The Journal of Engineering Research [TJER]

Influence of Reclaimed Asphalt Pavement Aggregates on Strength and Durability Properties of Concrete Mixes in Rigid Pavements

2022-05-16T19:28:24+04:00

The use of Reclaimed Asphalt Pavement (RAP) aggregates in rigid pavements instead of conventional aggregates in Himalayan regions solves the problem associated with shrinking natural resources and dumping of wastes. This study studied the effect of partial replacement of conventional coarse aggregates by RAP in Dry Lean Concrete (DLC) mixes suitable for rigid pavements. A total of 114 specimens (cubical and cylindrical) were cast and tested for mechanical and durability properties as per ASTM and IS code guidelines, partially replaced with CRAP by 25%, 50%, and 75% by weight. The simultaneous effect of fly ash addition by partial replacement of cement by it was also studied. The study concludes that 25% partial replacement by CRAP with 10% fly ash as partial replacement of cement led to the achievement of the strength benchmark as mandated by IRC SP 44 (2014). It was also observed that durability properties such as resistance to acid attack, sulphate attack and carbonation also improved in DLC mixes, including CRAP and fly ash, when compared to control mixes.

Enhanced Biogas Production from Rice Husks and Okra Stalks by Co-digestion with Ostrich Dung and Cow Manure

2022-04-19T14:07:17+04:00

In this study, two sides were studied. First one included single and combined pretreatment which were performed to treat milled rice husks compared to increase the production of biogas untreated rice husks. The other side included investigate the effect of two types of mixing: mixing rice husks and okra stalks using three mixing ratios inoculated with ostrich dung compared to rice husks and okra stalks inoculated with ostrich dung separately and mixing ostrich dung and cow manure using three mixing ratios with rice husks compared to using rice husks inoculated with ostrich dung and cow manure separately. The ten reactors, which were carried out in this study, were in batch mode. Single pretreatment included hydrothermal and oxidative pretreatment with 50% (v/v) H₂O₂, while combined pretreatment consisted of both hydrothermal and H₂O₂ pretreatment. The cow manure was used as inoculum in this anaerobic co-digestion process. The results clarified that the increase of biogas productions were by 5.42%, 48.05%, and 59.07% for hydrothermal, H₂O₂, and combined pretreatment of hydrothermal and H₂O₂, respectively. For first mixing, 25:75 ratio (rice husks: okra stalks) was better than other ratios in the production of biogas (48.77 ml/g VS). In the second case of mixing, 75:25 ratio (ostrich dung: cow manure) was better than other ratios in the production of biogas (21.85 ml/g VS). Kinetic study was applied using modified Gompertz model, and there was well agreement between the predicted and measured values of the all pretreatments with correlation coefficient > 0.95. The pretreatment samples of rice husks and the mixing of materials improve the production of biogas and methane.

Effects of Long-Term Soaking on the Load-Bearing Capacity of Bitumen-Treated Saline Sabkha Soil Subgrade

2023-04-07T00:19:26+04:00

This study delves into the potential of using modified sabkha soil, a low-quality material, as a cost-effective solution for road construction in Kuwait, a country grappling with resource limitations. The research evaluates the effects of adding different percentages of bitumen (0%, 4%, 8%, and 10%) to sabkha soil samples, specifically looking at their load-bearing capacity under long-term soaking conditions. The findings indicate that adding up to 8% bitumen enhances the soil's geotechnical properties and its load-bearing capacity. However, any further addition leads to a decline in these properties. Importantly, the soil's load capacity shows significant improvement under soaked conditions. These encouraging laboratory results suggest that utilizing waste sabkha soil could pave the way for effective soil waste management techniques, thereby addressing environmental concerns related to sabkha soil disposal.

State-of-the-Art Review on Utilization of Fly Ash in Pavement Structures

2022-07-03T14:37:14+04:00

The use of fly ash in construction has been on the rise, yet its application in pavement construction remains relatively underexplored. This study addresses this gap by critically reviewing 70 years of research on fly ash usage in pavement engineering, offering valuable recommendations. Class 'C' fly ash is employed for soil stabilization, while class 'F' is used in concrete. In both flexible (asphalt) and rigid (concrete) pavements, fly ash primarily functions as a filler material. Fine ash, owing to its fineness, enhances asphalt concrete by reducing void ratios and water sensitivity, as well as easing subgrade compaction while increasing compressive strength. Incorporating fly ash into Hot Mix Asphalt (HMA) enhances resistance to cracking and oxidative ageing. Adding fly ash (up to 25%) significantly boosts soil failure stress and strain values by 106% and 50%, respectively, while a combination of 8% lime and 18% fly ash yields maximum shear strength. A modest amount of lime (1-2%) mixed with 10% fly ash achieves a maximum dry density of 1.98 gm/cm3 at an optimal water content of 12.62%. Additional testing by researchers corroborates and validates the findings of this literature review.

A Quick and Comprehensive Method for Determining Static ATC with NRS and VFT

2023-03-05T13:32:36+04:00

Electricity market players prioritize available transfer capability (ATC) as an attractive solution. Market participants can gain a financial advantage through accurate and fast ATC solutions. In order to provide a suitable and valuable solution, we use differential load flow equations. A dynamic system's entire time-domain trajectory can be solved by this method, along with a fictional time-domain differential equation. This article uses Newton-Raphson-Seydel instead of Newton-Raphson, which can also be used to determine voltage stability. A variable frequency transformer (VFT) was used in this study to increase and control transmission power. A 50% time saving on small systems was achieved with the proposed method, which was applied to seven different systems. In addition, it performed better on large systems by more than 90%. This proposal for static ATC presents promising results and can be applied to online applications.

HAZard and OPerability Study Analysis as a Semi-Automatic Approach

2023-03-05T10:34:01+04:00

Risk analysis is crucial in industrial conception. HAZOP is the top risk analysis method for the oil and gas sector. This paper presents a semi-automatic method to address HAZOP's limitations and produce automatic results. The method uses a knowledge base, initially filled with gas liquefaction data, and is enhanced with subsequent case studies. An inference engine processes this data to conduct a HAZOP study. Propagation rules identify potential deviation paths, enabling risk analysis and consequence prediction based on the knowledge base. This method uniquely illustrates deviation paths and introduces nodes along these paths for further study. The findings derive from dynamic knowledge of each system in the knowledge base and can be reviewed and amended by experts.

Chemical Risk Assessment and Prevention Action Plan Related to Petroleum Production. Case Study of Laboratory and Storage Units in an Algerian Oil and Gas Company

2022-12-17T21:42:35+04:00

Chemical risk is considered one of the most frequent risks in the workplace, affecting the safety of workers continuously exposed to chemical substances. In addition, it can have an environmental impact and cause an explosion when unacceptable conditions are met. To know the effects of chemical risks and how to prevent them, this study is proposed, the main objective of which is the evaluation of chemical hazards and the proposal of an action plan to avoid this kind of risk in industrial companies. Our case study focused on the crude oil production company " PERTAMINA" using the SEIRICH software. The results indicate that most chemicals are hazardous and can cause serious harm to workers exposed to them periodically. Therefore, the proposed preventive action plan for safety improvement aims to ensure continuous development in oil and gas field production, processing, and distribution, taking into account the health and safety of workers.

A Novel Demulsifier Used to Separate Water from the Emulsion

2023-01-30T10:15:02+04:00

Recently, there has been interest in using chemical demulsifiers to separate the water phase from crude oil emulsion. Separating the water from the emulsion is crucial before transportation and refining to avoid complications from the water phase. This research introduces a novel chemical demulsifier, Poly (AAc-co-AAm) hydrogel, synthesised at Sebha University. Its characteristics were examined using the Fourier Transform Infrared Spectroscopy test (FTIR). Its efficiency was tested against commercial demulsifiers (Emulsotron and Dmo-66813) used in some Libyan oil fields. The chosen concentrations for Poly (AAc-co-AAm) were 0.5%, 1%, and 2%, while commercial demulsifiers were tested based on the standard method in the oil field. The results revealed that Poly (AAc-co-AAm) outperformed the commercial demulsifiers in terms of separation time, volume, and quality. Notably, the 0.5% concentration of Poly (AAc-co-AAm) provided the best separation results.