321 research outputs found

    Geopolymer coating paste on concrete for photocatalytic performance

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    Construction materials mainly used Portland cement as raw materials mainly caused global warming effect around the world. This article report a review on a research work carried out on the use of geopolymer coating on the concrete surface with catalyst for a good adsorption and efficiency via photocatalytic activity using sunlight. The geopolymer paste deposited by coating on the concrete or other building construction surface. The geopolymer paste were prepared by mixing aluminosilicates material with alkaline activator added with catalyst materials such as titanium dioxide and zinc oxide. The performance of geopolymer coating in removal of dyes reported comparable with other materials. Photocatalytic activity performance evaluate by adsorption of dyes onto geopolymer

    Feasibility study on utilization of palm fibre waste into fired clay brick

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    Malaysia is the second largest of palm oil producer after Indonesia, which contribute to 50 % of palm oil production. With this demand, the increasing of palm oil plantation over the years has led to the large production of agricultural waste, for example palm fibre waste. This study investigates different percentages of palm fibre (0 %, 1 %, 5 % and 10 %) to be incorporated into fired clay brick. Manufactured bricks were fired at 1 Ā°C/min heating rate up to 1050 Ā°C. The effects of manufacture bricks on the physical and mechanical properties of manufactured brick were also determined. All brick samples were tested due to the physical and mechanical properties which include dry density, firing shrinkage, initial rate of suction (IRS), water absorption, porosity and compressive strength. Findings show that increasing palm fibre waste affected the properties of brick, which decreased their density, besides increased firing shrinkage, IRS, water absorption, porosity and compressive strength. However, all the manufactured brick still followed the requirement

    Interpreting Analysis on Rhetorical Strategies Modeling in Computer Science Research Articles

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    Description on rhetorical strategies modeling proposed by experts in the field of language provides clues on strategies used in research writing. However, the interpretation and analysis on the utilization of the rhetorical strategies models are limited to comparing the strategies used in articles grouped according to research disciplines such as biomedical, linguistics, and arts. In view of the constraint, this chapter focuses on the interpretations of rhetorical strategies modeling by analyzing the computer science research articles in a few categories. The first interpretation of analysis is on the articles with high and low citation index, followed by analysis on the articles grouped according to journal wise population and lastly analysis on articles written by non-native writers. The interpretation of the analysis suggested that the strategies proposed in the models are used differently by the writers of articles with high and low citations, writers of different journals, and non-native writers. The descriptions provided in this chapter account on the important strategies utilized by highly cited writers, specific journals, and non-native writers

    Clay-Based Materials in Geopolymer Technology

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    The term ā€œgeopolymerā€ was introduced by Davidovits in the 1970s. The prefix ā€œgeoā€ was selected to symbolize the constitutive relationship of the binders to geological materials, natural stone and/or minerals. Geopolymer is mineral polymers of inorganic polymer glasses with structure resembling natural zeolitic materials. Previously, geopolymer formation used source materials such as clay (e.g. kaolin and calcined kaolin) or industrial by-product (e.g. slag and fly ash). The precursor material plays an important role in the formation of geopolymer. The source material provides silicon (Si) and aluminum (Al) for reaction by an alkali activator solution. The Si and Al contents in the source materials dissolve in the alkaline activator solution and then polymerize to form a polymeric Si-O-Al-O framework which becomes the binder. Geopolymeric materials are attractive because of their excellent mechanical properties; durability and thermal stability can also be achieved. Owing to their low calcium content, they are more resistant to acid attack than materials based on Portland cement. In addition, they are of great interest because of the reduced energy requirement for their manufacture and the higher sustainability. Recently the search for alternative low cost and easily available materials led among others to Clay. Clay generally consists of a mixture of different clay minerals and associated minerals, which are strongly affected by the nature of the parent rocks. These materials are extensively distributed over the surface of the world and may show certain reactivity after a thermal activation process shows a great potential to be utilized in geopolymer technology. This article presents the potential of different types of clay as the source materials for geopolymerization reaction in terms of morphological properties. Moreover, the mechanical and microstructural properties of geopolymer made with various kinds of clay and its potential application are also presented

    Chapter Fly Ash as a Cementitious Material for Concrete

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    This paper presents a review on fly ash as prime materials used for geopolymer. Due to its advantages of abundant resources, less in cost, great workability and high physical properties, fly ash leads to achieving high mechanical properties. Fly ash is considered as one of the largest generated industrial solid wastes or so-called industrial by-products, around the world particularly in China, India, and USA. The characteristics of fly ash allow it to be a geotechnical material to produce geopolymer cement or concrete as an alternative of ordinary Portland cement. Many efforts are made in this direction to formulate a suitable mix design of fly ash-based geopolymer by focusing on fly ash as the main prime material. The physical properties, chemical compositions, and chemical activation of fly ash are analyzed and evaluated in this review paper. Reference has been made to different ASTM, ACI standards, and other researches work in geopolymer area

    Axial vibration mode of coupled liquid-structure-gas system in a rigid cylindrical container

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    This paper describes the axial vibration analysis of a closed ends rigid cylindrical container containing liquid and gas which separated by a thin circular plate at their interface. The liquid depths inside the container were varied and then the mode of vibration and the natural frequencies were analyzed. The natural frequencies obtained experimentally were compared favorably with those of commercial finite element analysis software, ANSYS. The vibration mode of the liquid-structure interaction of the tank system can be visualized from the software post processing animation/plot. The visualized modes are also consistent with the measurement by the respective experimental transducers. It was found that strong coupling predominantly occur between liquid and structure. In weak coupling conditions, the modes are predominantly gas mod

    Fly Ash as a Cementitious Material for Concrete

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    This paper presents a review on fly ash as prime materials used for geopolymer. Due to its advantages of abundant resources, less in cost, great workability and high physical properties, fly ash leads to achieving high mechanical properties. Fly ash is considered as one of the largest generated industrial solid wastes or so-called industrial by-products, around the world particularly in China, India, and USA.Ā The characteristics of fly ash allow it to be a geotechnical material to produce geopolymer cement or concrete as an alternative of ordinary Portland cement. Many efforts are made in this direction to formulate a suitable mix design of fly ash-based geopolymer by focusing on fly ash as the main prime material. The physical properties, chemical compositions, and chemical activation of fly ash are analyzed and evaluated in this review paper. Reference has been made to different ASTM, ACI standards, and other researches work in geopolymer area

    Utilization of bottom ash for alkali-activated (SI-AL) materials: a review

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    In Malaysia, 180 tons/day of solid waste bottom ash are produced by a Tanjung Bin power station, which is one of the four coal power plants in Malaysia. Hence, to overcome this problem, the solid waste could be used as source material in construction industry using geopolymer technique. Alkali-activated materials are introduced as an alternative materials to ordinary Portland cement (OPC) in the construction industry. There are many types of alkaline activator raw materi als such as bottom ash, fly ash, metakaolin and so on that can be substituted the materials existing such as cement and fine or course aggregate in the market now to make any production where the materials are coming from waste.The geopolymerization process involves a substantially fast chemical reaction under alkaline conditions with Si and Al minerals that results in a threeā€dimensional polymeric chain and ring structure consisting of Siā€Oā€Alā€O. The higher Siā€Oā€Alā€O bonds are contained in the geopolymer, the higher compressive strength results will find. Several types of building materials such as

    The Influence of Sodium Hydroxide Concentration on Physical Properties and Strength Development of High Calcium Fly Ash Based Geopolymer as Pavement Base Materials

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    This paper deals with the development of high calcium fly ash based geopolymers. Geopolymer paste was prepared from fly ash alkaline activator solutions using various mix design including molarity of sodium hydroxide used (6-14M) with solid-to-liquid ratio (1.0-3.0) and the sample were curing at ambient temperature. In this paper, flow value, setting time and unconfined compressive strength of high calcium fly ash based geopolymer paste was carried out using flow table equipment, Vicat's apparatus and compression testing machine to measure the properties caused by high calcium fly ash. It was found that solid to liquid ratio of 2.0 and NaOH molarity of 12M was the best mix design to be applied due to its maximum unconfined compressive strength achieved (up to 19MPa at 28 days) as well as its flow ability of the fresh paste which shown better result compared to other mix designs. High calcium was also found to result in higher strength
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