International Concrete Abstracts Portal

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 90 Abstracts search results

Document: 

SP132

Date: 

May 1, 1992

Author(s):

Editor: V.M. Malhotra

Publication:

Symposium Papers

Volume:

132

Abstract:

SP-132 Published in two volumes...The first volume contains papers dealing with fly ash and natural pozzolans. The second volume consists of papers dealing with condensed silica fume and ferrous and non-ferrous slags.

DOI:

10.14359/14164


Document: 

SP132-53

Date: 

May 1, 1992

Author(s):

Malvin Sandvik and Odd E. Gjorv

Publication:

Symposium Papers

Volume:

132

Abstract:

Silica fume has an accelerating effect on the early hydration of portland cement. Also, silica fume reduces the retarding effect of lignosulfates. At standard curing conditions, the contribution to strength from the pozzolanic reaction takes place primarily at 5 to 7 days. As a result, existing equations for prediction of strength development based on pure portland cement are no longer valid for concrete with silica fume. Some new equations for concrete with various contents of silica fume are presented.

DOI:

10.14359/2365


Document: 

SP132-54

Date: 

May 1, 1992

Author(s):

M. Kakizaki, H. Edahiro, T. Tochigi, and T. Niki

Publication:

Symposium Papers

Volume:

132

Abstract:

High-strength and ultra high-strength cast-in-place concretes tend to contain excessive unit volumes of cement when compared with normal concrete, and since the improvement of workability relies largely on the efficiency of the air-entraining and high-range water-reducing admixtures, the properties of workability (or consistency) are different from normal concrete. With high-strength concrete, it was found that the method of mixing concrete influenced flowability, strength properties, and pore structure; details of this influence are given.

DOI:

10.14359/2375


Document: 

SP132-55

Date: 

May 1, 1992

Author(s):

G. G. Carette and V. M. Malhotra

Publication:

Symposium Papers

Volume:

132

Abstract:

Presents results of an investigation dealing with the long-term strength of silica fume concrete. Three series of concrete mixtures with and without silica fume were made with water-cementitious ratios from 0.25 to 0.40. The replacement level of portland cement with silica fume was kept constant at 10 percent. Test specimens were cast from each mixture to determine the compressive and flexural strengths of concrete at up to 3.5 years under both water-curing and air-drying conditions. The test specimens were also subjected to the determination of microstructure, carbonation, and weight changes with time. It is concluded that, under water-curing conditions, both the control and silica-fume concretes show gain in strength with age, with both concretes reaching similar strength levels after 3.5 years. However, continuous air-curing adversely affects the long-term compressive strength development of both types of concrete. This effect is considerably more marked for silica-fume concrete than for the control concrete, especially at w/c + sf of 0.30 and 0.40.

DOI:

10.14359/2383


Document: 

SP132-51

Date: 

May 1, 1992

Author(s):

V. G. Batrakov, S. S. Kaprielov, and A. V. Sheinfeld

Publication:

Symposium Papers

Volume:

132

Abstract:

Results of an investigation of cement paste structure, and strength, permeability, and frost resistance of concrete with admixtures of silica fume type are given. The admixtures are waste materials from metallic silicon, low-grade ferrosilicon, ferrosilicon chrome production, containing SiO2 in the amount of 92, 70, and 66 percent, and surface area of 25.0, 44.9, and 18.5 mý/g, respectively. The influence of the admixtures on the cement paste microstructure results in an increase of gel porosity volume, decrease of capillarity porosity, and in an increase of strength. Thus, concrete strength increases and its permeability decreases. Physical and chemical properties of the silica fume-type admixtures insignificantly affect gel pore volume, whereas they have significant influence on capillary porosity. An increased dosage of high-range water-reducing admixture (HRWR) is a beneficent factor in increasing hydration degree and gel porosity, decreasing capillary porosity volume, and, consequently, increasing strength. Concrete frost resistance with silica fume dosages up to 10 percent of cement mass is not lower than the reference concrete with the same amount of binder.

DOI:

10.14359/2348


12345...>>

Results Per Page 




Edit Module Settings to define Page Content Reviewer