کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
259574 503638 2012 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Kaolinitic calcined clays: Factors affecting its performance as pozzolans
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی عمران و سازه
پیش نمایش صفحه اول مقاله
Kaolinitic calcined clays: Factors affecting its performance as pozzolans
چکیده انگلیسی

Five natural kaolinitic clays from different regions of Argentine, with different kaolinite content, different impurities and different degree of crystallinity were calcined in a fixed-bed electrical furnace at 700 °C. Clays were characterized by X-ray diffraction (XRD) and Fourier transformed infra-red spectrometry (FTIR) that provides an index about the order/disorder of the structure. After heat treatment, the structural changes were characterized by XRD and FTIR, and pore size distribution and specific surface were determined. Their pozzolanic activity was evaluated with the Frattini test, electrical conductivity in saturated Ca(OH)2 solution and compressive strength on mortars at 7, 28 and 90 days. Among tested clays, four of them can be classified as pozzolan by the Frattini test. The pozzolanic activity of the natural clays showed good correlation with the content of kaolinite, the inversed of structure order determined by FTIR, and the specific surface of calcined clays. This study confirms that natural clays other than pure kaolinite can be interesting pozzolanic materials when thermally activated.


► Five local kaolinitic clays have been characterized.
► Their pozzolanic activity after calcination at 700 °C was investigated.
► Compressive strength (CS) of PC with 30% of pozzolana reaches or surpasses CS of PC mortar.
► The CS depends the specific surface of calcined clay, kaolinite content and structural disorder.
► All these parameters are condensed in an equation that model de overall system.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Construction and Building Materials - Volume 28, Issue 1, March 2012, Pages 276–281
نویسندگان
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