Strength evaluation by using polycarboxylate superplasticizer and solidification efficiency of Cr 6+ , Pb 2+ and Cd 2+ in composite based geopolymer

Faheem, Muhammad; Huang, Xianghua; Li, Shan; Xia, Ming; Zhang, Manli; Liu, Qiang; Hassan, Muhammad Arshad Shehzad; Jiao, Binquan; Yu, Lin; Li, Dongwei

doi:10.1016/j.jclepro.2018.04.033

Cited by 87 publications

(28 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Many studies have added superplasticizers to calcium-rich precursors, such as blast furnace slag or high-calcium fly ash [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], but the use of superplasticizers in metakaolin- or low-calcium fly ash-based geopolymers activated by sodium hydroxide or silicates is very limited [ 21 , 22 , 23 , 24 ]. In addition, it has not been reported whether plasticizers or superplasticizers applied in geopolymers or alkali-activated materials function as efficiently as when they are applied in cement concrete.…”

Section: Introductionmentioning

confidence: 99%

“…If the flowability is only slightly improved, the use of superplasticizers does not satisfy their original purpose. Superplasticizers can have adverse effects on alkali-activated materials, such as retarding the activation process, failing to improve flowability and even reducing the mechanical strength of alkali-activated slag [ 15 , 16 , 20 , 25 ]. On the other hand, certain superplasticizers are not chemically stable, as evidenced by the precipitation of the sulfonated melamine formaldehyde superplasticizer in a KOH solution [ 26 ], or the rapid degradation in an alkaline environment [ 13 , 27 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Beneficial Use of MIBC in Metakaolin-Based Geopolymers to Improve Flowability and Compressive Strength

et al. 2020

View full text Add to dashboard Cite

Superplasticizers (cement concrete water reducers) are applied to improve the flowability of calcium-rich, alkali-activated materials, with inconsistent results. However, superplasticizer applications are limited in metakaolin-based geopolymers. The possibility of using polycarboxylate superplasticizers and methyl isobutyl carbinol (MIBC) to ameliorate the flowability of metakaolin-based geopolymers was investigated. The ratio of metakaolin, fumed silica, NaOH or KOH, and water in geopolymers at a Na2O or K2O:Al2O3:SiO2:H2O ratio = 1:1:4:10 or 1:1:4:11 was maintained in the formulations. In this study, ether- or ester-based polycarboxylate superplasticizers did not improve the workability of fresh metakaolin-based Na-geopolymers. A low MIBC dose (0.5 wt.% of metakaolin) improved the flowability by 19% and additionally increased the 7-day compressive strength by 22% from 68 to 83 MPa for plain Na-geopolymers. The entrained fine froths produced by adding MIBC during mixing likely reduced friction between metakaolin particles, and the slurry became more workable. Hence, the geopolymer mixture with an improved flowability became more homogenous, which ensured more extensive metakaolin dissolution and hydrolysis. A low MIBC dose could be effective for Na-geopolymers with dual benefits of improved workability and enhanced compressive strength.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Beneficial Use of MIBC in Metakaolin-Based Geopolymers to Improve Flowability and Compressive Strength

et al. 2020

View full text Add to dashboard Cite

show abstract

“…[12][13][14] The dissolution, rearrangement, gelation and crystallization are sequence-wise steps involved in a geopolymerization process. [15][16][17] In addition, geopolymers usually have lower CO 2 emission, lower-cost raw materials, simpler preparation process, more energy-saving ability, much better chemical corrosion resistance and more effective immobilization of toxic HMs when compared with Ordinary Portland Cement (OPC). 11,[18][19][20][21][22][23] The addition of OPC is benecial for the compressive strength development of y ash geopolymers under ambient conditions, which is supported by some studies.…”

Section: Introductionmentioning

confidence: 99%

Solidification of electroplating sludge with alkali-activated fly ash to prepare a non-burnt brick and its risk assessment

Xia

Muhammad

et al. 2020

RSC Adv.

Self Cite

View full text Add to dashboard Cite

show abstract

“…As a result, new environmentfriendly binders must be urgently developed to substitute for OPC [5]. Many studies have demonstrated that geopolymers are promising options to replace OPC [6]. Geopolymers are mainly composed of inorganic materials (constituting aluminosilicates) and alkali activators.…”

Section: Introductionmentioning

confidence: 99%

“…Both are industrial wastes, and recycling of GGBS and FA is resource conserving and environmentally friendly. Although many studies have been performed on geopolymer-stabilized/solidified heavy metals, most of them have focused on the interaction of geopolymers and different types of heavy metal solutions [6][7][8]; few studies are available on geopolymer-stabilized/solidified heavy metalcontaminated soil, and no peer-reviewed literature has methodically investigated the leaching and mechanical properties of heavy metal-contaminated soil treated with GGBS and FA. Recently, the authors have developed a new binder, geopolymer fine aggregate (GFA), which is composed of GGBS, FA, CaO, and Na 2 SiO 3 .…”

Section: Introductionmentioning

confidence: 99%

Mechanical Properties and Leaching Characteristics of Geopolymer‐Solidified/Stabilized Lead‐Contaminated Soil

Zhang

Jia

et al. 2019

Advances in Civil Engineering

View full text Add to dashboard Cite

Ordinary Portland cement (OPC) is widely used in the solidification/stabilization of Pb-contaminated soils. However, many studies have suggested that the high content of Pb would degrade the mechanical properties of OPC-solidified/stabilized soils. is paper presents a new binder, geopolymer fine aggregate (GFA), composed of ground granulated blast furnace slag, fly ash, CaO, and Na 2 SiO 3 . For comparison, OPC was used as a conventional binder. Mechanical properties and leaching characteristics are typically used to evaluate the effects of binders on solidified/stabilized soils. Nevertheless, limited information on the mechanical properties and leaching characteristics of the GFA-solidified/stabilized soils is available. is study thus investigated the mechanical properties and leaching characteristics of geopolymer-solidified/stabilized Pb-contaminated soil. Unconfined compressive strength test, permeability test, synthetic precipitation leaching procedure, simplified bioaccessibility extraction, phytoavailability extraction (with diethylene-triamine penta-acetic acid), sequential extraction procedure, mercury intrusion porosimetry, and scanning electron microscopy (SEM) were performed on OPC-and GFA-solidified/stabilized soil. e results showed that the GFA presented a better effect on the mechanical properties and leachability of the solidified/stabilized soils than the OPC-solidified/stabilized soils. e GFA-solidified/stabilized soil displayed considerably lower leachability, bioaccessibility, and phytoavailability of Pb and higher mechanical properties and chemical stability than the OPC counterpart. is study demonstrated that GFA had a better effect than OPC on the solidification/stabilization of Pb-contaminated soils.

show abstract

Strength evaluation by using polycarboxylate superplasticizer and solidification efficiency of Cr 6+ , Pb 2+ and Cd 2+ in composite based geopolymer

Cited by 87 publications

References 50 publications

Beneficial Use of MIBC in Metakaolin-Based Geopolymers to Improve Flowability and Compressive Strength

Beneficial Use of MIBC in Metakaolin-Based Geopolymers to Improve Flowability and Compressive Strength

Solidification of electroplating sludge with alkali-activated fly ash to prepare a non-burnt brick and its risk assessment

Mechanical Properties and Leaching Characteristics of Geopolymer‐Solidified/Stabilized Lead‐Contaminated Soil

Contact Info

Product

Resources

About