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 83 Abstracts search results

Document: 

SP114-76

Date: 

May 1, 1989

Author(s):

Jan Bijen and Hennie Waltje

Publication:

Symposium Papers

Volume:

114

Abstract:

Cements consisting of 60 percent ground granulated blast furnace slag and 40 percent fly ash activated by 7 percent sodium hydroxide have been investigated. Various slags were used, including some laboratory-made synthetic slags. The influence of additives like superplasticizers and defoaming agents has been examined. The most favorable composition with respect to strength development has been subjected to a durability testing program. A negative aspect appeared to be the carbonation resistance, which is low in comparison with portland cement. Carbonation leads to a decrease in strength. Other properties were favorable.

DOI:

10.14359/1900


Document: 

SP114-35

Date: 

May 1, 1989

Author(s):

Chao-Lung Hwang and Dong-Sheng Wu

Publication:

Symposium Papers

Volume:

114

Abstract:

Rice husk ash (RHA) was obtained under different burning conditions from 400 to 1200 C. The changes in the properties of RHA were investigated by XRD, DAT, and microanalytical techniques. When RHA obtained at different burning conditions was added to cement paste or mortar, several properties such as hydration, setting time, porosity, and strength revealed changes.

DOI:

10.14359/2368


Document: 

SP114-36

Date: 

May 1, 1989

Author(s):

Terence C. Holland

Publication:

Symposium Papers

Volume:

114

Abstract:

The first silica fume admixture aimed at the ready-mixed market appeared in the United States in 1983. Since then, the use of silica fume has developed slowly. Currently, it is being used as a cement replacement material or as a performance-enhancing admixture. This paper reviews the practical aspects of working with silica fume in ready-mixed concrete, with an emphasis on the use of silica fume in the property enhancement role. The forms of silica fume currently being marketed in the United States are briefly described. Then, the current state of specifications for silica fume, admixtures containing silica fume, and concrete incorporating silica fume is examined. Next, aspects of concrete production are discussed. Finally, transporting, placing, finishing, and curing practices are reviewed.

DOI:

10.14359/2376


Document: 

SP114-60

Date: 

May 1, 1989

Author(s):

B. Osrbaeck

Publication:

Symposium Papers

Volume:

114

Abstract:

Two granulated blast furnace slags were ground to different finenesses in a laboratory ball mill and in a vertical roller mill to produce products that differed in fineness level and shape of particle size distributions. The cementitious properties of the products were evaluated by the ASTM C 989 Slag Activity Index Test and the results correlated with the different fineness parameters. The narrower particle size distribution of the roller-mill products resulted in a slight reduction of the packing capacity of the pure slag powder and a slight increase in mortar water requirement with portland cement. The strength-contribution capacity was found to be highly correlated with the specific surface of the slag, irrespective of the way of grinding. Simultaneous drying during grinding did not influence the cementitious properties.

DOI:

10.14359/2600


Document: 

SP114-61

Date: 

May 1, 1989

Author(s):

Della M. Roy

Publication:

Symposium Papers

Volume:

114

Abstract:

Cement pastes and mortars prepared with ASTM Type I cement and 50, 65, 70, and 85 percent granulated blast furnace slag have been investigated. The chloride diffusion rate and permeability of the pastes and mortars show pronounced decreases from the control portland cement pastes and mortars. The decreases are related to the refined microstructures. The pore structure of hardened slag-containing paste is dominated by the pores with radiums finer than 5 nm. But for neat cement paste, the majority of pores range from 5 to 20 nm. This difference in pore size distribution makes the pastes behave quite differently in diffusion and transport processes. The reduction of effective porosity makes the pastes blended with slag much more resistant to chloride diffusion.

DOI:

10.14359/2601


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