Glass Ceiling Research Articles

Experimental and numerical research on seismic behavior of end-plate connection beam-column joints considering concrete floor effect

With the aims to study the seismic performance of the end-plate connection (EPC) joint with concrete floor, four full-scale specimens with different configuration (two specimens in major direction, and the other in minor direction) of the pseudo-static cyclic loading tests were conducted. Based on the failure criteria, the mechanical behaviors and failure modes of the specimens were investigated, including major and minor connection directions. The hysteresis response, bearing capacity, stiffness evaluation, and energy dissipation of the specimens were evaluated, and with a average ductility coefficient value of all specimens is about γ = 4.0. Meanwhile, to analyze and verify the accuracy of experimental results, the nonlinear models of the specimens were performed in ABAQUS software. In addition, a series of parametric analysis were performed to study the influence of axial compression ratios, thickness ratios (the ratio(η1) of end-plate thickness to column flange thickness, and the ratio(η2), of end-plate thickness to column web thickness), and concrete compressive strength on the joint seismic performance. This parametric analysis result indicates that increasing the thickness ratio and concrete compressive strength reasonably can effectively improve the seismic behavior of the overall joint with the concrete floor, especially in minor direction joints.

Optimizing the Location of Supports under a Monolithic Floor Slab

Monolithic reinforced concrete floor slabs are one of the most common types of building structures, and their optimization is an urgent task. The article presents the methodology for finding the optimal position of point supports under a reinforced concrete floor slab of arbitrary configuration at arbitrary load. The slab is considered thin, elastic and isotropic, with constant over-the-area stiffness, that is, the reinforcement is not taken into account or is constant. The solution is performed using the finite element method in combination with the nonlinear optimization methods. Finite element analysis is implemented by authors in MATLAB (R2024a) environment in such a way that the location of the columns may not coincide with the nodes of the finite element mesh of the slab. This allows to significantly increase the efficiency of solving the optimization problem compared to previously used algorithms, including the Monte Carlo method. Boundary conditions are taken into account using the Lagrange multiplier method. As an optimization criterion, the maximum deflection value is used, as well as the value of the potential strain energy. The effectiveness of six nonlinear optimization methods is compared in the example of a square slab under the action of a uniformly distributed load. For solutions obtained using the pattern search, simulated annealing and internal point methods, the maximum deflections are at least 1.2 times higher than for solutions obtained using the particle swarm method and genetic algorithm. An example of real object optimization is also presented. By changing the position of seven columns, it was possible to reduce the maximum deflection of the floor slab by 1.6 times.

Long-Term Behavior of Timber–Concrete Composite Structures: A Literature Review on Experimental and Numerical Investigations

Timber–concrete composite structure is a type of efficient combination form composed of concrete floors and timber beams or floors through shear connectors, and shows good application potential in the floor system of timber buildings. The long-term performance of the timber–concrete composite structures is complex and is affected by the creep of timber and concrete, as well as the long-term slip of the shear connectors. This article presents a comprehensive overview of the research status on the long-term behavior of timber–concrete composite members and different shear connectors. For the shear connectors, the effects of loading levels, environments, and component materials on their creep coefficients are summarized. As to the timber–concrete composite members, both the experimental and numerical investigations are gathered into discussions: the connection types, component materials, loading conditions, and durations in the long-term tests are also discussed; various models for describing long-term behavior of timber, concrete, and connection systems are provided, and then a comprehensive description of the progress of numerical investigations over the last decades is made. In addition, the suggestions for future research are proposed to reach a clearer understanding of the bending mechanisms and mechanical characteristics of timber–concrete composite structures.

Breaking Archaeology's glass ceiling in technological innovation. Comment on “Snakes and ladders in Paleoanthropology: From cognitive surprise to skillfulness a million years ago” by H.M. Manrique, K.J. Friston & M.J. Walker

Breaking Archaeology's glass ceiling in technological innovation. Comment on “Snakes and ladders in Paleoanthropology: From cognitive surprise to skillfulness a million years ago” by H.M. Manrique, K.J. Friston & M.J. Walker

A dynamic discrete model of ventilated concrete floor integrated with solar air collector under the effect of uneven direct solar radiation

Abstract A system combining the ventilated concrete floor (VCF) with solar air collector (SAC) in buildings has been applied in the western Sichuan Plateau for nighttime heating. However, the dynamic model coupled with uneven solar radiation of SAC-VCF is absent, thus the thermal behavior of the system is difficult to predict in practice. In this research, a coupled model is built to predict the thermal characteristics of the room with the SAC-VCF system under uneven solar radiation. The calculation model of VCF considers the uneven distribution of solar radiation on the floor surface, established by combining the resistance-capacitance (RC) network model and the number of transfer unit model (NTU) using the discrete method and validated by experimental data. A 3R2C model is utilized to model envelopes, validated by simulation results. The calculation error of surface temperature and room air temperature is within 5%. Then a case study is conducted with the validated model to predict the thermal performance of the SAC-VCF system with even and uneven solar radiation. Results indicate that under uneven solar radiation, the local surface temperature significantly increases to 35.1 °C, 9.1 °C higher than even solar radiation. Meanwhile, under uneven solar radiation, the heat transfer of supply air and surface of VCF is increased by 14% and 6%, respectively. Besides, the room air temperature is almost equal of two cases, while the operative temperature is 0.4 °C lower under uneven solar radiation. The model is beneficial to further study the influencing factors of this system.

Diagnostics of premature damage to surface-hardened industrial concrete floors

The article presents the diagnostic results on surface-hardened industrial concrete floors. Selected examples of floors showcased premature damage to surface layers, characterized by intense dusting, delamination, and local spalling, while the structural system remained unaffected. Quantitative petrographic analysis of concrete was applied to core specimens from the floors, involving the examination of digital images from a polarizing optical microscope and a scanning electron microscope. The hardening compound and powdered specimens of the cement matrix were characterized using differential thermal analysis and X-ray diffraction. A multiple microindentation method was employed to assess local variations in mechanical properties. Concrete cross-section analysis revealed areas with a non-uniform distribution of air voids, identified regions exhibiting increased porosity, highlighted areas of cracking in the concrete, indicated local variability in the phase composition of cement hydration products, and pointed out the presence of carbonated areas. The causes of the damage were discussed based on these findings,. The crucial role of quantitative petrographic analysis in diagnosing premature surface damage to industrial floors was demonstrated.

Corrigendum to “How Glass Ceilings and Iron Rice Bowls Create “Glass Bowls”: Gendered Barriers and Protections in Public Sector Employment in South Korea”

Corrigendum to “How Glass Ceilings and Iron Rice Bowls Create “Glass Bowls”: Gendered Barriers and Protections in Public Sector Employment in South Korea”

SELECTION OF OPTIMAL PARAMETERS OF A LIGHTWEIGHT FLAT FLOOR WITH VOIDS MADE OF PLASTIC BALLS

Formulation of the problem. Architectural and construction design of buildings using reinforced concrete has led to an increase in the number of objects with an individual space-planning structure, a rich variety of facade and volumetric solutions. Today the question of the effectiveness of using flat prefabricated monolithic lightweight floors in the construction of multi-storey buildings with individual space-planning and architectural solutions is relevant. In a market economy interest in the issue of rational use of resources, namely the cost of concrete and reinforcement in construction, has sharply increased, which is directly related to attracting investment. As it is known, when designing buildings from prefabricated monolithic reinforced concrete, in contrast to prefabricated concrete, there is greater freedom in adopting the space-planning parameters of the building, and there may also be simpler design solutions, in particular for floors. The constructive solution of floors depends on numerous requirements for the building as a whole and directly for the floor. One of the requirements that influences the attraction of investments is a small material-intensive floor covering with significant spans of buildings of various structural systems. The effective use of lightweight precast monolithic reinforced concrete floors with voids made of plastic balls in construction requires a comprehensive technical and economic analysis of this innovative solution for the precast monolithic reinforced concrete floor structure. The purpose of the article is to perform a technical and economic comparison of various design options for a flat lightweight prefabricated monolithic floor. The influence of floor parameters on the consumption of concrete and reinforcement is considered. Conclusion. As a result of the research, it was established that it is rational to use hollow balls made from recycled materials as a material for making voids from balls in flat floors. Moreover, all studied floor options with spans of 6 m, 7 m, 8 m and void sizes made of balls with diameters of 180 mm, 315 mm and 50 0mm meet the requirements of the first and second groups of limit states.

The ‘glass ceiling’ of Germany’s socio-ecological transformation: Citizen, expert, and local stakeholder perspectives on responsibility for change

The IPCC (2022) underscores the urgent need to transform economic and social systems to stay within the ~1.5 °C warming threshold, with the pressure placed on states to lead the processes of transformation. Germany’s market economy is currently neither socially nor ecologically sustainable, requiring a socio-ecological transformation towards sustainable consumption and production systems. As the imperatives of the modern democratic welfare state require high levels of material welfare, economic growth and legitimation through (over)consumption, there is currently a “glass ceiling” to any such transformation. Through a combination of empirical research methods, including 11 expert interviews, a gamified citizen workshop with 22 citizens, and a local stakeholder workshop with 27 stakeholders, this paper explores the readiness and perspectives of German citizens, experts, and local stakeholders for a socio-ecological transformation. The findings highlight the contradictory role given to the state in the transformation, the difficulties of transforming “imperial modes of living”, and the collective evasion of responsibility, which suggests a “glass ceiling” to transforming the German market economy into a genuinely social and ecological model.

Mesh-based topology, shape and sizing optimization of ribbed plates

In this paper, we present a new parameterization and optimization procedure for minimizing the weight of ribbed plates. The primary goal is to reduce embodied CO2 in concrete floors as part of the effort to diminish the carbon footprint of the construction industry. A coupled plate-beam finite element model and its computational mesh enable simultaneous topology, shape and sizing optimization of ribbed plate systems. Using analytical sensitivity analysis and gradient-based optimization, we achieve significant weight reductions in the range of 24–57%, in comparison to reference designs with regular ribbing patterns. The results strengthen the argument in favor of ribbed plates as a structural system that can serve the environmental goals of the construction industry. While our focus is on ribbed concrete plates in buildings, the proposed mesh-based design parameterization is applicable in the general case of optimizing stiffened shells—with potential contributions also to automotive and aerospace applications. All computer codes used in this study are freely available through a public repository, https://zenodo.org/records/11489996.

A Study of Glass Ceiling in the Higher Educational Sector of India

A Study of Glass Ceiling in the Higher Educational Sector of India

The Need to Practice What We Teach: Revisiting the Sticky Floor Effect in Five Southern U.S. States’ Public Universities

Administrative appointments throughout higher education are sought after, highly coveted positions that exhibit power and authority for many as they become leaders. Historically, males have held a majority of these positions. Johnson, Long, and Faught (2014) found “a clear discrepancy exists” (p. 29). This study revisits the research of Johnson, Long, and Faught in examining the gender composition of public university administrators, following the chain of command from the colleges of business upwards, in five southern U.S. states. As in the original research, this study investigates the presence and prevalence of the sticky floor effect and the perceived fair employment practices of universities in applying diversity concepts within their institutions 11 years after the initial study.

Vibration response of ultra-shallow floor beam (USFB) composite floors

This paper examines the vibration response of the steel-concrete composite Ultra Shallow Floor Beam (USFB®) flooring system which incorporates asymmetric steel perforated beams to accommodate the concrete floor slab within the depth of the flanges while allowing reinforcement and/or service ducts to pass through the web openings. This is a lightweight flooring system that can accommodate long spans, thus becoming susceptible to floor vibrations due to external resonant dynamic loads. To investigate the influence of slab thickness and boundary conditions on the natural frequencies of the USFB flooring system, parametric studies are conducted using a finite element model and five floor spans. The model was first validated against an experimental test conducted by the authors. Emphasis is placed on the fundamental frequency to predict the possibility of resonance of this complex flooring system with typical human-induced dynamic loads in building structures. To further facilitate the practical numerical modelling and vibration analysis of buildings with USFB floors in standard commercial structural software, an analytical method of deriving equivalent isotropic plate properties is developed and its accuracy is numerically verified vis-à-vis with detailed ABAQUS models.

Glass ceiling in Nigeria’s banking sector: perspectives of senior male employees

PurposeThis study aims to examine senior male employees’ perspectives on the glass ceiling in the Nigerian banking sector.Design/methodology/approachThe data were collected qualitatively using interviews with 43 senior male employees in four Nigerian banks.FindingsThis study finds that senior male employees acknowledge the challenges their female counterparts face concerning promotion. Senior male employees’ views on the value of gender-diverse leadership underscore the illusion of a “level playing field” because of a gender-neutral performance policy and a family–friendly policy for women. Nonetheless, the study notes a divergence in senior male employees’ perspectives about the professional progression of female employees (based majorly on age and ethnicity). The study concludes that the organisational culture and leadership that underpin poor female career progression are embedded in and driven by the culture in the empirical context.Originality/valueThe examination of senior male employees’ perspectives on the glass ceiling in the Nigerian banking sector offers significant theoretical and practical contributions to the extant literature on gendered occupational segregation by providing unique insights into how patriarchal societal and occupational culture, as well as (limited) family–friendly policies for women, influence the configuration of men’s views of gendered occupational segregation in the Nigerian banking sector.

Clearing the smog ceiling: The impact of women’s political empowerment on air quality in European regions

This study explores the impact of female political empowerment on air quality outcomes. Women’s stronger environmental concerns and pro-environmental behaviors may lead to better air quality as they progressively break the glass ceiling in politics. To test this hypothesis, we employ a novel data set on regional air pollutant emissions and women’s political empowerment for a sample of 230 European regions of 27 EU countries. We apply instrumental variables and partial identification methods to ensure that our results are not influenced by confounding variables. We find that female political empowerment is consistently associated with improved air quality.

Enhancing durability and sustainability of industrial floors: A comparative analysis of dry-shake surface hardeners

This study investigates the development of a cost-effective and sustainable dry-shake surface hardener for enhancing the durability of industrial concrete floors. Utilizing locally sourced materials, the research aimed at not only ensuring the hardener's strength and finish but also its economic viability and environmental friendliness. Fourteen unique mixtures were formulated by altering the sand ratios and incorporating superplasticizers to optimize the composition. These mixtures underwent rigorous testing over 7, 14, and 28 days, evaluating their compressive and flexural strengths, flowability, water absorption, and impact resistance. The findings revealed that the modified floor hardener, specifically the FH-12 mixture, exhibited superior performance across all tested parameters. It showed higher compressive and flexural strengths, enhanced impact resistance, and reduced water absorption compared to other variants and commercially available hardeners. Notably, the use of finer coarse sand and the adjustment of superplasticizer quantities significantly contributed to these outcomes. This breakthrough demonstrates the potential of employing locally available materials to create a durable, cost-effective, and environmentally friendly solution for industrial flooring. The study underscores the importance of material characterization and methodical formulation in developing construction materials that meet the dual criteria of performance and sustainability. This option is preferred for its lower environmental impact and compatibility with sustainable practices, contributing to Sustainable Development Goal 9 on industry, innovation, and infrastructure. It highlights the role of floor hardeners in global sustainability efforts.

Revisiting “Glass Ceilings and Sticky Floors”: A Commentary on Navigating Gender in Higher Education

Revisiting “Glass Ceilings and Sticky Floors”: A Commentary on Navigating Gender in Higher Education

When Push Comes to Shove: An Experimental Analysis of Voter Support of a Woman President and the 2024 Nomination

A woman has not yet shattered the “hardest, highest glass ceiling” of the American presidency. Our research answers two questions: Which groups are more likely to believe electing a woman president to be historically important? (R1), and When a presidential election is at stake, who is likely to support a woman candidate? (R2). Using observational data ( n = 1075), our findings indicate that women, people who recognize sexism within politics, Democrats, and liberals are more likely to view a woman president as historic. Utilizing a list experiment of hypothetical 2024 presidential matchups, few who claimed to view a woman president as historic were willing to cast a vote in their favor. When push came to shove, Democratic women were the group most likely to vote for a woman presidential candidate. As parties look toward the future, this study offers insight into how voters respond to potential nominees and who parties will nominate.

Feasibility of Using Lightweight Load-Bearing Panel Systems in Duplex Apartments of Tall Buildings

As an inevitable result of the growing population in recent times, the requirements of housing facilities, land scarcity, and overexploitation of natural resources have created many problems. One solution for the lack of land is to have multi-storey apartment buildings. Hence, over the last few decades, the number of tall buildings has seen an exponential increase. The apartment spread over two floors, is considered upmarket due to the larger floor area. However, one factor that has been a huge obstruction to promoting duplex apartments is the higher cost. In this study, a novel concept is introduced where a proper load-bearing floor is needed only once on two floors. The duplex is double-height, using lightweight concrete panels supporting lightweight concrete floors. Recycled expanded polystyrene (REPS) based light-weight panels are used as the load-bearing walls, and the NERD slab system is introduced for the intermediate floor. The structural performance was assessed using the comparison of two finite element models for duplex and conventional concepts. It was observed that the duplex concept is structurally feasible in comparison with the conventional concept. The study emphasises that an approximately 30% dead load reduction in typical floor levels has occurred due to the lightweight beam slab system in between floors.

A Comparative Model of Thermal Performances Between a Modern and Classic Habitat for A Hot and Humid Tropical Climate: Case of Guinea

The objective of this research is to carry out a comparative study between a classic habitat and a modern habitat in order to understand which of the two is more efficient for a humid tropical area. To do this, a digital modeling of the heat transfer phenomena in the different components of the habitat was highlighted for a habitat made of stabilized earth bricks, a roof made of transparent tiles, false ceilings made of rectangular panels containing phase change material, concrete floor and a classic habitat made from local materials is presented. To show the reliability of this study, we validated our habitat model integrating phase change material through an experimental study carried out by researchers B. ZIVKOVIC and I. FUJII. A study on the temperature distributions at the level of certain components of the habitat done, and the influence of the variation of certain parameters was highlighted to know the thermal behavior of the two habitats. Furthermore, a comparative study was performed between the interior and exterior temperatures of the south walls of habitats incorporating PCM and without PCM, which are the components most exposed to solar radiation whose maximum values are respectively 33°C and 34, 5°C and 33.15°C against 47°C. Keywords: Performances, thermal, bioclimatic, PCM, Tropical climate, Guinea.