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This study investigates the impact of the fire decay phase on structural damage using the sectional analysis method. The primary objective of this work is to forecast the non-dimensional capacity parameters for the axial and flexural load-carrying capacity of reinforced concrete (RC) sections for heating and the subsequent post-heating phase (decay phase) of the fire.

The sectional analysis method is used to determine the moment and axial capacities. The findings of sectional analysis and heat transfer for the heating stage are initially validated, and the analysis subsequently proceeds to determine the load capacity during the fire’s heating and decay phases by appropriately incorporating non-dimensional sectional and material parameters. The numerical analysis includes four fire curves with different cooling rates and steel percentages.

The study’s findings indicate that the rate at which the cooling process occurs after undergoing heating substantially impacts the axial and flexural capacity. The maximum degradation in axial and flexural capacity occurred in the range of 15–20% for cooling rates of 3 °C/min and 5 °C/min as compared to the capacity obtained at 120 min of heating for all steel percentages. As the fire cooling rate reduced to 1 °C/min, the highest deterioration in axial and flexural capacity reached 48–50% and 42–46%, respectively, in the post-heating stage.

The established non-dimensional parameters for axial and flexural capacity are limited to the analysed section in the study owing to the thermal profile, however, this can be modified depending on the section geometry and fire scenario.

The study primarily focusses on the degradation of axial and flexural capacity at various time intervals during the entire fire exposure, including heating and cooling. The findings obtained showed that following the completion of the fire’s heating phase, the structural capacity continued to decrease over the subsequent post-heating period. It is recommended that structural members' fire resistance designs encompass both the heating and cooling phases of a fire. Since the capacity degradation varies with fire duration, the conventional method is inadequate to design the load capacity for appropriate fire safety. Therefore, it is essential to adopt a performance-based approach while designing structural elements' capacity for the desired fire resistance rating. The proposed technique of using non-dimensional parameters will effectively support predicting the load capacity for required fire resistance.

The fire-resistant requirements for reinforced concrete structures are generally established based on standard fire exposure conditions, which account for the fire growth phase. However, it is important to note that concrete structures can experience internal damage over time during the decay phase of fires, which can be quantitatively determined using the proposed non-dimensional parameter approach.

This paper aims to present a mathematical model of predicting the residual moment capacity of fire-damaged reinforced concrete (RC) elements after cooling to ambient temperature which also reflects the role of bond between steel rebar and surrounding concrete.

The prediction of residual moment capacity of fire-damaged RC element has been carried out for two scenarios: by assuming perfect bond between surrounding concrete and steel rebar after fire exposure and by incorporating a relative slip between surrounding concrete and steel rebar and hence assuming partial bond between them after fire scenario. The predicted results are then compared with the experimental results available in different literatures.

It is found that on comparison between the predicted results and the experimental results, the proposed mathematical prediction model, when bond-characteristics are considered, shows better agreement with the experimental results as compared with those by conventional method with perfect bond assumption.

The constitutive relationship for thermal residual properties of steel rebar and concrete has been used in the proposed prediction model along with relative slip approach between surrounding concrete and steel rebar after fire scenario and consequently to predict the residual moment capacity of the fire-damaged RC element after cooling.

The main aim of this research was to investigate the effectiveness of various strengthening techniques in restoring the structural performance of reinforced concrete (RC) beams damaged by elevated temperatures.

Three different strengthening techniques, namely, high-strength fibre reinforced concrete (HSFRC), ferrocement (FC) jacketing and externally bonded fibre-reinforced polymer (FRP) were used. Series of RC beams were casted, heated, strengthened and tested to investigate the influence of various variables. The variables of the study were type of strengthening and level of heat damage.

Externally bonded FRP was found to be the best among the various techniques, especially with respect to strength and stiffness restoration. On the contrary, the FRP strengthening was not that effective in restoring the energy absorption capacity of beams compared to HSFRC and FC techniques of strengthening. The chosen strengthening techniques were able to restore the failure mode of beams to flexural failure, which was found to have changed to shear failure in case of heated unstrenghthened beams.

This research program has contributed to the fundamental understanding of designing post fire retrofit solutions for RC beams.

In present study, a full-scale testing of reinforced concrete (RC) frame sub-assemblage has been investigated under fire subsequent to simulated seismic loading. First part of the sequential loading consisted of a quasi-static cyclic lateral loading corresponds to life safety level of structural performance on the test frame. In the second part of the test, a compartment fire was ignited to the pre-damaged test frame for one hour duration simulating fire following earthquake (FFE) scenario. The results showed that the first cracking was observed at the end joints of the roof beams after the frame experienced a 30 mm cyclic lateral displacement. One hour heating and eleven hour cooling was tracked and temperatures were recorded. A knocking sound was heard from the fire compartment after 5 minutes of the fire ignition. An excessive degradation of the concrete material at a number of locations of the frame sub-assemblage was observed during visual inspection after the fire test. The Nondestructive tests (NDT) were also conducted to ascertain the damage in the RC frame at the various stages of loading. The test results developed an understanding of the behaviour of RC frame sub-assemblage in FFE.

The paper presents a comparative study of thermal properties of reinforced concrete structural elements. A total of 2 beams and 2 columns were selected from literature [1-3]. Thermal profiles of these elements were predicted using different thermal properties and were compared with the experimental results. The thermal analysis is carried out numerically using finite element analysis package, ABAQUS [4]. Comparisons of different analyses results have been made with the main focus laid on the effect of the boundary conditions i.e. prescribed temperature boundary condition, convection and radiation. During the heating phase, there was slight difference in the temperatures predicted using the two boundary conditions, whereas during cooling phase, there was a significant difference: the convective and radiation boundary condition yielded better results. A reduction in discrepancy between the simulated and experimental result was observed on using thermal properties as per the formulation in Eurocode2 which took into account the moisture content.

Evaluation of mechanical properties of undamaged and damaged steel rebars at elevated temperature finds its applications in development of steel material models likely to be used in designing reinforced concrete structural members subjected to earthquake triggered fire. In the present experimental investigation, 84 rebar specimens (cylindrical) of length 700 mm and diameters 8 mm, 10 mm, 16 mm and 20 mm were tested. Test specimens were prepared from the materials used in construction of full-scale reinforced concrete frame subjected to earthquake and fire. The specimens were initially stressed to a certain known limit (0.58 times yield stress f_y) to simulate damage caused by an earthquake. After inducing the damage, they were exposed to a desired temperature level (20 °C, 250 °C, 500 °C and 750 °C) in a circular furnace arrangement coupled with a 400 kN universal testing machine. The temperature was sustained inside the furnace for about 30 minutes to ensure a steady state heat transfer inside the specimen. The bars were then tested under uniaxial tensile loading conditions to failure. The elongation was recorded by using two LVDTs fixed between gauge lengths of 265 mm at the mid-height. Results obtained in the tests were utilized to carry out multiple linear regression analysis and propose constitutive models for damaged steel rebars and various relationships: Tensile Strength, Peak-Strain, Elongation and Elastic Modulus vs. Temperature, Stress vs. Strain at elevated temperatures.

Cummins Generator Technologies India Limited (CGTIL) was in the process of setting up a world-class factory at Ranjangaon based on “lean” production principles. The project team, however, went a step ahead and married “green” with “lean”. While lean is about taking the system inefficiencies out, the green is about harmony with nature. The case is about CGTIL's journey of deriving synergies between seemingly conflicting objectives of lean and green.

The study applied the stimulus–organism–response (S–O–R) framework to investigate the influence of flow elements (e.g. perceived control, concentration and cognitive enjoyment) on artificial intelligence (AI)-enabled e-tail services in evoking awe experience in online fashion apparel context.

Data of 739 active users of online fashion retail shoppers were collected using Amazon Mechanical Turk (MTurk). Partial least square-structural equation modeling was used for analysis.

This study suggested the relevance of AI-enabled services in evoking flow and stimulating the customers' awe experience in online fashion shopping.

The use of AI could help online fashion retailers to improve the experiential elements by using stimuli that evoke feelings of vastness, novelty and mysticism.

The study offers insights about the relevance and applicability of AI in enhancing the flow elements and awe experience on online fashion apparel shopping in an emerging economy.

Human Resource Management (HRM), Industrial Relations, Labor Law (Indian business context), Organizational Behavior, Trade Union and Employer-Employee Relationship.

Academic students (MBA and BBA), management trainees, HR managers and top management of organizations interested in understanding the importance HRM practices.

This case describes an Industrial Relations situation in an automobile company in India. It begins with the mention of Maruti Suzuki India Limited's (MSIL) brush with an unprecedented labor violence that rocked its Manesar facility on July 18, 2012, eventually leading to the lock out of the same on July 21, 2012. Further, it describes the background of the company, employer-employee relationship, a series of strikes experienced by the company, incidents that led to the violence, incidents that happened on the day of violence and finally actions taken after the violence by the company, the government and the union. With such details, the case raises questions on the prolonged people management issues afflicting MSIL. It endeavors to educate the discussants on the specifics of an industrial relations system and the role of each actor toward maintaining industrial peace.

Understanding the role of actors of industrial relations toward effective HRM in the organization. Analyzing the compliance of the actors under the existing labor laws as applicable to the organization. Comprehending the attitude of employees, employers and industry toward each other and also toward the job. To understand the nuances of people management function and its contribution toward the violence that eventually resulted in lockout. To comprehend various organizational behavior concepts that shall help synergize the employees' objectives and employer's goal. To analyze the complete incident with relevant organizational and industrial relations (IR) theories.

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