%0 Journal Article %1 El_Hafid_2017 %A El Hafid, Kenza %A Hajjaji, Mohamed %A El Hafid, Hassan %D 2017 %I Elsevier BV %J Journal of Building Engineering %K (DSC) Calcined Calorimetry Clay DRX Deconvolution Differential FTIR Geopolymers Mechanical Microstructure Physical Properties Scanning properties %P 158--165 %R 10.1016/j.jobe.2017.04.012 %T Influence of NaOH concentration on microstructure and properties of cured alkali-activated calcined clay %U https://doi.org/10.1016%2Fj.jobe.2017.04.012 %V 11 %X Microstructure of cured mixes composed of kaolinitic-illitic raw clay calcined at 700 °C and sodium hydroxide (4–14 M) was investigated using X-ray diffraction, Fourier-transform infrared spectroscopy, Scanning electron microscopy and Thermal analysis. The change of the properties (flexural strength, density, water absorption, open porosity and electrical conductivity) versus NaOH concentration was evaluated and the possible formation of zeolite ZK-14 within the geopolymer matrix from the amorphous clay phases (mainly metakaolinite) was examined. Sodium carbonate was detected as a carbonation product. Due to heating, geopolymers were characterized by dehydration and subsequent recrystallization into nepheline. The development of the fibrous-zeolitic phase was favored by the increase of NaOH concentration and its impact on the studied properties was somewhat advantageous. The rise of alkali concentration within 4–11.5 M enhanced the extent of geopolymerization. The water absorption kinetic obeyed a pseudo-first order equation and the constant was in the range (18.38–51.01) x 10⁻² min⁻¹.

@article{El_Hafid_2017, abstract = {Microstructure of cured mixes composed of kaolinitic-illitic raw clay calcined at 700 °C and sodium hydroxide (4–14 M) was investigated using X-ray diffraction, Fourier-transform infrared spectroscopy, Scanning electron microscopy and Thermal analysis. The change of the properties (flexural strength, density, water absorption, open porosity and electrical conductivity) versus NaOH concentration was evaluated and the possible formation of zeolite ZK-14 within the geopolymer matrix from the amorphous clay phases (mainly metakaolinite) was examined. Sodium carbonate was detected as a carbonation product. Due to heating, geopolymers were characterized by dehydration and subsequent recrystallization into nepheline. The development of the fibrous-zeolitic phase was favored by the increase of NaOH concentration and its impact on the studied properties was somewhat advantageous. The rise of alkali concentration within 4–11.5 M enhanced the extent of geopolymerization. The water absorption kinetic obeyed a pseudo-first order equation and the constant was in the range (18.38–51.01) x 10⁻² min⁻¹.}, added-at = {2019-10-14T00:38:16.000+0200}, author = {El Hafid, Kenza and Hajjaji, Mohamed and El Hafid, Hassan}, biburl = {https://www.bibsonomy.org/bibtex/26d77e49f53b1bb10d48a7b08f075ea14/kutuqueen}, description = {The paper focussed on the effect of NaOH concentration as the sole alkali-activator (excluding the use of waterglass activator) on the microstructure transformations and the properties (flexural strength, density, water absorption, open porosity & electrical conductivity) of heated clay - based geopolymer. The FT-IR deconvolution of the broad band near 1000 cm-1 (asym stretching of Si-O-T) was particularly discussed in relation to the geopolymerization behavior. The electrical conductivity was also further discussed (see the Supplementary data at the online version at http://dx.doi.org/10.1016/j.jobe.2017.04.012). Please, If you are interested in the content of this paper, send me a request via Academia, Researchgate or my e-mail adress { elhafid.kenza@gmail.com } !!! ~ Thank you very much for your interest ~}, doi = {10.1016/j.jobe.2017.04.012}, interhash = {aa7c3693ebc361c9e7a76859ef7386a5}, intrahash = {6d77e49f53b1bb10d48a7b08f075ea14}, journal = {Journal of Building Engineering}, keywords = {(DSC) Calcined Calorimetry Clay DRX Deconvolution Differential FTIR Geopolymers Mechanical Microstructure Physical Properties Scanning properties}, month = may, pages = {158--165}, publisher = {Elsevier {BV}}, timestamp = {2019-10-16T00:45:08.000+0200}, title = {Influence of {NaOH} concentration on microstructure and properties of cured alkali-activated calcined clay}, url = {https://doi.org/10.1016%2Fj.jobe.2017.04.012}, volume = 11, year = 2017 }