Preparation and characterization of acid-based geopolymer using metakaolin and disused polishing liquid

Silico-Aluminophosphate and Alkali-Aluminosilicate Geopolymers: A Comparative Review

“…Final polymerization of these species gradually synthesizes the SAP geopolymer matrix. Unlike AAS geopolymer, phosphate-bearing crystalline or amorphous phases may occur in some cases when reasonable molar ratios (metal ion to phosphorus) and pH environment are available (Guo et al, 2016).…”

“…The mechanical strengths reported in the published literature varied widely owing to the differences in raw materials (e.g., attribute and recipe), curing condition (e.g., temperature and moisture) and sample preparation technology (e.g., size and age). The 28 days compressive strengths of the geopolymer obtained from literature survey, including low-and high-calcium AAS geopolymers in addition to SAP geopolymers, are shown in Figure 6 (Davidovits, 2011;Chindaprasirt et al, 2012Chindaprasirt et al, , 2013bNath and Kumar, 2013;Nematollahi and Sanjayan, 2014;Atiş et al, 2015;Guo et al, 2016;He et al, 2016;Reddy et al, 2016;Wang et al, 2016;Wang, 2018). Clearly, the statistics showed that the compressive strengths of the AAS geopolymer (i.e., 15-65 MPa for low-calcium series and 70-110 MPa for high-calcium series) significantly outperformed that of the SAP geopolymer (i.e., 10-50 MPa).…”

“…On the other hand, reported that the final setting time was more than 48 h and the compressive strength reached 31 MPa at 28 days for the metakaolin (MK)-based geopolymer activated by mono-aluminum phosphate at room temperature curing. Guo et al (2016) obtained the phosphate-based geopolymer using MK and disused phosphate liquid which resulted in a compressive strength of 62-67 MPa when the matrix experienced 7 days curing at 60 • C. The activating effect of disused phosphate liquid exceeded that of phosphoric acid because of the presence of aluminum ions and thermal curing.…”

“…Thus, such high-connectivity molecular structures of the formed products can perform excellently in terms of strength and durability (Walkley et al, 2017). Later on, the phosphate-activated aluminosilicate was developed and incorporated into the geopolymer category due to the similar condensation process (Liu et al, 2010;Davidovits, 2011;Guo et al, 2016;Wang et al, , 2018b.…”

“…Recently, the AAS geopolymers have been investigated from multiple angles, such as the synthesis mechanism and chemistry (Provis, 2013;Provis and Bernal, 2014;Provis et al, 2015), properties and durability Arbi et al, 2016;Ding et al, 2016), life cycle analysis (Habert et al, 2011;Ouellet-Plamondon and Habert, 2015), and multi-field applications (MacKenzie, 2015;Rao and Liu, 2015;Luukkonen et al, 2019). Yet, the available review related to the SAP geopolymer is limited even though such type of geopolymer was termed as aluminosilicate phosphate cement (Khabbouchi et al, 2017;Katsiki, 2019), phosphoric acid-based geopolymer (Liu et al, 2012;Guo et al, 2016), phosphate-based geopolymer , acid-based geopolymers (Mathivet et al, 2019), and phosphate-bonded materials (MacKenzie, 2015). This paper mainly reviews the development of the SAP geopolymers in reference with the conventional AAS geopolymers.…”