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 91 Abstracts search results

Document: 

SP128-73

Date: 

November 1, 1991

Author(s):

C. Goodspeed, M. Zhang, J. Yost, and E. Schmeckpeper

Publication:

Symposium Papers

Volume:

128

Abstract:

The components of force transfer developed by fiber reinforced plastic (FRP) grids are investigated under uniaxial tension and compression loads and under a bending load. Three contributing mechanisms of force transfer in FRP grids are studied: chemical adhesion between the concrete and resin, bonding along the two rough sides of the longitudinal member, and bearing against one side of the transverse members. Development length necessary for force transfer is investigated in three splice details.

DOI:

10.14359/2354


Document: 

SP128-44

Date: 

November 1, 1991

Author(s):

T. Kato, H. Umehare, and H. Yoshida

Publication:

Symposium Papers

Volume:

128

Abstract:

In repairing cracked concrete structures, excellent workability and repairing effects have been obtained by using epoxy resins that are liquid organic polymer materials. However, in most situations, the repairing effects are not long-term and when these organic materials are used and exposed outside for a few years, they will deteriorate. Therefore, a material for crack injection, utilizing inorganic material such as ultra-fine slag cement, has been developed recently, and has shown good performance in terms of workability and durability. In this study, plain concrete beams and reinforced concrete beams repaired by using epoxy resin or ultra-fine slag cement are tested. The results show that the repairing effect deteriorates because of bleeding or drying shrinkage when inorganic material is used with a great deal of water. However, satisfactory properties are obtained using superplasticizer added to the inorganic repair material.

DOI:

10.14359/2078


Document: 

SP128-45

Date: 

November 1, 1991

Author(s):

T. Ilsaka., A sugiyama, and H. Umehara

Publication:

Symposium Papers

Volume:

128

Abstract:

In the present study, materials for repairing cracks that occur in concrete structures are discussed. Up to now, organic materials have been used mainly to repair cracks in concrete, but these have problems of heat resistance and durability, etc. Therefore, to overcome these problems, blast furnace cement, which is an inorganic material from the same group as the constituent element of concrete, is chosen and used as an impregnating material by pulverizing it to an ultra-fine powder. The specific gravity of this material is 2.96, the average particle diameter is 2.9 micrometers, and the specific area equals 9500 cmý/g, which is almost three times that of normal cement. It is found that the viscosity of the blast furnace cement paste with a water-cement ratio equal to 70 percent is less than 35 MPa/s, which is almost the same viscosity as epoxy resin. Consequently, the paste of ultra-fine powder will be able to penetrate cracks like epoxy resin and is expected to be a suitable repair material.

DOI:

10.14359/2090


Document: 

SP128-17

Date: 

November 1, 1991

Author(s):

Akira Ohata and Giles Goldsbro

Publication:

Symposium Papers

Volume:

128

Abstract:

The paper briefly introduces experience with rotating machinery grouting, and the perceived need for a high-temperature service polymer-based grout material. It discusses design and handling parameters, and the development of a product that cures at ambient temperatures, without appreciable shrinkage, and has a compressive strength at 150 C of more than 40 MPa.

DOI:

10.14359/1917


Document: 

SP128-18

Date: 

November 1, 1991

Author(s):

L. R. Prudencio, Jr.

Publication:

Symposium Papers

Volume:

128

Abstract:

The evaluation of early-age strength of shotcrete is very important for some kinds of applications, for example, tunnel linings. However, until now there has been no suitable procedure for this purpose. This paper provides information on a test program carried out to establish an experimental procedure to evaluate the compressive strength of shotcrete at early age (to 8 MPa). Results obtained using the Meynadier needle and the constant energy penetrometer are shown. The first test was employed for very low-strength concrete (less than MPa) and the second covered a higher range (1 to 10 MPa). The influence of mixture proportions on the test results was evaluated.

DOI:

10.14359/1932


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