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Prinya Chindaprasirt - One of the best experts on this subject based on the ideXlab platform.

  • resistance to algae and fungi formation of high calcium fly ash Geopolymer Paste containing tio2
    Journal of building engineering, 2019
    Co-Authors: Soebpong Tuntachon, Vanchai Sata, Khanita Kamwilaisak, Theerasak Somdee, Wiyada Mongkoltanaruk, Kornkanok Boonserm, Ampol Wongsa, Prinya Chindaprasirt
    Abstract:

    Abstract In this paper, the resistance to algae and fungi formation on the surface of high calcium fly ash Geopolymer containing nano-titanium dioxide was studied. The compressive strength and density of Geopolymer Paste were also reported. Sodium hydroxide (NaOH)with 10 M concentration, liquid/binder ratio (L/B) of 0.40 and sodium silicate/sodium hydroxide ratio (NS/NH) of 0.67 were used for all mixes. The fly ash was replaced by nano-titanium dioxide at 0, 1, 2, 3, 4 and 5% by weight. A moderate temperature of 40 oC for 48 h was used for the curing of Pastes. The Pastes containing nano-titanium dioxide showed the ability to resist the formation of algae and fungi on the surface of samples. The increasing nano-titanium dioxide content up to 5 %wt significantly increased the ability to resist algae and fungi formations on surface with only slight reductions in compressive strength and density. This indicates the suitability of using high calcium fly ash Geopolymer containing nano-titanium dioxide to solve the problem of algae and fungi formation on the surface.

  • Influence of Glass and Limestone Powders in High Calcium Fly Ash Geopolymer Paste on Compressive Strength and Microstructure
    Key Engineering Materials, 2019
    Co-Authors: Pattanapong Topark-ngarm, Vanchai Sata, Prinya Chindaprasirt
    Abstract:

    The effects of replacing high calcium fly ash with containment glass powder and limestone powder in the Geopolymer are investigated in this paper. The high calcium fly ash was replaced by either glass powder or limestone powder at 20% and 40% by weight. The Geopolymer Paste was tested for setting time and compressive strength and evaluated of its microstructure on SEM, XRD, FTIR, and MIP. The results indicated that the setting time of Geopolymer Paste was increased with the replacement of glass powder and reduced by replacement of limestone powder. The compressive strengths were generally higher than those of controls. The maximum increase of compressive strength was 33% when replaced fly ash with 20% of glass powder at 8 molar NaOH concentration of sodium hydroxide solution. The microstructure evaluations show the remaining particles of raw materials and the compatible of hydration reaction and polymerization when having limestone powder in the mix proportion. Furthermore, the powder acts as a filler in the gels.

  • mechanical properties microstructure and drying shrinkage of hybrid fly ash basalt fiber Geopolymer Paste
    Construction and Building Materials, 2018
    Co-Authors: Wonsiri Punurai, Wunchock Kroehong, Adam Saptamongkol, Prinya Chindaprasirt
    Abstract:

    Abstract This paper evaluates the mechanical properties, microstructure and drying shrinkage of hybrid fly ash-basalt fiber Geopolymer Paste. Fly ash was replaced with basalt fiber at the replacement levels of 0, 10, 20, 30, 40 and 100%. Na2SiO3/NaOH ratio of 1.0 and liquid to binder (L/B) ratio of 0.60 were used for making Geopolymer Pastes. Setting time, strength and drying shrinkage of Geopolymer Pastes were tested. The results showed that the replacement of fly ash with basalt fibers in Geopolymer Pastes resulted in increased setting times and strength and reduced drying shrinkage of Paste. The basalt fiber acted as small reinforcing fibers and enhanced the development of CSH, CASH and NASH which further enhanced the properties of Paste. In addition, the total porosity and critical pore size of fly ash Geopolymer Paste reduce with increasing replacement content in fly ash which makes the Paste more homogeneous and dense compared to fly ash Geopolymer.

  • Effect of Oil Palm Fiber Content on the Physical and Mechanical Properties and Microstructure of High-Calcium Fly Ash Geopolymer Paste
    Arabian Journal for Science and Engineering, 2018
    Co-Authors: Wunchock Kroehong, Thanyawat Pothisiri, Chai Jaturapitakkul, Prinya Chindaprasirt
    Abstract:

    This paper investigates the effect of oil palm fiber content on the physical and mechanical properties and microstructure of high-calcium fly ash Geopolymer Paste. The oil palm fiber was added to the mixture at 0, 1, 2, and 3% by weight of fly ash. Sodium hydroxide (NaOH) and sodium silicate $$(\hbox {Na}_{2}\hbox {SiO}_{3})$$ ( Na 2 SiO 3 ) were used as liquid alkaline activators. The bulk density, compressive strength, flexural strength, pore size distribution, scanning electron microscopy, and thermal conductivity of Geopolymer Paste were determined. Test results showed that the bulk density of high-calcium Geopolymer Paste containing oil palm fibers decreased with increasing fiber content. The increase oil palm fiber content decreased the compressive strength of Geopolymer Paste but enhanced the flexural strength and toughness and changed the failure behavior of Geopolymer composite. In addition, the pore size and total porosity also increased with the increase in fiber content, while the thermal conductivity was reduced. The addition of oil palm fiber can improve the flexural strength and thermal conductivity of Geopolymer Paste and could thus be developed into a fiber-reinforced composite for construction purposes.

  • Development of Thai Lignite Fly Ash and Metakaolin for Pervious Geopolymer Concrete
    Key Engineering Materials, 2018
    Co-Authors: Sarochapat Sutikulsombat, Chayanee Tippayasam, Thapanee Srichumpong, Phachongkit Boonanunwong, Prinya Chindaprasirt, Cristina Leonelli, Duangrudee Chaysuwan
    Abstract:

    The study was to use Thai lignite fly ash and metakaolin to produce Geopolymer Paste as binder material in pervious concrete. The proper ratio of fly ash to metakaolin were varied as 100:0, 70:30, and 50:50. Alkali solution to pozzolan (L/P) ratios viz., 0.5, 0.6 and 0.8 by weight were prepared. The mechanical and characterization of pervious Geopolymer concrete (PGC) were carried out. The results presented that the particle of fly ash was sphere with smooth surface, while metakaolin was partly agglomerated and irregular shaped. The increase of fly ash in the ratio of fly ash to metakaolin affected the lower requirement of volume of alkali solution. The compressive strength and of pervious Geopolymer concrete at 28 days were 3.74-5.41. The void ratio and water permeability were 28.54-30.74% and 1.90-2.09 cm/sec, respectively. Therefore, Geopolymer Paste from fly ash and metakaolin could be used for pervious concrete with satisfied properties. However, the price of pervious cement concrete is 1,898-2,168 THB/m3, while the price of pervious Geopolymer concrete is 2,123-4,173 THB/m3 due to the energy cost to transform kaolin into metakaolin by an electric furnace. The cost can be reduced by increasing the ratio of fly ash to metakaolin.

Shan Li - One of the best experts on this subject based on the ideXlab platform.

  • physical and mechanical properties and micro characteristics of fly ash based Geopolymer Paste incorporated with waste granulated blast furnace slag gbfs and functionalized multi walled carbon nanotubes mwcnts
    Journal of Hazardous Materials, 2021
    Co-Authors: Faping Li, Zheming Yang, Shan Li
    Abstract:

    Abstract Geopolymers are highly durable and have favorable mechanical properties, and are thus regarded as an eco-friendly alternative to traditional ordinary Portland cement binder. In this study, MWCNTs are obtained through a modification method using a compound of nitric acid and sulfuric acid, and are then dispersed using three types of dispersants. Fly ash-based Geopolymers are prepared to validate the effectiveness and feasibility of adopting 0.05 wt.%, 0.10 wt.%, and 0.15 wt.% functionalized MWCNTs and substitution ratios of 10 %–40 % of fly ash with GBFS. The structure and dispersity of the functionalized MWCNTs in aqueous solutions are characterized using FT-IR and TEM, respectively. Then, the setting time, water absorption capacity, and mechanical behaviors are evaluated. In addition, SEM-EDS, FT-IR, TG-DSC, 29Si NMR, and XRD are employed to investigate the morphology, elemental components, mineralogical phases, and Geopolymerization degree of the gel products. The experimental results show that the functionalized MWCNTs comprise −COOH and −OH groups and can be uniformly dispersed in aqueous solution containing SDS dispersant. Furthermore, Geopolymer Paste incorporated with 0.1 wt.% functionalized MWCNTs and having 30 % substitution of fly ash with GBFS exhibits a higher compressive and flexural strength and a lower water absorption capacity compared with all other Geopolymer Pastes.

  • Physical and mechanical properties and micro characteristics of fly ash-based Geopolymer Paste incorporated with waste Granulated Blast Furnace Slag (GBFS) and functionalized Multi-Walled Carbon Nanotubes(MWCNTs)
    Journal of Hazardous Materials, 2020
    Co-Authors: Faping Li, Zheming Yang, Shan Li
    Abstract:

    Abstract Geopolymers are highly durable and have favorable mechanical properties, and are thus regarded as an eco-friendly alternative to traditional ordinary Portland cement binder. In this study, MWCNTs are obtained through a modification method using a compound of nitric acid and sulfuric acid, and are then dispersed using three types of dispersants. Fly ash-based Geopolymers are prepared to validate the effectiveness and feasibility of adopting 0.05 wt.%, 0.10 wt.%, and 0.15 wt.% functionalized MWCNTs and substitution ratios of 10%-40% of fly ash with GBFS. The structure and dispersity of the functionalized MWCNTs in aqueous solutions are characterized using FT-IR and TEM, respectively. Then, the setting time, water absorption capacity, and mechanical behaviors are evaluated. In addition, SEM-EDS, FT-IR, TG-DSC, 29Si NMR, and XRD are employed to investigate the morphology, elemental components, mineralogical phases, and Geopolymerization degree of the gel products. The experimental results show that the functionalized MWCNTs comprise -COOH and -OH groups and can be uniformly dispersed in activating solution containing SDS dispersant. Furthermore, Geopolymer Paste incorporated with 0.1 wt.% functionalized MWCNTs and having 30% substitution of fly ash with GBFS exhibits a higher compressive and flexural strength and a lower water absorption capacity compared with all other Geopolymer Pastes.

Zuhua Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Quantification of chloride diffusion in fly ash-slag-based Geopolymers by X-ray fluorescence (XRF)
    Construction and Building Materials, 2014
    Co-Authors: Tao Yang, Zuhua Zhang
    Abstract:

    Abstract Chloride diffusion in cementitious materials is one of the key factors affecting the durability performance of concretes. This paper reports an investigation on the quantification of chloride diffusion in fly ash–slag-based Geopolymer Pastes. X-ray fluorescence (XRF) technique was used to determine the chemical compositions of the samples after short-term ponding test (contact with the 3% NaCl solution for 72 h). The effect of the coexistence of Al-substituted calcium silicate hydrate (C-A-S-H) gel and aluminosilicate Geopolymeric gel on the ingress of chloride was evaluated. The results showed that incorporation of slag as a secondary precursor in fly ash-based Geopolymers led to the refinement of the pore structure, reducing both sorptivity of the Pastes and the ingress of chloride ions. More compact C-A-S-H gel formed in Geopolymer Pastes with partial slag substitution led to lower permeability compared with the porous aluminosilicate gel that formed in the full fly ash-based Geopolymer Paste, contributing to the slower transportation of chloride in the fly ash–slag blended Geopolymer Pastes. The fly ash–slag-based Geopolymer Paste with 50% of slag performed better than the Portland cement Paste in terms of resistance to chloride ingress.

  • Quantification of chloride diffusion in fly ash-slag-based Geopolymers by X-ray fluorescence (XRF)
    Construction and Building Materials, 2014
    Co-Authors: Xiao Yao, Zuhua Zhang
    Abstract:

    Chloride diffusion in cementitious materials is one of the key factors affecting the durability performance of concretes. This paper reports an investigation on the quantification of chloride diffusion in fly ash-slag-based Geopolymer Pastes. X-ray fluorescence (XRF) technique was used to determine the chemical compositions of the samples after short-term ponding test (contact with the 3% NaCl solution for 72 h). The effect of the coexistence of Al-substituted calcium silicate hydrate (C-A-S-H) gel and aluminosilicate Geopolymeric gel on the ingress of chloride was evaluated. The results showed that incorporation of slag as a secondary precursor in fly ash-based Geopolymers led to the refinement of the pore structure, reducing both sorptivity of the Pastes and the ingress of chloride ions. More compact C-A-S-H gel formed in Geopolymer Pastes with partial slag substitution led to lower permeability compared with the porous aluminosilicate gel that formed in the full fly ash-based Geopolymer Paste, contributing to the slower transportation of chloride in the fly ash-slag blended Geopolymer Pastes. The fly ash-slag-based Geopolymer Paste with 50% of slag performed better than the Portland cement Paste in terms of resistance to chloride ingress. © 2014 Elsevier Ltd. All rights reserved.

Mohd Mustafa Al Bakri Abdullah - One of the best experts on this subject based on the ideXlab platform.

  • photocatalytic activity of zno doped Geopolymer Paste
    IOP Conference Series: Materials Science and Engineering, 2020
    Co-Authors: Siti Norsaffirah Zailan, Norsuria Mahmed, Mohd Mustafa Al Bakri Abdullah
    Abstract:

    This study aims to investigate the photocatalytic activity of ZnO nanoparticles as photocatalyst material which was doped onto a Geopolymer Paste. ZnO-doped Geopolymer Paste were prepared by mixing Class F fly ash and various amount of ZnO nanoparticles with alkali activator, which is combination of sodium hydroxide solution with sodium silicate. Meanwhile, Geopolymer Paste without ZnO was produced by mixing Class F fly ash and alkali activator. Then, both samples were cured in room temperature and aged for 28 days. The photocatalytic activity for Geopolymer Paste with and without ZnO nanoparticles were evaluated and compared through photocatalytic testing and discolouration testing. The experimental results revealed that, as increasing the amount of addition ZnO nanoparticles, the degradation of methylene blue also was increased. However, mineralogical determination of ZnO-doped Geopolymer Paste were characterized using X-ray Diffraction (XRD).

  • bonding strength characteristics of fa based Geopolymer Paste as a repair material when applied on opc substrate
    Applied Sciences, 2020
    Co-Authors: Warid Wazien Ahmad Zailani, Mohd Mustafa Al Bakri Abdullah, Aissa Bouaissi, Rafiza Abd Razak, Sorachon Yoriya, Mohd Arif Anuar Mohd Salleh, M Mohd Remy A Z Rozainy, Hamzah Fansuri
    Abstract:

    This investigative study aims to study the mechanical and morphological properties of fly ash (FA)-based Geopolymer Paste as a repair material when applied on ordinary Portland cement (OPC) overlay concrete. The first part of this study investigates the optimal mix design of FA-based Geopolymer Paste with various NaOH concentrations of 8, 10, 12, and 14 M, which were used later as a repair material. The second part studies the bonding strength using a slant shear test between the Geopolymer repair material and OPC substrate concrete. The results showed that a shorter setting time corresponds to the higher NaOH molarity, within the range of 53 and 30 min at 8 and 14 M, respectively. The compressive strength of FA-based Geopolymer Paste was found to reach 92.5 MPa at 60 days. Also, from the slant shear test results, prism specimens with 125 mm length and 50 mm wide have a large bond strength of 11 MPa at 12 M. The scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) analysis showed that the OPC substrate has a significant effect on slant shear bond strength, where the presence of free cations of Ca2+ on the OPC substrate surface contributed to the formation of calcium alumina-silicate hydrate gel (C-A-S-H) by building various cross-links of Ca-O-Si.

  • effect of different ratio of Geopolymer Paste based fly ash metakaolin on compressive strength and water absorption
    Microelectronics Systems Education, 2019
    Co-Authors: Nor Shida Dalila Mohd Azhar, Farah Farhana Zainal, Mohd Mustafa Al Bakri Abdullah
    Abstract:

    This paper presents the effect of different solid to solid (S/S) ratio by mixing the fly ash and metakaolin as Geopolymer Paste on the compressive strength and water absorption. Fly ash is a waste materials produced by combustion of coal at power plant while metakaolin was obtained by calcining the kaolin at 750 °C for 4 hours. Different weight percentage of S/S ratio of fly ash/metakaolin used were 50%:50% (Mix 1), 70%:30% (Mix 2) and 90%:10% (Mix 3). Alkaline activators that act as binder were sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) solutions. The ratio of Na2SiO3/NaOH is 2.5 to 1. The mixture then placed into cylinder mould and left for 7, 14 and 28 days before it be tested. The product obtained were observed and it shows that Mix 2 has highest compressive strength for 28 days that was 41.22 MPa and has lower water absorption. The pore size decreases and permeability also decreases hence the strength potentially improve.

  • Influence of ZnO Nanoparticles on Mechanical Properties and Photocatalytic Activity of Self-cleaning ZnO-Based Geopolymer Paste
    Journal of Inorganic and Organometallic Polymers and Materials, 2019
    Co-Authors: Siti Norsaffirah Zailan, Norsuria Mahmed, Aissa Bouaissi, Mohd Mustafa Al Bakri Abdullah
    Abstract:

    The influence of zinc oxide (ZnO) nanoparticles on the mechanical properties and photocatalytic degradation of methylene blue (MB) of ZnO-based Geopolymer material was investigated under the illumination of ultraviolet (UV) radiations. In this work, ZnO-based Geopolymer Paste was manufactured using class F fly ash (FA) and ZnO nanoparticles powders with different mass percentages (0, 2.5, 5.0, 7.5 and 10 wt%). The FA-ZnO dry mix was activated by alkaline activator solution made from sodium silicate and sodium hydroxide with a ratio of 2.5. The mechanical properties were investigated by performing a compressive strength test at 28 days. The photocatalytic activity of ZnO nanoparticles was evaluated by measuring the photodegradation level of methylene blue under sunlight rays. The results showed a substantial influence of ZnO on the compressive strength, which decreased with the increase of ZnO amounts ranging from 2.5 to 7.5 wt% then a slightly increased at 10 wt% of ZnO. The addition of ZnO nanoparticles to a Geopolymeric material showed a satisfactory efficiency of photocatalytic degradation of methylene blue after 150 min of exposure to sunlight. Phase analysis revealed that the addition of ZnO nanoparticles in the Geopolymeric system develops a new ZnO crystalline phases. Graphic Abstract

  • Effect of Geopolymer coating on mild steel
    Solid State Phenomena, 2018
    Co-Authors: Farah Farhana Zainal, Mohd Mustafa Al Bakri Abdullah, Kamarudin Hussin, Azmi Rahmat, Muhammad Faiz Fazill, Warid Wazien
    Abstract:

    This paper presents the results of a study on the effect of Geopolymer coating on mild steel. Geopolymer is synthesis of a fly ash and alkaline activators which are sodium hydroxide solution (NaOH) and sodium silicate solution (Na2SiO3). Fly ash is one of residue produced during the combustion of coal in coal power plant. In this study, fly ash class F based Geopolymer was used as a source material. The alkaline activators then were mixed with fly ash to produce the Geopolymer Paste which acts as a coating material. The mixture was placed in molds and reinforcement bar were embedded in Geopolymer Paste. After that, the corrosion behavior of reinforcement bars for all samples were observed by using Open Circuit Potential (OCP) testing. Referring the pourbaix diagram regarding OCP testing, samples are in passivity region. Besides that, mild steel also were coated with Geopolymer Paste for adhesion test. Elcometer 108 was used for adhesion strength test. Morphology analysis also been used to determine the microstructure of fly ash and Geopolymer Paste. Phase analysis was used for the analysis phase between fly ash, Geopolymer Paste and mild steel coated with Geopolymer Paste. From OCP test, pourbaix diagram shows that samples is placed in the passivity region, iron (III) oxide (Fe2O3) which is in stable phase and iron (II, III) oxide same results as in phase analysis. The minimum potential value for OCP is 0.015 V and the maximum potential value is 0.133 V. For adhesion strength, day 14 got the highest results compared day 7 and day 3 which the results are 2.0 Mpa, 1.9 Mpa and 1.5 Mpa respectively. It is because from day 3 until day 14, the structure of Geopolymer Paste becomes more compact, denser and better crystallization as shown in morphological analysis.

C Rajasekaran - One of the best experts on this subject based on the ideXlab platform.

  • An Experimental Investigation to Determine the Properties of Fly Ash Based Geopolymers as per Indian Standards
    Lecture Notes in Civil Engineering, 2018
    Co-Authors: Suman Saha, C Rajasekaran
    Abstract:

    Production of ordinary Portland cement requires huge quantity of natural resources and also releases huge quantity of carbon dioxide into the atmosphere. Research efforts have been continuing to establish Geopolymer as an alternative cementitious material for the replacement of ordinary Portland cement. This paper presents the study to find out the properties of fly ash based Geopolymer Paste and 28 days compressive strength of Geopolymer mortar. Standard consistency, setting time of Geopolymer Paste has been determined using vicat’s apparatus (according to Indian Standards), which is followed for cement Paste, varying the concentration of sodium hydroxide solution from 6 to 16 M. Results indicate higher standard consistency, more time required for setting for fly ash based Geopolymer than that of cement Paste. Compressive strength of the Geopolymer Paste and mortar 17 specimens increases with the increase of the concentration of sodium hydroxide solution and decrease beyond 14 M.

  • enhancement of the properties of fly ash based Geopolymer Paste by incorporating ground granulated blast furnace slag
    Construction and Building Materials, 2017
    Co-Authors: Suman Saha, C Rajasekaran
    Abstract:

    Abstract Research efforts have been made continuously to establish fly ash based Geopolymer as an alternative binder material for the production of fresh concrete because production of Ordinary Portland Cement degrades the environment by huge emissions of carbon-di-oxide and also by consuming lot of natural resources. But most of the study reveals, fly ash based Geopolymer Paste needs more time to get set when it is cured at ambient temperature. As a result, it is quite impractical to use fly ash based Geopolymer Paste as an alternative to Ordinary Portland Cement in faster construction. In this study, an effort has been made to enhance the properties of fly ash based Geopolymer Paste by incorporating ground granulated blast furnace slag at various percentage levels. Microstructure of the Geopolymer Paste is studied using Scanning Electron Microscopy. Result of this investigation shows that significant improvement on setting time and compressive strength can be obtained by adding ground granulated blast furnace slag in the mixes.