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 62 Abstracts search results

Document: 

SP179-39

Date: 

June 1, 1998

Author(s):

A. Yasumoto, Y. Edamatsu, M. Mizukoshi and S. Nagaoka

Publication:

Symposium Papers

Volume:

179

Abstract:

in conjunction with Self-Compacting Concrete and the varying resistance levels to shrinkage crack due to autogenous and drying shrinkage. Resistance was estimated by comparing the cracking-ages of the concrete under restrained conditions. The powdered materials used were normal portland cement, low-heat portland cement, portland blast-furnace slag cement, two blends of normal portland cement and limestone powder (the blending volume ratios of limestone powder were 30% and 55%). From the results of the experiments, it became clear that the resistance level of Self-Compacting Concrete to shrinkage crack was quite different depending on the type of powdered materials used.

DOI:

10.14359/6066


Document: 

SP179-40

Date: 

June 1, 1998

Author(s):

S. Hiraishi, K. Yokoyama and Y. Kasai

Publication:

Symposium Papers

Volume:

179

Abstract:

Flowing concrete is a highly flowable and segregation resistant concrete. Shrinkage of the concrete at early ages up to 24 hours under a constant air flow of 8 m/s starting at the age of 2 hours, and crack propagation of the concrete in a restricted form with a thickness of 50 mm have been studied. The experiments were done by controlling the following four mixture parameters, (I) Water - cement ratio: 0.60, 0.45, 0.35, 0.30 and 0.27, (2) Unit amount of water: 185, 175 and 170 kg/m3, (3) Type of cement: normal, high early strength and belite portland cement, (4) Type of inorganic admixture: a ground granulated blast furnace slag and a fly ash and their respective mixture proportions. Effects of the above parameters on crack propagation at early ages were investigated on the basis of authors’ crack evaluation criteria.

DOI:

10.14359/6067


Document: 

SP179-41

Date: 

June 1, 1998

Author(s):

H. Chu and A. Machida

Publication:

Symposium Papers

Volume:

179

Abstract:

Two aspects of researches concerning the self compacting concrete techniques have been extensively carrying out in Japan. One aspect is to find a systematic way to evaluate the consistency experimentally. The other is to seek a theoretical way to predict the properties. Thus for the first goal, in this paper three kinds of methods including the dragging ball viscometer test, the slump flow test and the 075 funnel test were proposed to investigate the influence of concrete mixture proportions on the consistency of viscous agent series self compacting concrete. For the second goal, a numerical approach was initially proposed to simulate the behavior of self compacting concrete called Modified Distinct Element Method (MDEM). The applicability of MDEM is verified by comparing the simulation results with the experimental results of the above three types of tests.

DOI:

10.14359/6068


Document: 

SP179-42

Date: 

June 1, 1998

Author(s):

N. Kawaguchi, K. Kohno, Y. Kurose and T. Bakoshi

Publication:

Symposium Papers

Volume:

179

Abstract:

The durability and strength characteristics of high-volume fly ash concrete were studied in order to utilize fly ash, an industrial by-product from coal fired thermal power plants, as a typical admixture for concrete. The results of this study were as follows: (1) The strength development of high-volume fly ash concrete is higher than that of conventional concrete. (2) There is an optimum mixing ratio of fly ash, in which the compressive strength reaches a maximum level. (3) Freezing and thawing resistance of high-volume fly ash concrete is almost the same as that of conventional concrete. (4) Abrasion resistance, durability in marine environment, and water-tightness are improved by the use of high-volume fly ash. (5) Adiabatic temperature rise can be reduced compared with that of concrete without fly ash.

DOI:

10.14359/6069


Document: 

SP179-43

Date: 

June 1, 1998

Author(s):

A. Kawamura, M. Kuromoto and T. lwai

Publication:

Symposium Papers

Volume:

179

Abstract:

This paper discusses the mechanism of the setting shrinkage of polymer concrete with liquid resin mainly composed of methyl methacrylate (MMA-PC) and reports the study results on the method for reducing the setting shrinkage. The setting shrinkage is classified into two large categories, that is, shrinkage due to polymerization and shrinkage caused by temperature decrease after the maximum temperature is reached. The shrinkage amount due to temperature decrease is in proportion to the liquid resin content. The authors demonstrated that the shrinkage due to polymerization significantly vanes with the formation state of matrix of liquid resin with tiller. For reducing the shrinkage, it is effective to confine the shrinking strain by adding fibers and modifying the filler properties to limit the volume change due to polymerization.

DOI:

10.14359/6070


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