کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1457626 989271 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Replacement of the foam index test with surface tension measurements
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی صنعتی و تولید
پیش نمایش صفحه اول مقاله
Replacement of the foam index test with surface tension measurements
چکیده انگلیسی

The foam index test is the method usually employed to determine the degree of fly ash interference with air entrainment agents in concrete. The test involves the use of commercial air-entraining agents (AEAs) and visual observation of foam stability. These facts reduce the reproducibility of the test, because commercially available AEAs vary in strength, and the criteria for foam stability are operator dependent. Therefore, it is of interest to develop a reproducible method, which is able to determine the fly ash quality with respect to air entrainment in concrete. This paper presents efforts toward the development of a new method based on dynamic surface tension measurements, using the bubble pressure method, on filtrate from a fly ash and cement suspension. A pure surfactant is added to the suspension as a substitute for a commercial AEA. The new method and the foam index test have been compared on fly ashes acquired from power plants in Denmark and the U.S. The results reveal a good relationship between the two methods, but the new method requires further work before a finished procedure is accomplished. Finally, it has been shown that changes in temperature affect both test methods.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Cement and Concrete Research - Volume 37, Issue 6, June 2007, Pages 996–1004
نویسندگان
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