Analysis of the production conditions of geopolymer matrices from natural pozzolana and fired clay brick wastes (original) (raw)
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Application of Clay - Based Geopolymer in Brick Production: A Review
Advanced Materials Research, 2012
This paper reviews and summarizes the current knowledge and application of clay as a geopolymer material in production of geopolymer brick. As we understand, the nature of source materials give a significant impact to the strength of geopolymer. For example, geopolymer made from calcined source material such as calcined kaolin, fly ash, ground granulated blastfurnace slag (GGBS) and others produce a higher compressive strength compared to geopolymer made from non-calcined source material such as kaolin. This paper is reviewing on the suitability of clay application as a geopolymer material in geopolymer brick production. The chemical composition of clay-based material show high content of SiO 2 and Al 2 O 3 compound which is similar to the fly ash. Clay-based Geopolymer showed a good potential in a brick production.
Journal of sustainable construction materials and technologies, 2022
The applications of geopolymers as cementitious systems are becoming an alternative source of cement daily. The use of potentially suitable aluminosilicate inorganic waste materials incorporated with agro-industrial waste in the production of suitable geopolymer binders has been reported. Calcined clay and some agro-waste ash, such as coconut shells, are examples of aluminosilicate materials that exhibit strong pozzolanic activity because of their high silica-alumina composition. The pozzolanic reaction is primarily caused by the amorphous silica present in properly burned agricultural waste and clay. Based on a variety of available literature on concrete and mortar including geopolymers synthesized from the by-product and agro-industrial waste and natural pozzolan, a critical review of raw materials and the mechanism of synthesis of the geopolymer has been outlined in this work. Also, a brief review of the durability characteristics of this geopolymer concrete and mortar has been done. These include resistance to chloride, corrosion, sulphate and acid attack, depth of carbonation, thermal performance, Creep and drying shrinkage.
Journal of Materials Research and Technology, 2021
In this research, the use of olive pomace fly ash (OPFA) as an alkaline source for the activation of calcined clays (CC) from Bail en (Ja en, Spain) was studied. The optimal composition was obtained for 70 wt % CC and 30 wt % OPFA. The physical, mechanical and thermal properties of control geopolymers that use water as a liquid medium have been studied and compared with geopolymers that use additional activating solutions as sodium or potassium hydroxide solutions (8 M), or a mixture of alkaline hydroxide and alkaline silicate solution (NaOHeNa 2 SiO 3 or KOHeK 2 SiO 3). The results showed that OPFA can be used as an alkaline activator, showing mechanical properties slightly lower than those obtained when additional alkaline hydroxide activating solutions were used. The best compressive strength was obtained for geopolymers that use alkaline silicates as an activating solution. However, the best thermal insulation properties were obtained for control geopolymers. The microstructural characteristics of the geopolymers were evaluated by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM-EDS) that corroborate the formation of geopolymeric gel in all the specimens, being the amount of gel formed greater in samples using commercial potassium activating solutions. These results demonstrate the feasibility of using this type of waste, OPFA, as activating reagents in the manufacture of geopolymers or alkaline activated materials. The manufactured geopolymers can be used as compressed earth blocks for walls and partitions, since the specimens pursue mechanical properties that comply with current regulations, presenting better thermal insulation properties.
Analysis of Soil Samples for Development of Geopolymer Materials for Brick Manufacturing
In the process of cement production a lot of CO 2 is produced, this leads to environmental pollution and contribute to global warming and depletion of ozone layer.Geopolymers are among alternativematerials that are examinedfor the purpose ofreducing the production ofcement for brick manufacturing. Aluminum and silicon-containing compound (aluminosilicate), most likely geological in origin, could react in a polymerization process with an alkaline solution at ambient conditions to create a geopolymer material. Geopolymer technology has the potential to reduce CO 2 emission by 80%, because high temperature calcining applied in cement production is not needed. The primary objective of this study wasto analyse soil samples for development of geopolymer materials suitable for manufacturing construction bricks.Different soil samples were collected from different areas in Arusha. Laboratory analysis was done to identify the physical and chemical properties. Arusha soils have shown better properties that can be used in the manufacture of geopolymer bricks. The soil analysis showed good mechanical properties and suitable chemical composition in terms of SiO 2 , Al 2 O 3 and Fe 2 O 3 which are the basic compounds in the manufacture of geopolymer materials.
Effect of calcination temperature of tunisian clays on the properties of geopolymers
Ceramics Silikaty
Geopolymers are amorphous three dimensional aluminosilicate materials that may be synthesized at room or slightly higher temperature by alkaline activation of aluminosilicates obtained from industrial wastes, calcined clays and natural minerals. Among the different family of geopolymers, two Tunisian clays (a kaolinite clay from Tabarka and illito/kaolinitic clay from Medenine) are tested for their feasibility of geopolymers at low temperature. The unfired and calcined clays were dissolved in strongly alkaline solution in order to produce consolidated materials whose pastes were characterized by their compressive strength. Hardened geopolymer samples were also submitted to X-Ray diffraction, FTIR spectroscopy and scanning electron microscopy analyses. The geopolymer strength is related to the structure and reactivity of the clay generated by thermal treatment and to the role of associated minerals in clays. The amorphous character of obtained geopolymers and the displacement of the ...
Comparative Study of the Geopolymers Synthesized from Various Types of Construction Wastes
Nepal Journal of Science and Technology, 2013
Demolition of old houses and construction of new buildings are in peak in urban sectors which generate a huge amount of construction wastes. These wastes are rich source of alumino-silicate. Geopolymerization can transform a wide range of alumino-silicate materials into building materials with excellent physicochemical properties. Thus, geopolymers have been synthesized from construction wastes such as sand-cement-mixture (SCM), concrete mixture (CM), brick dust (BD), etc using alkali and alkali-silicate as activators. Parameters like alkali concentration (for dissolution of alumino-silicate), ratio of alkali-silicate to construction wastes and curing time were varied to improve the quality of geopolymeric products. The maximum compressive strengths of geopolymeric products obtained from BD, SCM and CM were 60.0, 47.0 and 45.5 MPa respectively. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 81-86 DOI: http://dx.doi.org/10.3126/njst.v14i1.8926
Characterization of geopolymers prepared using powdered brick
Journal of Materials Research and Technology, 2019
Geopolymerization of waste products can contribute to the solution of current environmental issues related to depletion of natural resources. In this paper, several geopolymer mixes are prepared using waste brick in powdered form, while different alkaline activators and curing conditions are applied. Experimental results show that the reaction rate at early age decreases with the increasing silicate modulus as well as with the rise of curing temperature; the reaction is though significantly slower than, e.g., for metakaolin-based geopolymers because of the low content of amorphous phase in the brick. The most compact microstructure is observed for geopolymers with highest reaction rate at early age; with increasing silicate modulus of the activator and decreasing curing temperature the compactness gradually decreases and the specific pore volume increases. Thermal analysis shows a decreasing weight loss with increasing silicate modulus for all temperatures, while dehydration of N-AS -H and C-AS -H gels are identified as the most important factors. Dehydroxylation of muscovite is found for the mixtures cured at temperatures up to 60 • C only, and decomposition of calcium carbonate just for 20 • C curing. Most crystalline phases detected by X-ray diffraction analysis in designed geopolymers are identical to those found in the raw precursor, which indicates only a partial geopolymerization and presence of a significant amount of unreacted particles. For geopolymers cured at 60 • C and 80 • C, formation of zeolitic phases is observed. While sodalite and chabazite are found only in mixtures with higher reaction rate, gismondine appears in geopolymers with higher silicate modulus.
Experimental Investigation of Geopolymer Brick for Strength and Durability
Journal of emerging technologies and innovative research, 2021
The mixture of aluminosilicate material such as fly ash, silica fume with an alkaline solution such as sodium hydroxide & sodium silicate completes the geopolymerization process and forms an activated alkaline solution that has the binding property. This activated alkaline solution is mixed with white clay and produces the geopolymer brick. The various trial mixes are worked out with an AAS/FA ratio between 0.4 to 0.5, Na2SiO3/NaOH ratio between 2 to 3, and molarity of alkaline solution between 12M to 16M. The various trial mix bricks will be prepared and oven cured at 70°c ambient temperature. The brick is then analyzed for compressive strength and Durability tests. The maximum compressive strength is achieved up to 5.1 N/mm 2 & water absorption of 5% when it is heated at 70°c for 7 days. Microstructure Analysis tests such as X-Ray Diffraction Test (XRD) is carried out on material. The geopolymerization reaction resulting in a formation of new product with different microstructure.
Development of construction materials from the geopolymerization of red clay and coal fly ash
BIBECHANA
Red clay contains solid aluminosilicate has been shown to be reactive in the presence of an alkaline activator. The addition of coal fly ash and lime has shown improvements in their mechanical and physical properties of the geopolymer products. FTIR analysis and SEM images of the product have shown the formation of aluminosilicate gel in the geopolymeric product. The maximum compressive strength of the geopolymer products GP-RFL was achieved to be 15.92 N/mm2 having water absorption of 10.47 % and bulk density 2.81 g/cm3. These results indicated that geopolymer mortars made from red clay, coal fly ash and lime could be used as an alternative construction material./p> BIBECHANA 19 (2022) 119-126