·As for the ratio between the fly ash activator solution as with the water/cement factor in traditional cementitious mixtures the lower the mass ratio between the activator solution and fly ash the higher the strength results Where the alkaline activator refers to the Na 2 O and the effective SiO 2 of the alkaline solution
·The environmental impact from the production of cement has prompted research into the development of concretes using 100 % replacement materials activated by alkali solutions This paper reports the assessment of a number of key durability parameters for geopolymer concrete made from fly ash activated with sodium silicate and sodium hydroxide
·Fly Ash Based Aqueous Nanosilica Enhanced Activator for Efficient Production of Room Temperature Cured Concrete with Two Part Alkali Activated Binders Gao X Q L Yu A Lazaro and H J H Brouwers 2017 Investigation on a green olivine nano silica source based activator in alkali activated slag fly ash blends Reaction
·The dispersion of fly ash in water results in an alkaline pH from 10 to 13 At high pH the fly ash becomes negatively charged allowing the removal of heavy metal ions by precipitation and electrostatic adsorption from water Cho et al 2005 Fly ash can be modified or transformed into new materials for heavy metal ions adsorption
·To examine the utilization of fly ash and GGBS as a cement substitute it is necessary to study the standard consistency and setting time of geopolymer paste and workability as well as compressive strength of alkali activated fly ash and slag based geopolymer concrete The method used to determine these tests was the same as used for cement
·In this paper an investigation related to the rheological behaviour of alkali activated fly ash pastes AAFA is described Those pastes were prepared by mixing the fly ash with an alkaline dissolution containing 85% of a M NaOH solution and 15% of waterglass and adding some commercial chemical admixtures usually used in the Portland cement concrete
·Commercially available low calcium Class F fly ash was used as the main binder Ground granulated blast furnace slag GGBFS was used as a partial replacement of fly ash in this study The chemical compositions of the fly ash and GGBFS determined by X Ray Fluorescence XRF are given in Table 1 The alkaline activator was a combination of
·The results indicate that the optimal mix proportion for HSGPC includes 15% fly ash content % silica fume content alkali activator ratio of and a NaOH molar concentration of 10 M
·A large range of slump flow from to cm and setting time from 10/46 to 84/133 min can be caused by both slag/fly ash ratio and activator modulus Increasing the fly ash content in the slag fly ash mix leads to an increased slump flow and prolonged initial/final setting time; while an increase of the activator modulus results in an
·Fly ash based geopolymer concrete completely moves away from OPC and the high CO 2 emission associated with OPC production Cakir and Akoz 2008 Aldea et al 2000 Habert et al 2011 Fly ash based geopolymer itself is a good binder that can be used as cement to mix with aggregates to produce the geopolymer concrete
·The results confirm that the compressive strength of one part geopolymer pastes increased by increasing the Na2O content of the alkaline source and the slag dosage; however increasing the Na2O content in alkaline sources beyond 6% by fly ash weight led to decreasing the compressive strength; therefore the optimum alkaline activator dosage by
·The combination mass ratios of fly ash/alkaline activator and Na2SiO3/NaOH of and respectively produced the highest compressive strength after seven days Geopolymer samples cured at 60
· Soil fly ash & activator The soil used for the testing program was a clayey soil utilized from the Kaolin Company in Puchong /Kuala Lumpur Its physical properties were conducted
·The use of geopolymer as a cementitious material for geopolymer concrete GPC is beneficial for the sustainable development and green transformation of the construction industry Geopolymer concrete has many advantages such as high strength heat and corrosion resistance low hydration heat and carbon emissions This paper adopted the water binder
This study aims to develop fly ash clay brick alkali activated mixtures suitable as sustainable porous building materials [15] [16] [17] [18] Clay brick waste material rich in silicates and aluminates will partially replace fly ash along with alkali activators to produce porous AAM binder systems [19] The effects of brick content on the formation of porous structure
·They concluded that fly ash FA blast furnace slag BFS metakaolin MK rice husk ash RHA and palm oil fuel ash The effects of ground granulated blast furnace slag blending with fly ash and activator content on the workability and strength properties of geopolymer concrete cured at ambient temperature Mater Des 62 2014 pp 32 39
·This study is focused on the effects of Class C fly ash FA NaOH/Na2SiO3 SH/SS ratio and steel fiber STF on the freeze thaw F T cycle sulfuric acid thermal conductivity and impact resistance of silica fume SF based alkali activated high
·This study reports the changes in the compressive strength and shrinkage property of alkali activated fly ash and slag AAFS blends associated with efflorescence The AAFS specimens cured in air for different periods were further aged under the following three conditions bottom contact with water fully immersed in water and in air The second condition
·The shrinkage of AAM is an important engineering property influencing the cracking probability of AAM under the restrained condition The previous studies [10] [11] showed that the alkali activated slag had a significantly higher autogenous and drying shrinkage than the ordinary Portland cement OPC It was also reported that the activator species and dosage
·It is also important to validate the predictive technique against different sources of fly ash type of activator and curing conditions used Nevertheless the results show that the K value can be a powerful tool for evaluating and ranking fly ashes for production of
·Traditional silicate cement materials produce a large amount of CO2 during production making it urgent to seek alternatives Alkali activated slag cement is a good substitute as its production process has low carbon emissions and energy consumption and it can comprehensively utilize various types of industrial waste residue while possessing superior
·It is also important to validate the predictive technique against different sources of fly ash type of activator and curing conditions used Nevertheless the results show that the K value can be a powerful tool for evaluating and ranking fly ashes for production of
·Sodium silicate solution Na 2 SiO 3 and sodium hydroxide NaOH at a concentration of 15 molars were combined as the liquid alkaline activator AA The effect of different fly ash to alkaline
·Composites that use fly ash and slag as alkali activated materials instead of cement can overcome the defects and negative effects of alkali activated cementitious materials prepared with the use of an alkali activated material In this study fly ash and slag were used as raw materials to prepare alkali activated composite cementitious materials Experimental
