Performance of geopolymer mortar cured under ambient temperature

Khalil, Mohamed; Elgabbas, Fareed; El-Feky, M.S.; Elshafie, Hany

doi:10.1016/j.conbuildmat.2020.118090

Cited by 53 publications

(8 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…MK and GGBFS exhibited amorphous peaks at 2θ values of 15–35° and 25–35°, respectively. Additionally, a small amount of quartz was present in MK, as found in previous studies [ 28 ]. After the geopolymeric reaction, a newly formed phase at 2θ of 29.3°, representing the C-(A)-S-H network [ 17 , 43 ], occurred in all the formulations.…”

Section: Resultssupporting

confidence: 77%

“…In terms of the effect of the character and amount of alkaline activators on the macroscopic properties of geopolymer pastes, Khalil et al [ 28 ] studied the effects of the L/S ratio and the alkaline activator modulus on the compressive strength of MK/GGBFS-blended geopolymer with a GGBFS content of 50%. The increase in modulus from 1.1 to 1.7 or the increase in the L/S ratio from 0.5 to 0.7 decreased compressive strength.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Investigation of Setting Time and Microstructural and Mechanical Properties of MK/GGBFS-Blended Geopolymer Pastes

et al. 2022

View full text Add to dashboard Cite

In this study, geopolymer pastes with 60% metakaolin (MK) and 40% ground granulated blast-furnace slag (GGBFS) were synthesized. To determine the influence of the alkaline activator concentration, modulus, and the liquid/solid (L/S) ratio on setting time and compressive strength, the geopolymerization process and microstructures of MK/GGBFS-blended geopolymer pastes were analyzed using isothermal calorimetry, X-ray diffraction, mercury intrusion porosimetry, and scanning electron microscopy. Acid dissolution was employed to measure reaction extent. The results showed that the initial setting time of the geopolymer pastes was between 68 and 226 min, and the initial setting and final setting time was apart about by 10 min. For the same variable, the total heat released was positively correlated to the reaction extent. Available silicate content increased the reaction rate and intensity at the initial stage, whereas the OH− concentration controlled the reaction extent in the long term. A limited reaction extent existed in the geopolymeric reaction even if the system contained sufficient alkali content and medium. An increase in the L/S ratio increased the reaction extent. The highest reaction extent of 86.3% was found in the study. Additionally, increasing the L/S ratio reduced the compressive strength by increasing the porosity.

show abstract

Section: Resultssupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Investigation of Setting Time and Microstructural and Mechanical Properties of MK/GGBFS-Blended Geopolymer Pastes

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Although some studies show that hot cured geopolymers have better compressive strengths than geopolymers cured at ambient temperature [153][154][155], the latter can also exhibit high compressive strengths [156,157], as shown in a study by Khan et al [158], where a compressive strength of 108 MPa was obtained with an alkali activated material based on fly ash and slag. Some authors have studied the effect of using seawater for the manufacture of alkaline activated geopolymers [159], where it has been observed that the use of salt water tends to improve the compressive strength of geopolymers cured at room temperature [160].…”

Section: Curing Temperature and Timementioning

confidence: 99%

Factors Affecting the Compressive Strength of Geopolymers: A Review

et al. 2021

View full text Add to dashboard Cite

Geopolymers are created by mixing a source of aluminosilicates, which can be natural or by-products from other industries, with an alkaline solution. These materials based on by-products from other industries have proven to be a less polluting alternative for concrete production than ordinary Portland cement (OPC). Geopolymers offer many advantages over OPC, such as excellent mechanical strength, increased durability, thermal resistance, and excellent stability in acidic and alkaline environments. Within these properties, mechanical strength, more specifically compressive strength, is the most important property for analyzing geopolymers as a construction material. For this reason, this study compiled information on the different variables that affect the compressive strength of geopolymers, such as Si/Al ratio, curing temperature and time, type and concentration of alkaline activator, water content, and the effect of impurities. From the information collected, it can be mentioned that geopolymers with Si/Al ratios between 1.5 and 2.0 obtained the highest compressive strengths for the different cases. On the other hand, high moderate temperatures (between 80 and 90 °C) induced higher compressive strengths in geopolymers, because the temperature favors the geopolymerization process. Moreover, longer curing times helped to obtain higher compressive strengths for all the cases analyzed. Furthermore, it was found that the most common practice is the use of sodium hydroxide combined with sodium silicate to obtain geopolymers with good mechanical strength, where the optimum SS/NaOH ratio depends on the source of aluminosilicates to be used. Generally speaking, it was observed that higher water contents lead to a decrease in compressive strength. The presence of calcium was found to be favorable in controlled proportions as it increases the compressive strength of geopolymers, on the other hand, impurities such as heavy metals have a negative effect on the compressive strength of geopolymers.

show abstract

“…It's also utilized as a fire retardant and an insulator. Some of these wastes (such as fly ash and smelting iron slag) are presently solely utilized as pozzolans in Portland cement manufacturing [45][46][47].…”

Section: Applications and Properties Of Geopolymersmentioning

confidence: 99%

The features of geopolymer concrete as a novel approach for utilization in green urban structures

Esparham

Ghalatian

2022

jcc

View full text Add to dashboard Cite

Because of its unique qualities, concrete is the second most commonly utilized building material after water.However, there are significant downsides to the Portland cement manufacturing process, producing one ton of carbon dioxide per every ton of Portland cement. As a result, the usage of a Portland cement substitute appears to be required. On the other hand, the "waste-free" idea and the manufacturing of new materials with an environmental impact will be less important in future cities than the aims of sustainable development. To further develop environmentally friendly materials, it is vital to understand the environmental stimuli of novel materials as well as to assess the environmental effects of standard building materials. Geopolymers are ceramic-like materials with three-dimensional poly-compact structures that are made by chemically activating aluminum and silica-containing solids at low temperatures. Industrial wastes or by-products like coal combustion ash, smelting iron furnace slag, construction debris, or agricultural waste like rice husk ash can be utilized to make geopolymer concrete and construction. The present article reviews the studies on the use of geopolymer technology in sustainable materials to develop urban sustainability and reduce the emission of environmental pollutants with a life cycle assessment approach. Findings and results of studies show that geopolymer concretes have higher mechanical, chemical, and energy consumption properties than conventional concrete and offer significant environmental benefits.

show abstract

Performance of geopolymer mortar cured under ambient temperature

Cited by 53 publications

References 19 publications

Investigation of Setting Time and Microstructural and Mechanical Properties of MK/GGBFS-Blended Geopolymer Pastes

Investigation of Setting Time and Microstructural and Mechanical Properties of MK/GGBFS-Blended Geopolymer Pastes

Factors Affecting the Compressive Strength of Geopolymers: A Review

The features of geopolymer concrete as a novel approach for utilization in green urban structures

Contact Info

Product

Resources

About