Behavior of Fiber Reinforced Polymer (FRP) Confined Crumb Rubber Concrete at Elevated Temperatures
Mohammed Faruqi,
Ajibola Habeeb Alamutu,
Breanna Bailey,
Francisco Aguiniga
Issue:
Volume 8, Issue 3, June 2023
Pages:
36-46
Received:
11 May 2023
Accepted:
30 May 2023
Published:
9 June 2023
Abstract: Researchers in engineering and sciences have consistently carried out relevant studies on different ways to minimize the use of natural resources and to control environmental pollution. Aggregates used in concrete are generally obtained from rocks while huge collection of scrap tires are one of the biggest form of wastes in our societies throughout the world. Studies have shown that aggregates in conventional concrete (CC) can be partially replaced with crumb rubber particles. This type of concrete can be referred to as Crumb Rubber Concrete (CRC). Confinement of crumb rubber concrete and conventional concrete have shown to increase their compressive strengths. However, the behavior of CRC confined with Carbon Fiber Reinforced Polymer (CFRP) sheets at elevated temperatures is still unknown. The knowledge and application of this could lead to a cost-effective and practical consideration in fire safety design. Therefore, this study examines the confined compressive strength of CRC confined with CFRP sheets at elevated temperatures. Finite Element Models (FEM) of CC and CRC with and without confinement were developed at room temperature and validated with literature, American Concrete Institute (ACI), and an indirect reference to the real behavior of the material. FEM results agreed reasonably with these sources. Finite element models of confined CC and confined CRC were subjected to elevated temperature and compared with the finite element model of confined CC and confined CRC respectively at room temperature. It was found that models under service confined compressive stress subjected to elevated temperature of 120°C experienced strength loss in the range of 46% to 51% when compared with the room temperature. Accordingly, a strength loss in the range of 34% to 56% was observed for models under maximum confined compressive stress. An example of an axially loaded CFRP-confined CRC column with explanations to calculate the nominal load capacity of a modeled column at room temperature and elevated temperature using our data was also carried out. The percentage difference between the calculated and the model were respectively 3% and 12.1% at room and elevated temperature.
Abstract: Researchers in engineering and sciences have consistently carried out relevant studies on different ways to minimize the use of natural resources and to control environmental pollution. Aggregates used in concrete are generally obtained from rocks while huge collection of scrap tires are one of the biggest form of wastes in our societies throughout...
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Performance Evaluation of an Engine-Operated Weeding Machine
Issue:
Volume 8, Issue 3, June 2023
Pages:
47-65
Received:
17 April 2023
Accepted:
26 May 2023
Published:
27 June 2023
Abstract: Wheat crops are severely hampered by weeds, which also significantly reduce productivity. Manual weeding requires a considerable amount of time and energy. Chemical weed control is harmful to both the environment and mankind. Today's agricultural sector requires non-chemical weed control to meet consumer demand for quality food products and take a proactive approach to food safety. The objectives of the study was to evaluate the performance of an-engine operated weeder by evaluating the weeding efficiency, plant damage, effective field capacity, field efficiency, fuel consumption, performance index, energy consumption, and cost economics of engine operated weeder in wheat crop. The experimental design was a randomized complete block design and evaluation was conducted at three weeder forward speeds (1.5, 2, and 2.5 km/hr), two depths of operation (from 0 to 20 and from 0 to 40 mm), and three levels of soil moisture content (9.4, 12.34 and 15.25%). The performance of the weeder was found to be optimum at 15.25 percent soil moisture content with 0 to 40 mm depth of operation at a forward speed of 1.5 km/hr. The results revealed that maximum weeding efficiency of 90.1 percent was obtained with lower plant damage of 3.31 percent whereas the effective field capacity, field efficiency, fuel consumption, performance index, and energy consumption were found to be 0.052 ha/hr, 85.99%, 0.41 l/hr, 276.78 ha/hp, and 481.71 MJ/ha, respectively. The analysis revealed that forward speed, depth of operation, and soil moisture had significant effects on weeding efficiency, plant damage, effective field capacity, and fuel consumption at P<0.05 level of significance. The cost of weeding per hectare were 758 and 1920 ETBirr/ha for engine-operated weeders and traditional weeding methods, respectively. Based on the performance results, it can be concluded that the weeding machine is efficient, effective, and economically viable option with high scope for acceptability among small and medium scale farmers.
Abstract: Wheat crops are severely hampered by weeds, which also significantly reduce productivity. Manual weeding requires a considerable amount of time and energy. Chemical weed control is harmful to both the environment and mankind. Today's agricultural sector requires non-chemical weed control to meet consumer demand for quality food products and take a ...
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