The Effect of Alkali on Compressive of Metakaolin Based Geopolymeric Cement

Abstract

In this study, Metakaolin was used as source material, NaOH and sodium silicate were used as alkali activators.Preparation of three sets of geopolymer samples subject different NaOH concentration from 8 to16mol/L. The effect of alkaline concentration on compressive strength was analyzed. NaOH concentrations at 12mol/L and 16mol/L resulted in high 7-day compressive strengths. And the compressive strength of geopolymeric cement reached the maximum when adding 24mL sodium silicate at SiO2:Na2O ratio 3.3.

Influence of Synthesis Factors on Properties of Geopolymers Based on Red Mud and Rice Husk Ash

“…Therefore, the proper Na 2 O/Al 2 O 3 molar ratio was 2.0. This survey proved an important role of NaOH in geopolymerization between RM and RHA and the mechanism of this process was predicted as follows [1,4]:…”

“…Geopolymer which is amorphous appears to be a potential alternative to the classic hydraulic binders. The exothermic reaction of geopolymerization generates a structure similar to zeolites [1] that is mainly produced from the reaction between metakaolin (source of Si and Al) and hydroxides or alkaline silicate solutions [2,3,4]. According to D. Kim et al [5], geopolymers can be classified into two major groups: (i) pure inorganic geopolymers and (ii) organic containing geopolymers.…”

“…According to D. Kim et al [5], geopolymers can be classified into two major groups: (i) pure inorganic geopolymers and (ii) organic containing geopolymers. The geopolymerization mechanism involves Si and Al dissolution from the starting materials and forms available polysialate units 4 ] tetrahedral units, with charge balance ensured by Na + or K + ions [3]. Moreover, geopolymers have the advantage to be possibly formulated from a wide range of aluminosilicate minerals (e.g.…”

Influence of sodium-based activators and water content on the fresh and hardened properties of metakaolin geopolymers

“…In comparison, a lower number of studies have been dedicated to low-calcium precursors such as metakaolin or other calcined clays as they tend to require higher water demand and exhibit lower workability [25]. Nevertheless, there is a growing interest on optimizing the properties of calcined clay/metakaolin-based geopolymers due to raw materials availability [25,26], and literature reports 28-day strengths between 20 to 80 MPa with molar oxide ratios in the ranges of SiO 2 /Al 2 O 3 of 2.5-4, Na 2 O/Al 2 O 3 of 0.6-1.2, and H 2 O/Al 2 O 3 of 10-11 [27][28][29][30][31][32][33]. In addition, besides similar work conducted by Albidah [34] and Alghannam [35] in metakaolin based concrete, to the authors' best knowledge there is still a lack of studies comparing the rheology of the fresh metakaolin geopolymer pastes with their hardening evolution properties, microstructure and resulting mechanical strength.…”

Alkali-Activated Binders Produced From Petrochemical Fluid Catalytic Cracking Catalyst Waste

“…Several different precursor materials have been activated such as metakaolin [7,8,9,10,11], fly ashes [12,13,14,15], blast-furnace slag [9,11,16], natural zeolites [6], tungsten mine waste [17], red clay brick wastes [18] and waste from oil-industry [19,20,21].…”