Symposium Papers
Volume:
87
Abstract:
The article describes the use of high-strength concrete in the 75-story composite frame for the Texas Commerce Plaza in Houston. The advantages of the high-strength concrete were to re-duce column sizes and to increase stiffness. All the concrete in this tower (approximately 100,000 cyd.) was successfully pumped, the highest placement being almost a 1,000' above the street level.
DOI:
10.14359/6520
SP87-02
Alex Aswad and Weston T. Hester
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.
10.14359/6521
SP87-03
Kingsley D. Drake
During the past 5 years, the utilization of high-strength concrete in Seattle has come a long way. This paper summarizes high-strength concrete use on 7 projects in the Seattle area, with particular emphasis on 9500 psi (670 kg/sq.cm) concrete at the Columbia Center project. Columbia Center is used as an example of the cooperation and quality control required of the Structural Engineer, Contractor, Concrete Supplier and Testing Laboratory for high-strength concrete. Columbia Center was the first major project to use a high cement content mix in mass (1200 yd3 - approx. 918 m3) placements. Strength gain, modulus of elasticity and temperature rise charac-teristics are presented.
10.14359/6522
SP87-04
R. Lacroix and P. Jaugey
A research program has been promoted in order to study the compositions and properties of High Performance Concretes to be produced in France. Concretes with a characteristic compressive strength of 50 to 60 MPa (7 000 to 8 500 psi) on cylinders tests may be fabricated every where in France at a reasonnable cost, by selecting aggregates, cement and superplasticizers. The Brittle behaviour of such concretes under loads action needs a reevalua-tion and a possible adaptation of the codes of design. The other characteristics of this material are significantly improved : reduction of creep and shrinkage, increase of compacity. The gain to be expected from a generalized use of such concretes results from short time characteristic, by decreasing the member sections and improving the rate of utilization of shuttering, and from long time characteristic by increasing durability. However a complementary program is now in progress in order to clear some uncertain-ties and to design an experimental structure.
10.14359/6523
SP87-05
Pierre-Claude Aitcin, Pierre Laplante, and Claude Bedard
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.
10.14359/6524
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