Statistical Model for Predicting the Optimum Gypsum Content in Concrete
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Abstract
The problem of internal sulfate attack in concrete is widespread in Iraq and neighboring countries.This is because of the high sulfate content usually present in sand and gravel used in it. In the present study the total effective sulfate in concrete was used to calculate the optimum SO3 content. Regression models were developed based on linear regression analysis to predict the optimum SO3 content usually referred as (O.G.C) in concrete. The data is separated to 155 for the development of the models and 37 for checking the models. Eight models were built for 28-days age. Then a late age (greater than 28-days) model was developed based on the predicted optimum SO3 content of 28-days and late age. Eight developed models were built for all ages. The important results obtained from the developed models are the positive effect of C3S, C3A
and C4AF on optimum SO3 content. The effect of C3A on optimum SO3 content is about twice that of C4AF. The study also showed a trend of positive and important effect of the fineness of cement except
in some models and this is due to statistical overlap
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References
Abdul-Latif, A.M. (1997)
أطروحة ," توافق محتوى الكبريتات في مكونات الخرسانة"ماجستير، كلية الهندسة ،جامعة بغداد، ص 34-39 ، 57.
Abdul-Latif, A.M. (2001), “Optimum gypsum content in cement mortar and concrete“, Ph.D. Thesis, College of Engineering, University of Baghdad. Abood , S.H. (1989) , “ Creep of concrete with ulfate contaminated aggregate “ Ms.C. Thesis , College of Engineering , University of Baghdad , pp.110-112,81,100.
Ali, N.H. (1981), “Effect of sulfates content on concrete with different gypsum content cements“, Ms.C Thesis, College of Engineering, University of Baghdad, pp.145-149,128,137.
Al-Qissi, A.W. (1989),
" فاعلية الكبريتات الملوثة للرآام الناعم في الخرسانة" ، رسالة ماجستير ، آلية الهندسة ، جامعة بغداد .
Al-Rawi, R.S. (1977), “Gypsum content of cement used in concrete cured by accelerated method “, ASTM Journal of Testing and Evaluation, Vol.5, No. 3, pp.231-237.
Al-Rawi, R.S. , Al-Salihi ,R.A. and Ali , N.H. (2002)-A “ Effective sulfate content in concrete ingredient “ , Challenges of concrete construction Symposium , University of Dundee , Scotland , U.K.
Al-Salihi , R.A. (1994) , “Proposed revision of Iraqi specifications for concrete ingredients to cope with post war era “ , Ms.C thesis , College of Engineering , University of Baghdad , pp.20,37,60-63,97-102.
Drapper, N. R. and Smith, H. (1981), “Applied regression analysis “, John Wiley, New York, pp. 709.
Montgomery, D.C. and Peack, E.A., (1992)," Introduction to linear regression analysis ", 2nd Edition, John Wiley and Sons, Inc., New York.
SPSS manual, (1992), Statistical package for social science, version 10, electronic help file.
Yousif , S.H. (1980) , “ Effect of sulfate on lean and medium richness concrete “ , Ms.C Thesis , College of Engineering , University of Baghdad, pp.93,98-101 .
Zari, A.S. (1981), “Role of aggregate in sulfate effect on cement mixes“, Ms.C Thesis, College of Engineering, University of Baghdad, pp.151- 155,137.