دانلود رایگان مقاله لاتین اثر خاکستر بادی بر خواص ملات از سایت الزویر
عنوان فارسی مقاله:
اثر خاکستر بادی و عامل درجه بندی بر خواص ملات با استفاده از از روش شناسی سطح پاسخ
عنوان انگلیسی مقاله:
Effect of fly ash and grading agent on the properties of mortar using response surface methodology
سال انتشار : 2017
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مقدمه انگلیسی مقاله:
1. Introduction
The manufacturing of cement accounts for ~5% of the total anthropogenic release of CO2 to the atmosphere [31,9]. In an effort to reduce anthropogenic CO2 emission and for the economic reasons as reducing the clinker grinding energy, the grinding agent has been commonly used to partly replace the Portland cement in concrete and to improve its properties [5]. Equally important to mention is that addition of the grinding agent in Portland cement has generally shown improvement of the workability of the fresh concrete [2], the mechanical strength and durability of the hardened concrete [15,37]. However, as commonly reported, the grinding agent increases the rate of strength development and it also reduces the appearance of cracks and minor deterioration [26,8]. Cement is a widely used construction material worldwide. The raw materials are easily available and it does not require complex or expensive equipment to create. But due to its popularity and demand as a construction material, some of its component should have an alternative source. In this context, fly ash (FA) and grinding agent have been commonly used to partly replace the Portland cement in concrete. Fly ash is a by product waste material of thermal power plants. The manufacturers of these days use this waste as substitute to various construction materials and it is sold at a low cost. Pozzolanic reaction by fly ash (FA) with the formed Ca(OH)2 produces additional C–S–H gel. Therefore, the curing period should be prolonged for FA-cement concretes due to a slower pozzolanic reaction, especially when a high volume of FA is used. For example, evidence of FA reaction, determined by Ca(OH)2 consumption, was noticed after 7 days of curing and a significant increase of compressive strength in FA-cement pastes was observed after 28 days [10]. Similarly, porefilling effect and pozzolanic reaction in FA cement concrete occurred after 28 days of curing and a significant contribution of fly ash addition to the strength was noticed after 90 days of curing [7]. Due to its increasing demand, it is not easy to find the fly ash available in market, which presents a serious problem. In addition, another solution is applied, the use of grinding agent (GA) which presents a revolution in the cement industry. It is known that this grinding agent is used to facilitate the grinding of the Portland clinker and to improve the cement physicochemical properties. This GA adsorbed on the surface of the material to be comminuted, i.e. either on the exterior surfaces or on the microcrack walls where it manages to enter. An immediate effect is a decrease in hardness accompanied by phenomena of adhesion and clogging [39]. Also, this cement addition gets adsorbed on the surface of the material undergoing grinding and reduces the surface energy, which only leads to further breakage and it facilitates the grinding of the clinker (The Rebinder effect) [30–36]. Inaddition, the effect of this agent on the improvement of cement quality is presented by the formation of a dense film between the cement grains, during the cement hydration, which develops the physicochemical properties of the cement. Due to the high importance and efficiency of these products, the aim of this research wasto assess significance of curing period for the development of compressive strength of the cement pastes containing fly ash and grinding agent as admixtures. To this end, a global optimization of the mixture was made to find the mix design possessing the minimum of cement grinding time and the maximum achievable compressive strength of the hardened pastes cured for 7, 28 and 90 days.
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کلمات کلیدی:
Significance of Tests and Properties of Concrete and Concrete-making ... https://books.google.com/books?isbn=0803133677 Joseph F. Lamond, J. H. Pielert - 2006 - Technology & Engineering Klieger and Gebler [56] called attention to the effect of certain fly ashes in reducing ... of an air-entraining agent to an aqueous slurry of fly ash until a stable foam is ... calls for using a reagent-grade surfactant and including cement in the fly ash ... [PDF]effects of fly ash and desulphogypsum - CiteSeerX citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.633.4352&rep=rep1... by ALİÖ BAYTAR - 2005 - Cited by 2 - Related articles the presence of a bonding or cementing agent, is allowed to free access to additional ..... geotechnical properties of collapsible soils treated with Çayırhan fly ash and .... grade of the building site or using some basements are the methods for ... Properties of pervious concrete containing fly ash: Road Materials and ... www.tandfonline.com/doi/full/10.1080/14680629.2011.651834?src=recsys Mar 26, 2012 - Hence, environmentally friendly pervious concrete with fly ash can be .... effects of aggregate type and aggregate grading on the properties of ... [PDF]Research Journal of Pharmaceutical, Biological and ... - RJPBCS www.rjpbcs.com/pdf/2016_7(5)/[251].pdf Optimization the Effect of Fly Ash and Grading Agent on the Physicochemical and Mechanical Properties of Portland Cement. N. Mtarfi1*, Z. Rais1, M. Taleb1, ... Fly ash - Wikipedia https://en.wikipedia.org/wiki/Fly_ash Fly ash, also known as "pulverised fuel ash" in the United Kingdom, is a coal combustion .... The chemical properties of the fly ash are largely influenced by the chemical content of the coal ... Possessing pozzolanic properties, the glassy silica and alumina of Class F fly ash requires a cementing agent, such as Portland ... Coal Fly Ash - User Guideline - Portland Cement Concrete - User ... https://www.fhwa.dot.gov/publications/research/infrastructure/structures/.../cfa53.cfm Coal fly ash has been successfully used in Portland cement concrete (PCC) as a mineral ... Class C fly ash has self-cementing properties as well as pozzolanic properties. .... by LOI) higher than 3 to 4 percent have an adverse effect on air entrainment. .... Certain fly ashes will reduce the effectiveness of air entraining agents, ... Searches related to Effect of fly ash and grading agent on the properties what does fly ash do in concrete fly ash concrete disadvantage properties of fly ash pdf fly ash concrete pdf fly ash cement ratio fly ash concrete problems fly ash concrete mix design fly ash concrete strength
