Rice husk lean-combustion in a bubbling and atmospheric fluidized bed reactor (FBR) of 0.3 m diameter with expansion to 0.4 m in the freeboard zone and 3 m height was investigated. Experiment design – response surface methodology (RSM) –... more
Rice husk lean-combustion in a bubbling and atmospheric fluidized bed reactor (FBR) of 0.3 m diameter with expansion to 0.4 m in the freeboard zone and 3 m height was investigated. Experiment design – response surface methodology (RSM) – is used to evaluate both excess air and normal fluidizing velocity influence (independent and controllable variables), in the combustion efficiency (carbon transformation), bed and freeboard temperature and silica content in the ashes. Hot gases emissions (CO2, CO and NOx), crystallographic structure and morphology of the ash are also shown. A cold fluidization study is also presented. The values implemented in the equipment operation, excess air in the range of 40–125% and normal fluidization velocities (0.13–0.15 Nm/s) show that the values near the lower limit, encourage bed temperatures around 750 °C with higher carbon transformation efficiencies around 98%. However, this condition deteriorated the amorphous potential of silica present in the ash. An opposite behavior was evidenced at the upper limit of the excess air. This thermochemical process in this type of reactor shows the technical feasibility to valorize RH producing hot gases and an amorphous siliceous raw material.
The huge production of cement concrete is causing environmental issues at one end and the uncontrolled usage of natural resources on the other end. Because of the danger to the ecology, many investigations were being made to use... more
The huge production of cement concrete is causing environmental issues at one end and the uncontrolled usage of natural resources on the other end. Because of the danger to the ecology, many investigations were being made to use industrial by- products as supplementary cementitious material (SCMs) in manufacturing concrete. Ordinary concrete has very low tensile strength, low ductility and bit resistance to cracking. Internal micro-cracks in the concrete and its poor tensile strength is due to the propagation of such micro cracks. Inclusion of Fibers in some percentage enhances the strain properties as well as crack resistance, ductility, bending strength and toughness of concrete. During the past years, we have seen extensive research on concrete by suitably replacing with various materials to reduce carbon footprint and also make it economical. The current review paper primarily focuses on research carried in the territory of fibre reinforced concrete integrating various Mineral Admixtures and Fibres, which involves experimental studies on strength and durability properties, the effect on fibres etc. The recent advancements in fibre reinforced concrete have been af irmed in the current paper. Various mineral admixtures in forms of binary, trinary or quadruple blends with cement added to mono fibre and hybrid fibre reinforced concrete are reviewed. The current review is mainly focused on basalt fibres (BF) and glass fibre (GF) reinforced concretes and their hybridization with various organic and inorganic fibres. To have a clear picture of present study first the effect of incorporating mono fibres, hybrid fibres in conventional concrete and The effect of minerals admixtures (binary, trinary, quadruple blends) on mono fibre and compound fibre reinforced concrete on strength properties are reviewed and discussed followed by their long term durability aspects This review revealed that the hybridization of BFRC and GFRC with blends will result in an enhancement in strength and durability aspects of concrete. However the durability properties of binary, trinary and quadruple blended hybrid fibre reinforced concrete is a concern that hasn’t been meticulously researched yet.
The huge production of cement concrete is causing environmental issues at one end and the uncontrolled usage of natural resources on the other end. Because of the danger to the ecology, many investigations were being made to use... more
The huge production of cement concrete is causing environmental issues at one end and the uncontrolled usage of natural resources on the other end. Because of the danger to the ecology, many investigations were being made to use industrial byproducts as supplementary cementitious material (SCMs) in manufacturing concrete. Ordinary concrete has very low tensile strength, low ductility and bit resistance to cracking. Internal micro-cracks in the concrete and its poor tensile strength is due to the propagation of such micro cracks. Inclusion of Fibers in some percentage enhances the strain properties as well as crack resistance, ductility, bending strength and toughness of concrete. During the past years, we have seen extensive research on concrete by suitably replacing with various materials to reduce carbon footprint and also make it economical. The current review paper primarily focuses on research carried in the territory of fibre reinforced concrete integrating various Mineral Adm...
To contribute the minimization of emissions of greenhouse gas (GHG) into the atmosphere which occurs during the production of cement and to improve the physical properties and mechanical performance of mortars and/or concrete, we have... more
To contribute the minimization of emissions of greenhouse gas (GHG) into the atmosphere which occurs during the production of cement and to improve the physical properties and mechanical performance of mortars and/or concrete, we have incorporated a mineral addition which is the limestone fillers (F-Lime) in their formulation matrix. While partially substituting the clinker by this one at various percentages ranging from 5% to 40% by weight of cement with a step of 5% in presence of a superplasticizer. The influence of the incorporation of F-Lime on the physical properties (fineness by specific surface Blaine /density/setting of initial and final time/water content) was studied on one hand. The effect of the addition of F-Lime on the mechanical performance (compressive strength/porosity/capillary absorption) was evaluated on the other hand. The obtained results by different formulations prospected showed that the addition of F-Lime in the formulation matrix of a cementitious material increases the fineness. Moreover, its density was decreased. We observed that the setting time increases with the percentage of F-Lime was increased. Similarly, the compressive strengths at a young age (2 days), median age (7 days) and long-term (28 days) were improved. The W/C report, the porosity, and the capillary absorption have been decreased. These results show that we have succeeded to produce an ecological and durable cementitious material.
The huge production of cement concrete is causing environmental issues at one end and the uncontrolled usage of natural resources on the other end. Because of the danger to the ecology, many investigations were being made to use... more
The huge production of cement concrete is causing environmental issues at one end and the uncontrolled usage of natural resources on the other end. Because of the danger to the ecology, many investigations were being made to use industrial byproducts as supplementary cementitious material (SCMs) in manufacturing concrete. Ordinary concrete has very low tensile strength, low ductility and bit resistance to cracking. Internal micro-cracks in the concrete and its poor tensile strength is due to the propagation of such micro cracks. Inclusion of Fibers in some percentage enhances the strain properties as well as crack resistance, ductility, bending strength and toughness of concrete. During the past years, we have seen extensive research on concrete by suitably replacing with various materials to reduce carbon footprint and also make it economical. The current review paper primarily focuses on research carried in the territory of fibre reinforced concrete integrating various Mineral Admixtures and Fibres, which involves experimental studies on strength and durability properties, the effect on fibres etc. The recent advancements in fibre reinforced concrete have been affirmed in the current paper. Various mineral admixtures in forms of binary, trinary or quadruple blends with cement added to mono fibre and hybrid fibre reinforced concrete are reviewed. The current review is mainly focused on basalt fibres (BF) and glass fibre (GF) reinforced concretes and their hybridization with various organic and inorganic fibres. To have a clear picture of present study first the effect of incorporating mono fibres, hybrid fibres in conventional concrete and The effect of minerals admixtures (binary, trinary, quadruple blends) on mono fibre and compound fibre reinforced concrete on strength properties are reviewed and discussed followed by their long term durability aspects.
The huge production of cement concrete is causing environmental issues at one end and the uncontrolled usage of natural resources on the other end. Because of the danger to the ecology, many investigations were being made to use... more
The huge production of cement concrete is causing environmental issues at one end and the uncontrolled usage of natural resources on the other end. Because of the danger to the ecology, many investigations were being made to use industrial by- products as supplementary cementitious material (SCMs) in manufacturing concrete. Ordinary concrete has very low tensile strength, low ductility and bit resistance to cracking. Internal micro-cracks in the concrete and its poor tensile strength is due to the propagation of such micro cracks. Inclusion of Fibers in some percentage enhances the strain properties as well as crack resistance, ductility, bending strength and toughness of concrete. During the past years, we have seen extensive research on concrete by suitably replacing with various materials to reduce carbon footprint and also make it economical. The current review paper primarily focuses on research carried in the territory of fibre reinforced concrete integrating various Mineral Admixtures and Fibres, which involves experimental studies on strength and durability properties, the effect on fibres etc. The recent advancements in fibre reinforced concrete have been af irmed in the current paper. Various mineral admixtures in forms of binary, trinary or quadruple blends with cement added to mono fibre and hybrid fibre reinforced concrete are reviewed. The current review is mainly focused on basalt fibres (BF) and glass fibre (GF) reinforced concretes and their hybridization with various organic and inorganic fibres. To have a clear picture of present study first the effect of incorporating mono fibres, hybrid fibres in conventional concrete and The effect of minerals admixtures (binary, trinary, quadruple blends) on mono fibre and compound fibre reinforced concrete on strength properties are reviewed and discussed followed by their long term durability aspects. This review revealed that the hybridization of BFRC and GFRC with blends will result in an enhancement in strength and durability aspects of concrete. However the durability properties of binary, trinary and quadruple blended hybrid fibre reinforced concrete is a concern that hasn’t been meticulously researched yet
Durability of the structures is a main concern now a day due to the various types of deteriorations caused by natural as well as manmade environmental conditions. In this project the durability properties of concrete made with pulverized... more
Durability of the structures is a main concern now a day due to the various types of deteriorations caused by natural as well as manmade environmental conditions. In this project the durability properties of concrete made with pulverized used foundry sand as a mineral admixture is analyzed. The durability of concrete is mostly depends on the surrounding environment. The chemicals present in air and water are the main causes of deterioration of concrete in its life. So a deep study on the action of deteriorating chemicals on the concrete containing pulverized used foundry sand is initiated. Here M40 concrete is prepared with 0%,5%,10%,15% and 20% addition of pulverized used foundry sand to the cement content. Cubes of size 100mmx100mmx100mm were cast and tested for various parameters like Acid resistance with hydrochloric acid and sulfuric acid, Sulphate attack with sodium sulphate and alkali resistance with sodium hydroxide for. The testing was performed on cubes at 28day, 56 day, 90 day and 180 day stored in respective chemicals dissolved in water at 5% concentration. From the test results it is inferred that the concrete containing pulverized used foundry sand is better in acid resistance than ordinary concrete without pulverized used foundry sand. Further the acid resistance for both hydrochloric and sulfuric acid shows an increase up to 15% addition of pulverized used foundry and after that it is slightly reduced. The samples subjected to sodium sulphate and sodium hydroxide has shown no variation in properties with respect to the water cured specimens.
