Frontiers of Structural and Civil Engineering, 2017
The nanoparticles of SiO 2 were used in cement systems to modify the rheological behavior, to enh... more The nanoparticles of SiO 2 were used in cement systems to modify the rheological behavior, to enhance the reactivity of supplementary cementitious materials, and also to improve the strength and durability. In this research, low-cost nano-SiO 2 particles from natural hydrothermal solutions obtained by membrane ultrafiltration and, optionally, by cryochemical vacuum sublimation drying, were evaluated in portland cement based systems. The SiO 2-rich solutions were obtained from the wells of Mutnovsky geothermal power station (Far East of Russia). The constant nano-SiO 2 dosage of 0.25% (as a solid material by weight of cementitious materials) was used to compare the cement systems with different nanoparticles against a reference mortar and a commercially available nano-SiO 2. Nanoparticles were characterized by X-Ray Diffraction (XRD), BET Surface Area, Scanning Electron Microscope (SEM) and Fourier Transform Infrared (FTIR) spectroscopy techniques. It was demonstrated that the addition of polycarboxylate ether superplasticizer and the dispersion treatment using an ultrasound processor can be used to facilitate the distribution of nano-SiO 2 particles in the mixing water. The effect of nano-SiO 2 particles in portland cement mortars was investigated by evaluating the flow, heat of hydration and compressive strength development. It was demonstrated that the use of nano-SiO 2 particles can reduce the segregation and improve strength properties.
Processes occurring at the nanoscale ultimately affect the engineering properties and long-term p... more Processes occurring at the nanoscale ultimately affect the engineering properties and long-term performance of concrete. Concrete can be nano-engineered by incorporating nano-sized objects to control material behavior and add novel properties, or by grafting molecules onto cement particles, cement phases, aggregates, and additives to provide surface functionality. The nanoparticle is the elementary building block in nano-materials and is comprised of cluster of atoms with a size of 1-100 nm. Nanoparticles have been used to enhance the mechanical performance of materials, including metals, polymers, ceramic, and concrete composites. Nanosilica (nanoparticles of silicon dioxide, nano-SiO 2 ) is effective admixture improving the workability and strength of high-performance and self-compacting concrete. This article reviews the beneficial effects of the nanoparticles on the improvement of concrete performance.
The term ''icephobicity'' has emerged in the literature recently. An extensive discussion took pl... more The term ''icephobicity'' has emerged in the literature recently. An extensive discussion took place on whether the icephobicity is related to the superhydrophobicity, and the consensus is that there is no direct correlation. Besides the parallel between the icephobicity and superhydrophobicity for water/ice repellency, there are similarities on other levels including the hydrophobic effect/hydrophobic interactions, mechanisms of protein folding and ice crystal formation. In this paper, we report how ice adhesion is different from water using force balance analysis, and why superhydrophobic surfaces are not necessary icephobic. We also present experimental data on anti-icing of various surfaces and suggest a definition of icephobicity, which is broad enough to cover a variety of situations relevant to de-icing including low adhesion strength and delayed ice crystallization and bouncing.
ABSTRACT The addition of carbon nano-fibers (CNF) to fiber reinforced composites (FRC) based on p... more ABSTRACT The addition of carbon nano-fibers (CNF) to fiber reinforced composites (FRC) based on polyvinyl alcohol fibers can improve the flexural strength of composites. Depending on applied stress, moisture content, and exposure to chloride solutions, the developed CNF composites exhibit specific levels of electrical conductivity. Reported research has demonstrated a strong dependency of electrical response of composite to crack formation in moist and NaCl environments. It was demonstrated that the sensitivity to strain and chloride solution can be enhanced by CNF. The developed technology and smart composite material are scalable for application in nondestructive monitoring of concrete structures that require improved integrity under service loads and stability in harsh environments.
The reported research examined the effect of 5-70 nm SiO 2 nanoparticles on the mechanical proper... more The reported research examined the effect of 5-70 nm SiO 2 nanoparticles on the mechanical properties of nano-cement materials. The strength development of portland cement with nano-SiO 2 and superplasticizing admixture was investigated. Experimental results demonstrate an increase in the compressive and flexural strength of mortars with developed nanoparticles. The distribution of nano-SiO 2 particles within the cement paste plays an essential role and governs the overall performance of these products. Therefore, the addition of a superplasticizer was proposed to facilitate the distribution of nano-SiO 2 particles. Superplasticized mortars with 0.25% of selected nano-SiO 2 demonstrated a 16% increase of 1-day compressive strength, reaching 63.9 MPa; the 28-day strength of these mortars was 95.9 MPa (vs. strength of reference superplasticized mortars of 92.1 MPa). Increase of 28-day flexural strength of superplasticized mortars with selected nano-SiO 2 was 18%, reaching 27.1 MPa. It is concluded that the effective dispersion of nanoparticles is essential to obtain composite materials with improved performance.
The reported research examines the effect of 5-70 nm SiO 2 nanoparticles on the mechanical proper... more The reported research examines the effect of 5-70 nm SiO 2 nanoparticles on the mechanical properties of nanocement materials. The strength development of portland cement with nano-SiO 2 and superplasticizing admixture is investigated. Experimental results demonstrate an increase in the compressive strength of mortars with SiO 2 nanoparticles. The distribution of nano-SiO 2 particles within the cement paste plays an essential role and governs the overall performance of these products. Therefore, the addition of a superplasticizer is proposed to facilitate the distribution of nano-SiO 2 particles. The application of effective superplasticizer and high-speed dispergation are found to be very effective dispersion techniques that improve the strength of superplasticized portland cement mortars, reaching up to 63.9 MPa and 95.9 MPa after aging during 1 and 28 days, respectively. These values compare favorably with the observed compressive strengths of reference portland cement mortars of 53.3 MPa and 86.1 MPa. It is concluded that the effective dispersion of nanoparticles is essential to obtain the composite materials with improved performance.
Kaolin, one of the materials of major importance for the ceramic and paper industry, is also used... more Kaolin, one of the materials of major importance for the ceramic and paper industry, is also used in the construction industry as a raw material for the production of white cement clinker and, in the form of metakaolin, as an artificial pozzolanic additive for concrete. Metakaolin is a ...
This paper describes the exploration of a sensor concept for use in structural health monitoring.... more This paper describes the exploration of a sensor concept for use in structural health monitoring. The sensor is based on the principle of electromagnetic (EM) surface wave propagation, and consists of a thin-layer of wave-guiding media attached to a metal base (e.g., steel bridge elements) and an EM wave emitter and receiver. Targeting at a low-cost and practical solution, various dielectric materials that facilitate EM wave propagation were examined. Low-density polyethylene was determined to have the most suitable dielectric properties and was selected for laboratory tests using tension coupon specimens.
Turkey has a long tradition (starting from the prehistoric civilizations) and experience in explo... more Turkey has a long tradition (starting from the prehistoric civilizations) and experience in exploring and processing clay raw materials into ceramic products. Many of these products, such as tiles and sanitary ware, are manufactured for domestic and export markets. Kaolin clay is one of the raw materials of major importance for the ceramic and paper industry, as well as for a number of auxiliary applications. There is an ongoing interest to apply kaolin clay in the construction industry as a raw material for the production of white cement clinker and as an artificial pozzolanic additive for concrete (in a form of metakaolin). This report presents the results related to search, assessment and evaluation of available resources for advanced cement and concrete additives.
Granulated blast furnace slag (GBFS) cement, containing up to 60% slag, is sometimes used in repa... more Granulated blast furnace slag (GBFS) cement, containing up to 60% slag, is sometimes used in repair materials applied at intermediate temperatures of 150-300 8C. Low rate of strength development, especially at early ages, is considered a common disadvantage of repair mortars based on slag cement. The present research was oriented to improving a GBFS-portland cement binder for application as a repair material in the chemical industry when high thermal or acid resistance is required. It was found that the enhancement of GBFS-portland cement-based materials can be achieved with the help of silica fume (SF) and a superplasticizer (SP). The effect of different SPs on the compressive and flexural strength of SF-blast furnace slag-portland cement mortars was investigated. These mortars, in addition to high strength, demonstrate high thermal and acid resistance. D
Contemporary requirements for gypsum-based composite materials (GBCM) for rendering or plastering... more Contemporary requirements for gypsum-based composite materials (GBCM) for rendering or plastering include controlled setting time, good workability, sag resistance, high compressive and flexural strength, perfect bond to concrete or brick, water resistance, and improved heat and noise insulation. The application of a number of chemical admixtures and mineral additives was found to be necessary to provide the required performance for
... 1 THE MODELING OF DENSE PACKING OF AGGREGATES AS AN APPROACH TO OPTIMIZING THE PROPORTIONING ... more ... 1 THE MODELING OF DENSE PACKING OF AGGREGATES AS AN APPROACH TO OPTIMIZING THE PROPORTIONING OF CONCRETE MIXTURES KONSTANTIN SOBOLEV Professor of Civil Engineering, Universidad Autónoma de Nuevo León Monterrey, NL, México ...
... Authors express their grati-tude to Ipek S¸ener and Bahadir Erdogan for their help with prepa... more ... Authors express their grati-tude to Ipek S¸ener and Bahadir Erdogan for their help with preparation of the samples. ... Tomris Ertün, Asim Yeg˘inobali and Pelin Turker are research staff members of the Cement and Concrete Research Institute of TCMA, Turkey. ...
Frontiers of Structural and Civil Engineering, 2017
The nanoparticles of SiO 2 were used in cement systems to modify the rheological behavior, to enh... more The nanoparticles of SiO 2 were used in cement systems to modify the rheological behavior, to enhance the reactivity of supplementary cementitious materials, and also to improve the strength and durability. In this research, low-cost nano-SiO 2 particles from natural hydrothermal solutions obtained by membrane ultrafiltration and, optionally, by cryochemical vacuum sublimation drying, were evaluated in portland cement based systems. The SiO 2-rich solutions were obtained from the wells of Mutnovsky geothermal power station (Far East of Russia). The constant nano-SiO 2 dosage of 0.25% (as a solid material by weight of cementitious materials) was used to compare the cement systems with different nanoparticles against a reference mortar and a commercially available nano-SiO 2. Nanoparticles were characterized by X-Ray Diffraction (XRD), BET Surface Area, Scanning Electron Microscope (SEM) and Fourier Transform Infrared (FTIR) spectroscopy techniques. It was demonstrated that the addition of polycarboxylate ether superplasticizer and the dispersion treatment using an ultrasound processor can be used to facilitate the distribution of nano-SiO 2 particles in the mixing water. The effect of nano-SiO 2 particles in portland cement mortars was investigated by evaluating the flow, heat of hydration and compressive strength development. It was demonstrated that the use of nano-SiO 2 particles can reduce the segregation and improve strength properties.
Processes occurring at the nanoscale ultimately affect the engineering properties and long-term p... more Processes occurring at the nanoscale ultimately affect the engineering properties and long-term performance of concrete. Concrete can be nano-engineered by incorporating nano-sized objects to control material behavior and add novel properties, or by grafting molecules onto cement particles, cement phases, aggregates, and additives to provide surface functionality. The nanoparticle is the elementary building block in nano-materials and is comprised of cluster of atoms with a size of 1-100 nm. Nanoparticles have been used to enhance the mechanical performance of materials, including metals, polymers, ceramic, and concrete composites. Nanosilica (nanoparticles of silicon dioxide, nano-SiO 2 ) is effective admixture improving the workability and strength of high-performance and self-compacting concrete. This article reviews the beneficial effects of the nanoparticles on the improvement of concrete performance.
The term ''icephobicity'' has emerged in the literature recently. An extensive discussion took pl... more The term ''icephobicity'' has emerged in the literature recently. An extensive discussion took place on whether the icephobicity is related to the superhydrophobicity, and the consensus is that there is no direct correlation. Besides the parallel between the icephobicity and superhydrophobicity for water/ice repellency, there are similarities on other levels including the hydrophobic effect/hydrophobic interactions, mechanisms of protein folding and ice crystal formation. In this paper, we report how ice adhesion is different from water using force balance analysis, and why superhydrophobic surfaces are not necessary icephobic. We also present experimental data on anti-icing of various surfaces and suggest a definition of icephobicity, which is broad enough to cover a variety of situations relevant to de-icing including low adhesion strength and delayed ice crystallization and bouncing.
ABSTRACT The addition of carbon nano-fibers (CNF) to fiber reinforced composites (FRC) based on p... more ABSTRACT The addition of carbon nano-fibers (CNF) to fiber reinforced composites (FRC) based on polyvinyl alcohol fibers can improve the flexural strength of composites. Depending on applied stress, moisture content, and exposure to chloride solutions, the developed CNF composites exhibit specific levels of electrical conductivity. Reported research has demonstrated a strong dependency of electrical response of composite to crack formation in moist and NaCl environments. It was demonstrated that the sensitivity to strain and chloride solution can be enhanced by CNF. The developed technology and smart composite material are scalable for application in nondestructive monitoring of concrete structures that require improved integrity under service loads and stability in harsh environments.
The reported research examined the effect of 5-70 nm SiO 2 nanoparticles on the mechanical proper... more The reported research examined the effect of 5-70 nm SiO 2 nanoparticles on the mechanical properties of nano-cement materials. The strength development of portland cement with nano-SiO 2 and superplasticizing admixture was investigated. Experimental results demonstrate an increase in the compressive and flexural strength of mortars with developed nanoparticles. The distribution of nano-SiO 2 particles within the cement paste plays an essential role and governs the overall performance of these products. Therefore, the addition of a superplasticizer was proposed to facilitate the distribution of nano-SiO 2 particles. Superplasticized mortars with 0.25% of selected nano-SiO 2 demonstrated a 16% increase of 1-day compressive strength, reaching 63.9 MPa; the 28-day strength of these mortars was 95.9 MPa (vs. strength of reference superplasticized mortars of 92.1 MPa). Increase of 28-day flexural strength of superplasticized mortars with selected nano-SiO 2 was 18%, reaching 27.1 MPa. It is concluded that the effective dispersion of nanoparticles is essential to obtain composite materials with improved performance.
The reported research examines the effect of 5-70 nm SiO 2 nanoparticles on the mechanical proper... more The reported research examines the effect of 5-70 nm SiO 2 nanoparticles on the mechanical properties of nanocement materials. The strength development of portland cement with nano-SiO 2 and superplasticizing admixture is investigated. Experimental results demonstrate an increase in the compressive strength of mortars with SiO 2 nanoparticles. The distribution of nano-SiO 2 particles within the cement paste plays an essential role and governs the overall performance of these products. Therefore, the addition of a superplasticizer is proposed to facilitate the distribution of nano-SiO 2 particles. The application of effective superplasticizer and high-speed dispergation are found to be very effective dispersion techniques that improve the strength of superplasticized portland cement mortars, reaching up to 63.9 MPa and 95.9 MPa after aging during 1 and 28 days, respectively. These values compare favorably with the observed compressive strengths of reference portland cement mortars of 53.3 MPa and 86.1 MPa. It is concluded that the effective dispersion of nanoparticles is essential to obtain the composite materials with improved performance.
Kaolin, one of the materials of major importance for the ceramic and paper industry, is also used... more Kaolin, one of the materials of major importance for the ceramic and paper industry, is also used in the construction industry as a raw material for the production of white cement clinker and, in the form of metakaolin, as an artificial pozzolanic additive for concrete. Metakaolin is a ...
This paper describes the exploration of a sensor concept for use in structural health monitoring.... more This paper describes the exploration of a sensor concept for use in structural health monitoring. The sensor is based on the principle of electromagnetic (EM) surface wave propagation, and consists of a thin-layer of wave-guiding media attached to a metal base (e.g., steel bridge elements) and an EM wave emitter and receiver. Targeting at a low-cost and practical solution, various dielectric materials that facilitate EM wave propagation were examined. Low-density polyethylene was determined to have the most suitable dielectric properties and was selected for laboratory tests using tension coupon specimens.
Turkey has a long tradition (starting from the prehistoric civilizations) and experience in explo... more Turkey has a long tradition (starting from the prehistoric civilizations) and experience in exploring and processing clay raw materials into ceramic products. Many of these products, such as tiles and sanitary ware, are manufactured for domestic and export markets. Kaolin clay is one of the raw materials of major importance for the ceramic and paper industry, as well as for a number of auxiliary applications. There is an ongoing interest to apply kaolin clay in the construction industry as a raw material for the production of white cement clinker and as an artificial pozzolanic additive for concrete (in a form of metakaolin). This report presents the results related to search, assessment and evaluation of available resources for advanced cement and concrete additives.
Granulated blast furnace slag (GBFS) cement, containing up to 60% slag, is sometimes used in repa... more Granulated blast furnace slag (GBFS) cement, containing up to 60% slag, is sometimes used in repair materials applied at intermediate temperatures of 150-300 8C. Low rate of strength development, especially at early ages, is considered a common disadvantage of repair mortars based on slag cement. The present research was oriented to improving a GBFS-portland cement binder for application as a repair material in the chemical industry when high thermal or acid resistance is required. It was found that the enhancement of GBFS-portland cement-based materials can be achieved with the help of silica fume (SF) and a superplasticizer (SP). The effect of different SPs on the compressive and flexural strength of SF-blast furnace slag-portland cement mortars was investigated. These mortars, in addition to high strength, demonstrate high thermal and acid resistance. D
Contemporary requirements for gypsum-based composite materials (GBCM) for rendering or plastering... more Contemporary requirements for gypsum-based composite materials (GBCM) for rendering or plastering include controlled setting time, good workability, sag resistance, high compressive and flexural strength, perfect bond to concrete or brick, water resistance, and improved heat and noise insulation. The application of a number of chemical admixtures and mineral additives was found to be necessary to provide the required performance for
... 1 THE MODELING OF DENSE PACKING OF AGGREGATES AS AN APPROACH TO OPTIMIZING THE PROPORTIONING ... more ... 1 THE MODELING OF DENSE PACKING OF AGGREGATES AS AN APPROACH TO OPTIMIZING THE PROPORTIONING OF CONCRETE MIXTURES KONSTANTIN SOBOLEV Professor of Civil Engineering, Universidad Autónoma de Nuevo León Monterrey, NL, México ...
... Authors express their grati-tude to Ipek S¸ener and Bahadir Erdogan for their help with prepa... more ... Authors express their grati-tude to Ipek S¸ener and Bahadir Erdogan for their help with preparation of the samples. ... Tomris Ertün, Asim Yeg˘inobali and Pelin Turker are research staff members of the Cement and Concrete Research Institute of TCMA, Turkey. ...
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