The effects of silica modulus and aging on compressive strength of pumice-based geopolymer composites

Yadollahi, Mehrzad Mohabbi; Benli, Ahmet; Demirboğa, Ramazan

doi:10.1016/j.conbuildmat.2015.07.052

Cited by 94 publications

(32 citation statements)

References 14 publications

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“…For example, the average flexural strength of GPNS-1 nanocomposite improved from 5.8 to 6.2 MPa (6.8% increase). This small but noticeable improvement in mechanical properties can be attributed to the reaction of both alumina and silica during the ageing period in the alkaline environment [38,39]. In a comparable investigation, Rong et al [40] evaluated the effects of the addition of 3.0 wt.% of nano silica on the durability of concrete that contained 35 wt.% fly ash in 28 and 90 days, respectively.…”

Section: Resultsmentioning

confidence: 99%

Influence of Nano Silica Particles on Durability of Flax Fabric Reinforced Geopolymer Composites

et al. 2019

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The durability of natural fibres as reinforcement in geopolymer composites continues to be a matter of concern due to the alkalinity of activators of geopolymer matrices. The alkaline environment is the main reason for natural fibres degradation in cementitious matrices. This paper presents the influence of nano silica (NS) on the durability and mechanical performance of geopolymer composites that are reinforced with flax fabric (FF). The durability investigations were conducted after the storage of samples at ambient temperature for 32 weeks. The study revealed that the addition of nano silica has a positive influence on the physical and mechanical properties of these composites. The presence of NS accelerated the geopolymeric reaction and lowered the alkalinity of the system, thus reducing the degradation of flax fibres.

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Section: Resultsmentioning

confidence: 99%

Influence of Nano Silica Particles on Durability of Flax Fabric Reinforced Geopolymer Composites

et al. 2019

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“…It is categorized as a high energy‐intensive product which releases carbon dioxide (CO 2 ) into the atmosphere during its production . About 40% of CO 2 emissions are produced as a result of building‐related energy consumption and concrete made from ordinary Portland cement (PC) is second only to water as the most material used by mankind today and the cement production contributing for concrete product approximately 10% of global CO 2 emission in the near future . CO 2 emissions are mainly due to fossil fuel burning and limestone decomposition for cement production while grinding and transport are also essential factors in the environmental damage of the cement industry.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of sulfate and salt resistance of ferrochrome slag and blast furnace slag‐based geopolymer concretes

Özcan

Karakoç

2019

Structural Concrete

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In this study, mechanical, visual, and microstructure changes of geopolymer concrete exposed to sulfate and salt effects were investigated. Elazı g ferrochrome slag (EFS) and blast furnace slag (BFS)-based geopolymer concretes which completed curing time were immersed in 5% sodium sulfate (Na 2 SO 4 ), magnesium sulfate (MgSO 4 ), sodium chloride (NaCl), and magnesium chloride (MgCl 2 ) solutions for 12 weeks. The compressive strength values, ultrasonic pulse velocities, visual inspections, weight, and length changes of the samples were determined in this investigation. In addition, scanning electron microscopy was performed for the microstructure analysis of the samples removed from the solutions. Sulfate solutions had a more negative effect on the samples than salt solutions. As the EFS ratio in the mixture increases, the loss rate in the strength of the samples exposed to sulfate and salt solutions decreased. While samples exposed to sodium chloride, sodium sulfate, and magnesium sulfate solutions occurred weight gain, samples exposed to magnesium chloride occurred weight loss. The samples in salt solutions shrank, while the samples in sulfate solutions expanded. No deterioration occurred on the surfaces of the samples exposed to the solutions for 12 weeks. K E Y W O R D S blast furnace slag, chemical resistance, ferrochrome slag, geopolymer concrete, salt effect, sulfate effect

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“…Research findings over the past 10 years revealed that fresh and hardened properties of GP concrete were affected the composition of alkaline activators and their content relative to binding materials, aggregates contents, and sodium hydroxide molarity as well as curing temperature and period . The type and composition of base materials or their blend have crucial impacts upon the polymerization extent of GP composites, hence its internal structure . Hybrid base materials contributed to optimizing Si/Al ratio for best polymerization and mechanical properties; especially for sodium silicate to sodium hydroxide ratios in the range of 2.5–3.0, and sodium hydroxide normality in the range of 10–14 M .…”

Section: Generalmentioning

confidence: 99%

“…The above outlined literature works revealed that the potential of using OSA, as a base material in the production of GP composites, was merely investigated, if none . This work aimed at studying the potential of producing geopolymer mortar (GPM) using Jordanian OSA; considering inherent key parameters, namely concentration of catalysis materials, and alkaline/binder ratios; where the binder (B) represents the solid consistent of sodium hydroxide (NH), sodium silicate (NS), and OSA, and water represents the sum of water in alkaline solutions and water added to maintain consistency.…”

Section: Generalmentioning

confidence: 99%

Producing geopolymer composites using oil shale ash

Haddad

Ashteyat

Lababneh

2018

Structural Concrete

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The potential of producing geopolymer (GP) composites using Jordanian oil shale ash (OSA) was investigated. Twelve GP mortar mixtures were prepared using OSA and different proportions of commercially available alkaline activator, composed of sodium silicate and sodium hydroxide. Prismatic specimens (40 × 40 × 160 mm), attained satisfactory workability, were left at laboratory air for 24 hr, then demolded and dry cured at different practical temperatures (60-100 C) for 24 and 48 hr before left in laboratory air and finally tested for strength and capillary porosity. Furthermore, SEM analysis was carried out on matured GP mortar samples to determine the extent of OSA polymerization and status of pore system. The results indicated the potential of producing GP mortar using OSA with strength grades of as high as 20 MPa. Dry curing at 60 C for 24 hr imparted the best mechanical and durability properties of OSA-based GP mortar. The internal pore structure showed excellent correlation with mechanical and durability properties of produced GP composites. K E Y W O R D S concrete, geopolymer, OSA, porosity, SEM, strength

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The effects of silica modulus and aging on compressive strength of pumice-based geopolymer composites

Cited by 94 publications

References 14 publications

Influence of Nano Silica Particles on Durability of Flax Fabric Reinforced Geopolymer Composites

Influence of Nano Silica Particles on Durability of Flax Fabric Reinforced Geopolymer Composites

Evaluation of sulfate and salt resistance of ferrochrome slag and blast furnace slag‐based geopolymer concretes

Producing geopolymer composites using oil shale ash

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