Characterization of Nano-Silica Local Metakaolin Based-Geopolymer: Microstructure and Mechanical Properties  

作　　者：Zeineb Zidi Mounir Ltifi Idrees Zafar Zeineb Zidi;Mounir Ltifi;Idrees Zafar(Laboratory of Physics of Materials and Nanomaterials Applied to Environment (LaPhyMNE), Faculty of Sciences of Gabes, Gabes University, Gabes, Tunisia;Department of Civil Engineering, College of Engineering, Al Imam Mohammad Ibn Saud Islamic University, Riyadh, KSA;Department of Civil engineering, National Engineering School of Gabes, Gabes University, Gabes, Tunisia)

机构地区：[1]Laboratory of Physics of Materials and Nanomaterials Applied to Environment (LaPhyMNE), Faculty of Sciences of Gabes, Gabes University, Gabes, Tunisia [2]Department of Civil Engineering, College of Engineering, Al Imam Mohammad Ibn Saud Islamic University, Riyadh, KSA [3]Department of Civil engineering, National Engineering School of Gabes, Gabes University, Gabes, Tunisia

出　　处：《Open Journal of Civil Engineering》2020年第2期143-161,共19页土木工程期刊（英文）

摘　　要：The current study focused on the utilization of local clay for synthesis and characterization of meta-kaolin based geopolymers with and without nano-silica. The control geopolymers, for a compressive strength of 30 MPa, were optimized by using Liquid/Solid ratio of 0.55, NaOH concentration of 10 M and curing at 80<span style="white-space:nowrap;">°</span>C. The nano silica was added in an extended range of 1%, 2%, 3%, 5%, 7% and 10%. The synthesized nano-silica metakaolin based geopolymers w<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">as</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> investigated by using compressive strength, XRD, XRF, FTIR, SEM, MIP, TG, UV/VIS spectroscopy, in addition to density, water absorption and initial setting times. The results indicated an increase in the compressive strength value with the incorporation of nano-silica in geopolymer mixes until the optimum percentage of 5%, while the 10% addition of nano-silica decreased the compressive strength by 5% as compared to the control geopolymer. The increase in the compressive strength was accredited to the increase in the content of N-A-S-H gel and the amorphous structure as shown by XRD and FTIR analysis. In addition, the optical transmittance analysis, MIP and SEM scans along with the results of density and water absorption have clearly shown the densification of the matrix formed for the optimal percentage of nano-silica. However, the initial setting time was found to reduce substantially with increase of nano-silica content. Moreover, the TG results have shown the 5% nano-added geopolymers to have greater thermal stability as compared to reference geopolymer</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:VeThe current study focused on the utilization of local clay for synthesis and characterization of meta-kaolin based geopolymers with and without nano-silica. The control geopolymers, for a compressive strength of 30 MPa, were optimized by using Liquid/Solid ratio of 0.55, NaOH concentration of 10 M and curing at 80<span style="white-space:nowrap;">°</span>C. The nano silica was added in an extended range of 1%, 2%, 3%, 5%, 7% and 10%. The synthesized nano-silica metakaolin based geopolymers w<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">as</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> investigated by using compressive strength, XRD, XRF, FTIR, SEM, MIP, TG, UV/VIS spectroscopy, in addition to density, water absorption and initial setting times. The results indicated an increase in the compressive strength value with the incorporation of nano-silica in geopolymer mixes until the optimum percentage of 5%, while the 10% addition of nano-silica decreased the compressive strength by 5% as compared to the control geopolymer. The increase in the compressive strength was accredited to the increase in the content of N-A-S-H gel and the amorphous structure as shown by XRD and FTIR analysis. In addition, the optical transmittance analysis, MIP and SEM scans along with the results of density and water absorption have clearly shown the densification of the matrix formed for the optimal percentage of nano-silica. However, the initial setting time was found to reduce substantially with increase of nano-silica content. Moreover, the TG results have shown the 5% nano-added geopolymers to have greater thermal stability as compared to reference geopolymer</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Ve

关 键 词：GEOPOLYMER NANO-SIO2 Local-Metakaolin Mechanical Properties Microstructure Properties 

分 类 号：TG1[金属学及工艺—金属学]