The Experts below are selected from a list of 8268 Experts worldwide ranked by ideXlab platform
S P Mehrotra - One of the best experts on this subject based on the ideXlab platform.
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mechanical activation of granulated blast furnace slag and its effect on the properties and structure of portland slag Cement
Cement & Concrete Composites, 2008Co-Authors: Sanjay Kumar, Aditya Bandopadhyay, T C Alex, Ravi B Kumar, Rakesh Kumar, S P MehrotraAbstract:Mechanically activated granulated blast furnace slag (GBFS) was used in the range of 50–95% to replace clinker in portland slag Cement (PSC). The slag and clinker were activated separately using an attrition mill and mixed to prepare Cement formulations. Use of activated slag resulted in a remarkable increase in strength vis-a-vis Commercial slag Cement. Both 1-day and 28-day strength were found to increase with an increase in slag content up to 70%. The strength of the sample containing 80–85% slag was comparable to the Commercial Cement used as a reference. It was observed that mechanical activation of slag was more critical from the point of view of strength development. The hydrated Cement samples were characterised using powder X-ray diffraction (XRD), scanning electron microscopy with X-ray microanalysis (SEM-EDS) and simultaneous thermogravimetry and differential thermal analysis (TG/DTA). It is established that microstructural changes resulting from enhanced reactivity of slag and densification are related with the improvement in Cement strength.
Pekka K Vallittu - One of the best experts on this subject based on the ideXlab platform.
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evaluation of resin adhesion to zirconia ceramic using some organosilanes
Dental Materials, 2006Co-Authors: J P Matinlinna, Mutlu Özcan, Lippo V J Lassila, Timo T Heikkinen, Pekka K VallittuAbstract:Abstract Objectives This study evaluated and compared the effect of three trialkoxysilane coupling agents on the bond strength of a Bis-GMA-based unfilled resin and a dimethacrylate-based resin composite luting Cement to a zirconia ceramics (Procera® AllZircon, Nobel Biocare, Goteborg, Sweden). Methods Six square-shaped zirconia specimens were used for each test group, a total of 72 specimens. The specimens in each group were all assigned to air-borne alumina particle abrasion followed by tribochemical silica-coating and silanization with 1 vol% solutions of 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, or 3-isocyanatopropyltriethoxysilane in an ethanol–water mixture. The sample stubs were made of a Bis-GMA/MMA/DMAEMA resin or a Commercial resin composite luting Cement (RelyX™ ARC, 3M ESPE, Seefeld, Germany). They were bonded to the conditioned and silanized silica-coated zirconia specimens using polyethylene molds. All specimens were tested at dry and thermo-cycled (6000, 5–55 °C, 30 s) conditions. The shear bond strength of resin stubs to zirconia was measured in a universal testing machine (cross-head speed 1 mm/min). Results In dry conditions, the highest shear bond strength was 9.7 MPa (S.D. 3.3 MPa), and for thermo-cycled samples 7.4 MPa (S.D. 2.4 MPa) was obtained with RelyX™ ARC Cement with 3-methacryloyloxypropyltrimethoxysilane. In general, thermo-cycling decreased the bond strengths significantly for the Bis-GMA resin (ANOVA, p Significance Bonding of the experimental resin and Commercial Cement to silica-coated zirconia is effective with 3-methacryloyloxypropyltrimethoxysilane or 3-methacryloyloxypropyltrimethoxysilane, but not with 3-isocyanatopropyltriethoxysilane.
Yixin Shao - One of the best experts on this subject based on the ideXlab platform.
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production of Cement free construction blocks from industry wastes
Journal of Cleaner Production, 2016Co-Authors: Mehrdad Mahoutian, Yixin ShaoAbstract:This study explores the possibility of making carbon-negative and Cement-free construction blocks using steel slag as sole binder and blast furnace slag as lightweight aggregates through carbonation activation. Both steel slag and blast furnace slag are by-products of steel making process. The goal of the study is to develop a clean production that can utilize slag and carbon dioxide to produce environment friendly construction products. Carbonation activation was implemented during the curing of the blocks to accelerate early strength gain. The physical and durability of slag-bond concrete blocks were examined through their density, water absorption, compressive strength and freeze and thaw resistance. An economic analysis was performed and a carbon balance was computed to evaluate the feasibility of making carbon-negative and economically-competitive slag-bond blocks. This study demonstrates that the proposed process consumes no natural resources, produces no wastes, is capable for carbon sequestration and is a clean production. The slag-bond concrete block is a carbon-negative product. In addition, slag-bond concrete block exhibited better mechanical and durability properties compared to the Commercial Cement block. The cost analysis suggests that slag-bond concrete blocks can be made at a lower cost compared to the Commercial Cement block if they are mass produced.
Rakhyun Kim - One of the best experts on this subject based on the ideXlab platform.
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Theoretical Study on the Production of Environment-Friendly Recycled Cement Using Inorganic Construction Wastes as Secondary Materials in South Korea
Sustainability, 2018Co-Authors: Sung Ho Tae, Rakhyun KimAbstract:The Cement industry endeavors to reduce CO2 emissions from Cement manufacturing by utilizing industrial by-products as alternative fuels and developing secondary concrete products from construction wastes. With these efforts, the Cement industry is attempting to become more eco-friendly and reduce environmental load. This study analyzed the possibility of using inorganic construction wastes to produce environmentally friendly recycled Cement using the process of proportioning. To this end, the types and production trends of recyclable construction wastes and previous studies on the development of recycled Cement using such construction wastes were analyzed. Based on this analysis, recyclable inorganic construction wastes were selected, and real waste was collected. The chemical composition of each inorganic construction waste was analyzed using X-ray fluorescence, and the composition of ordinary Commercial Cement was used as the baseline. After the collected inorganic construction wastes were mixed, they were fired using the Bogue formula. The mineral components of clinker, which was generated from the firing process, were predicted and analyzed. Waste gypsum board and ceiling materials were shown to contain large amounts of CaO, which could substitute limestone—a key component of Cement. These results suggested that if the limestone content was greater than 85 wt %, mixing inorganic construction wastes in appropriate proportions could be used to develop various types of Portland Cement.
Sanjay Kumar - One of the best experts on this subject based on the ideXlab platform.
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mechanical activation of granulated blast furnace slag and its effect on the properties and structure of portland slag Cement
Cement & Concrete Composites, 2008Co-Authors: Sanjay Kumar, Aditya Bandopadhyay, T C Alex, Ravi B Kumar, Rakesh Kumar, S P MehrotraAbstract:Mechanically activated granulated blast furnace slag (GBFS) was used in the range of 50–95% to replace clinker in portland slag Cement (PSC). The slag and clinker were activated separately using an attrition mill and mixed to prepare Cement formulations. Use of activated slag resulted in a remarkable increase in strength vis-a-vis Commercial slag Cement. Both 1-day and 28-day strength were found to increase with an increase in slag content up to 70%. The strength of the sample containing 80–85% slag was comparable to the Commercial Cement used as a reference. It was observed that mechanical activation of slag was more critical from the point of view of strength development. The hydrated Cement samples were characterised using powder X-ray diffraction (XRD), scanning electron microscopy with X-ray microanalysis (SEM-EDS) and simultaneous thermogravimetry and differential thermal analysis (TG/DTA). It is established that microstructural changes resulting from enhanced reactivity of slag and densification are related with the improvement in Cement strength.