Environment
U. N. Wilson; J. E. Sani; A. Yusuf; O. C. Eze
Abstract
This research work examined the effect of jute fibre on the shear strength of concrete. Fibre volume fractions of 0%, 0.25%, 0.5%, and 0.75% for grades 25, 30, 35 and 40 N/mm2 respectively were used. A total of 32 beams and 96 cubes were prepared. 16 beams and 48 cubes were cured at room temperature ...
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This research work examined the effect of jute fibre on the shear strength of concrete. Fibre volume fractions of 0%, 0.25%, 0.5%, and 0.75% for grades 25, 30, 35 and 40 N/mm2 respectively were used. A total of 32 beams and 96 cubes were prepared. 16 beams and 48 cubes were cured at room temperature for 28 days, while the other 16 beams and 48 cubes were cured for 28 days and kept for a period of 6 months to be observed for durability with respect to strength after testing. All the beams were tested under three-point loading system with a shear span, av = 2.5d. The results of the compressive strength showed that concrete made with 0.5% jute fibre for 28 days and 6 months gave percentage increase in compressive strength by 12%, 12.5%, 9.7% and 10.1% for grades 25, 30, 35 and 40 N/mm2 respectively compared to the control samples. Percentage increase in shear strength were by 24.5%, 16.1%, 27.9% and 16.5% for concrete grades 25, 30, 35 and 40 N/mm2 respectively compared to the control samples. The addition of the fibre to the concrete slightly reduced the workability of the concrete and increased the crack resistance of concrete.
Wastewater
N. Masne; S. Suryawanshi
Abstract
In this study, natural coarse aggregates were replaced with coarse recycled concrete aggregate (RCA) in 0 %, 50 %, and 100 % extracted from construction and demolition wastes. Their recycling could lead to a greener resolution for preserving the environment and paving the way for sustainability through ...
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In this study, natural coarse aggregates were replaced with coarse recycled concrete aggregate (RCA) in 0 %, 50 %, and 100 % extracted from construction and demolition wastes. Their recycling could lead to a greener resolution for preserving the environment and paving the way for sustainability through solid waste management. The compressive strength of 0 %, 50 % and 100 % RCA at 365 days was reduced by 3.97 %, 4.88 %, 6.81 %, respectively, compared to the compressive strength at 28 days. Tensile strength at 365 days was reduced by 4.31 %, 6.50 % and 9.83 % compared to tensile strength at 28 days. There was no discernible effect of water type on the strength properties of concrete. Compared to other combinations, 100 % RCA concrete experiences a greater percentage of weight loss owing to evaporation of free water. When temperature was elevated, the concrete matrix expands and deep cracks were observed on the concrete surface. The overall performance of recycled aggregate concrete was not much influenced by the use of such aggregates, so these findings will add a new achievement to a sustainable construction through solid waste management.
V. N. Kanthe; S. V. Deo; M. Murmu
Abstract
The assessment of environmental impact on concrete is an important aspect for its durability. The use of supplementary cementitious materials (SCMs) in the concrete can be enhanced the durability. This makes concrete sustainable and reduced environmental issues. In this research paper illustrate the ...
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The assessment of environmental impact on concrete is an important aspect for its durability. The use of supplementary cementitious materials (SCMs) in the concrete can be enhanced the durability. This makes concrete sustainable and reduced environmental issues. In this research paper illustrate the experimental study on the performance of triple blend concrete made up of fly ash (FA) and rice husk ash (RHA) along with ordinary Portland cement (OPC). The current research the concrete composition was used as 20, 30 and 40% cement replacement by FA and RHA. The durability properties such as ultrasonic pulse velocity (UPV), electrical resistivity (ER), water absorption and carbonation depth of triple blend concrete were determined, and for microstructure performance formation factor and Scanning Electron Microscope (SEM) were performed. The improvement in durability was observed up to 40% replacement of cement. The durability of concrete improves with increase in formation factor. The SEM images proved the improvement in particle packing of concrete.
Environment
V. Kanthe; S. Deo; M. Murmu
Abstract
In this research paper, the effect on autogenous healing in concrete by cementitious material such as fly ash (FA) and rice husk ash (RHA) are reported. The utilization of waste byproduct are the interest in research for healing of concrete. The non-destructive testing and microstructure analysis were ...
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In this research paper, the effect on autogenous healing in concrete by cementitious material such as fly ash (FA) and rice husk ash (RHA) are reported. The utilization of waste byproduct are the interest in research for healing of concrete. The non-destructive testing and microstructure analysis were conducted to quantify autogenous healing in concrete. The concrete specimens prepared with different proportion of FA and RHA. The satisfactory results of non- destructive test were obtained with respect to the durability of concrete. In the chemical and microstructure analysis the calcium carbonate crystals formed on healed cracks surface and dense particle packing in the matrix of concrete were observed. This type of ternary blend is useful for making durable and sustainable concrete structure. The utilization of industrial and agricultural byproduct reduces the effect of environmental pollution and also reduces the consumption of cement with the same reduction in CO2 emition from cement industry.
A. A. Nurhanim; I. Norli; N. Morad; H.P.S.A. Khalil
Abstract
Recycling of Construction and Demolition Waste (CDW) aims to minimize the generation of waste and reduce the dependency on natural resources. The aims of the research are to characterize inorganic element and to determine the leaching behavior of CDW (concrete and gypsum) by means of ...
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Recycling of Construction and Demolition Waste (CDW) aims to minimize the generation of waste and reduce the dependency on natural resources. The aims of the research are to characterize inorganic element and to determine the leaching behavior of CDW (concrete and gypsum) by means of the leaching test. The analyzed results were compared with the European Union (EU) Landfill Directive to assess their acceptance criteria. Both wastes were found to have elements of Ca, Mg, Fe, Zn, Mn, Pb, Cu, Cd, As, Cr, Se, Ni, CI and SO42-. The highest concentration and variety of inorganic element found in waste gypsum (WG) were SO42->Ca>CI>Mg>Zn>Cu>Fe. X-ray diffractometric (XRD) analysis proved that the WCo was dominated by quartz, calcite, ettringite, cordierite, diopside and the WG was only dominated by gypsum. The leaching behavior of WG demonstrated pH dependent particularly for the elements of Ca, Mg, Fe, Zn, Cu and Mn but only the elements of Ca and Cr in WCo were shown to be pH dependent in the leaching test. The element of SO42- from the WG indicated a higher reading than WCo without the influence of pH. Noticeably, the concentration of SO42- within the WG strongly require regulation and control before it can be utilized as part of raw materials in the production of environmental friendly recycled building materials.
