کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7885398 | 1509748 | 2015 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Acid attack on hydrated cement - Effect of mineral acids on the degradation process
ترجمه فارسی عنوان
حمله اسید به سیمان هیدراته - تاثیر اسید معدنی بر روند تخریب
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موضوعات مرتبط
مهندسی و علوم پایه
سایر رشته های مهندسی
مهندسی صنعتی و تولید
چکیده انگلیسی
During acid attack on concrete structural components, a degraded layer develops whose properties as a protective barrier are decisive for durability. 29Si NMR spectroscopy and 27Al NMR spectroscopy were used with XRD to investigate the degraded layer on hardened cement paste exposed to HCl and H2SO4. The layer comprises an amorphous silica gel with framework silicates, geminate and single silanol groups in which Si is substituted by Al. Amorphous Al(OH)3 and Fe(OH)3 are present. The gel forms by polycondensation and cross-linking of C-A-S-H chains at AlO4 bridging tetrahedra. In the transition zone between the degraded layer and the undamaged material, portlandite dissolves and Ca is removed from the C-A-S-H phases maintaining their polymer structure at first. With HCl, monosulphate in the transition zone is converted into Friedel's salt and ettringite. With H2SO4, gypsum precipitates near the degradation front reducing the thickness of the transition zone and the rate of degradation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Cement and Concrete Research - Volume 74, August 2015, Pages 35-43
Journal: Cement and Concrete Research - Volume 74, August 2015, Pages 35-43
نویسندگان
T. Gutberlet, H. Hilbig, R.E. Beddoe,