Rajiv Gupta; Ayub Ahmed; Sasidhar Kumar Reddy Ithepalli
Abstract
Large quantities of ash are generated every year by the various manufacturing industries as a waste by-product. This study aims to utilize waste by-product in concrete and to reduce its cost by replacing cement in parts with bottom ash. This research presents the results of the experimental investigations ...
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Large quantities of ash are generated every year by the various manufacturing industries as a waste by-product. This study aims to utilize waste by-product in concrete and to reduce its cost by replacing cement in parts with bottom ash. This research presents the results of the experimental investigations to study the use of bottom ash as partial replacement for cement in concrete and masonry units. Bottom ash is the coarser material, which falls into furnace bottom and constitutes about 20% of total ash content. The strength development for various percentage replacements (5-15%) of cement with bottom ash has been compared to control specimens of concrete and masonry.
Alena Sicakova; Viola Hospodarova; Nadezda Stevulova; Vojtech Vaclavik; Tomas Dvorsky
Abstract
In this paper, the experimental work providing the testing of cement mixture containing two types of cellulosic fibers, namely fibers from bleached wood pulp and recycled waste paper fibers, is given. Fibers are described by selected characteristics such as length, density, and pH. They were applied ...
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In this paper, the experimental work providing the testing of cement mixture containing two types of cellulosic fibers, namely fibers from bleached wood pulp and recycled waste paper fibers, is given. Fibers are described by selected characteristics such as length, density, and pH. They were applied as additive to the cement composite/plaster while they were dosed in different amounts: 0.2 %, 0.3 % and 0.5 % of the weight of both the filler and binder. Mixtures without fibers were prepared as reference samples. Density, water absorption, thermal conductivity, flexural and compressive strength were studied following by analyses of differences between resulting values. The observed differences in the physical, mechanical and thermal properties were found to be influenced by the properties (such as type, amount and other characteristics) of cellulosic fibers.
Rajeev Kuma; Saroj Kumari;S. Das; D.P. Mondal; Shyam Birla; Amit Vishwakarma; Anisha Chaudhary
Abstract
In the present investigation, influence of micronsize cenosphere particles derived from fly ash on the properties of aluminum composites was investigated. Aluminum-cenosphere (AC) composite was fabricated by modified stir casting technique. The mechanical and electromagnetic interference (EMI) shielding ...
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In the present investigation, influence of micronsize cenosphere particles derived from fly ash on the properties of aluminum composites was investigated. Aluminum-cenosphere (AC) composite was fabricated by modified stir casting technique. The mechanical and electromagnetic interference (EMI) shielding properties of AC composites were investigated. The obtained composites with cenosphere (+100 µm) loading demonstrate the excellent compressive strength of 251.3 MPa. This enhancement is due to the smaller size of cenosphere size provides the finer surface of the cenosphere. The addition of cenosphere in aluminum matrix improved dielectric and microwave absorption properties of composites in X band frequency region (8.2-12.4 GHz). The AC composites possess good EMI shielding effectiveness of -32.7 to -44.3 dB with 30% loading of cenosphere with various sizes (+212, +150 and +100 µm). The incorporation of lower size cenosphere (+100µm) in aluminum matrix significantly increases the interfacial polarization which leads to a higher absorption EMI shielding effectiveness (SE) of -31.1 dB at 2.0 mm thickness. This technique is very simple, economical and highly reproducible, which may facilitate the commercialization of such composite and it can be used as microwave absorbing materials in defense and aerospace applications.
Aldo G. P
Abstract
The effect of gamma-irradiated SiO2 nanoparticles on microstructure and mechanical properties of concrete was studied. SiO2 nanoparticles were irradiated at different irradiation doses (10, 50, 100 and 150 kGy) and then analyzed by transmission electron microscopy, Fourier-transform infrared and Raman ...
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The effect of gamma-irradiated SiO2 nanoparticles on microstructure and mechanical properties of concrete was studied. SiO2 nanoparticles were irradiated at different irradiation doses (10, 50, 100 and 150 kGy) and then analyzed by transmission electron microscopy, Fourier-transform infrared and Raman spectroscopies. Such ionizing treatment allowed improving the physical interactions between the nanoparticles and the cementitious matrix. Compressive strength and dynamical modulus of elasticity on concrete samples were determined. The results show significant improvements on these mechanical features when irradiated SiO2 nanoparticles were added; having up to 127 % of improvement for compressive strength and a 24 % for elasticity modulus when comparing to non-irradiated nanoparticles-reinforced concrete. Such improvements are related to the microstructural changes of concrete analyzed by Infrared spectroscopy and observed by scanning electron microscopy. Research shows important advances in the development and understanding of microstructure for nanoreinforced concrete with irradiated SiO2 nanoparticles.
Noor Md. Sadiqul Hasan; Habibur Rahman Sobuz; Abubakar Sharif Auwalu; Nafisa Tamanna
Abstract
This paper investigates of an experimental research that was conducted to study the effect of natural kenaf fiber on concrete production which implements in the sustainable construction industry as a low-cost material. Concrete produced with kenaf fiber reinforced concrete (KFRC) with fiber volume contents ...
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This paper investigates of an experimental research that was conducted to study the effect of natural kenaf fiber on concrete production which implements in the sustainable construction industry as a low-cost material. Concrete produced with kenaf fiber reinforced concrete (KFRC) with fiber volume contents are increasing 0%, 1%, 3% and 5% in the mix proportions. The concrete fresh properties consisting slump and density are determined in the laboratory. The compressive strength, compacting factor test, modulus of rupture, surface strength, and direct shear test of KFRC specimens are investigated and compared to the properties of conventional concrete specimens. A total number of 36 concrete cubes with the size of 150 mm x 150 mm x 150 mm were tested for compressive strength, 36 Concrete beams with the size of 100 mm x 100 mm x 350 mm were tested for flexural strength, and also 36 concrete small beams with the size of 100 mm x 100 mm x 350 mm were tested for direct shear test. All of the specimens were cured for 7, 14 and 28 days before testing. The experimental results indicate that the mechanical and fresh properties of KFRC are decreased then the conventional concrete specimens with the increased of kenaf fiber content. It is also observed that the additions of fiber decreased the ultimate load of the concrete for compressive strength, modulus of rupture and direct shear test. However, kenaf fiber concrete enhanced more toughness and ductility behaviour compared with the conventional concrete. Finally, it concluded that kenaf fiber is a suitable material that could potentially be used to produce low-cost ‘green’ concrete which has higher toughness and reduce the cracking propagation in the concrete structural applications.
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