Search Results (9)

This paper addresses three research questions: (1) According to the pertinent literature, what are the main causes of the current gender gap in the construction industry, particularly for management and leadership roles? (2) Is there a significant difference between male and female high-school-age students regarding their level of knowledge of the construction industry? (3) Is there a significant difference between male and female high-school-age students in their perception of the construction industry and factors impacting their career choice? These research questions are addressed by a review of the literature followed by a discussion of precamp survey results from two consecutive years of a two-week high school summer camp, which is focused on construction science and management. The literature review reveals that the issues are deep-routed and complex but can in general be categorized into two groups: the recruitment and retention of women in construction management and related careers. While the literature review summary in this paper addresses both categories, the focus of the paper remains recruitment, particularly through a study of high school students’ level of knowledge and perceptions of construction management. The pre-camp surveys assessed the participants’ baseline knowledge and perceptions of construction management as a career. The results showed that the knowledge of construction management as a career is very low, with no statistically significant difference between genders. It must be noted here that the participants are biased positively toward the construction management and related careers, as they chose to attend the camp for a variety of reasons, from wanting an experience on the campus of this university to parents’ encouragement. Despite this baseline interest, however, the data show that the participants lacked clarity on what this career really entails. It is suggested, therefore that the general knowledge of this career path across larger and more randomized samples across U.S. will be even lower. The perceptions of the construction industry differed slightly between genders, with females perceiving it as more physically challenging and prioritizing family friendliness when considering career options. In conclusion, both the literature review and the survey data analysis show that the lack of knowledge of this career path, exacerbated by the negative perceptions of the construction industry, contribute to the problem of women not choosing to study construction management. The construction industry continues to make significant improvements in their diversity and inclusion efforts, and there are a variety of paths within the industry for graduates of construction science and management degrees. As such, significant work remains for both the industry and academia to overcome the lack of knowledge and negative perceptions of the industry through increased outreach to better inform high school students, parents, and counselors. Full article

The educational applications of extended reality (XR) modalities, including virtual reality (VR), augmented reality (AR), and mixed reality (MR), have increased significantly over the last ten years. Many educators within the Architecture, Engineering, and Construction (AEC) related degree programs see student benefits that could be derived from bringing these modalities into classrooms, which include but are not limited to: a better understanding of each of the subdisciplines and the coordination necessary between them, visualizing oneself as a professional in AEC, and visualization of difficult concepts to increase engagement, self-efficacy, and learning. These benefits, in turn, help recruitment and retention efforts for these degree programs. However, given the number of technologies available and the fact that they quickly become outdated, there is confusion about the definitions of the different XR modalities and their unique capabilities. This lack of knowledge, combined with limited faculty time and lack of financial resources, can make it overwhelming for educators to choose the right XR modality to accomplish particular educational objectives. There is a lack of guidance in the literature for AEC educators to consider various factors that affect the success of an XR intervention. Grounded in a comprehensive literature review and the educational framework of the Model of Domain Learning, this paper proposes a decision-making framework to help AEC educators select the appropriate technologies, platforms, and devices to use for various educational outcomes (e.g., learning, interest generation, engagement) considering factors such as budget, scalability, space/equipment needs, and the potential benefits and limitations of each XR modality. To this end, a comprehensive review of the literature was performed to decipher various definitions of XR modalities and how they have been previously utilized in AEC Education. The framework was then successfully validated at a summer camp in the School of Building Construction at Georgia Institute of Technology, highlighting the importance of using appropriate XR technologies depending on the educational context. Full article

The timing, amount, and quality of sleep are critical for an individual’s health and quality of life. This paper provides a focused narrative review of the existing literature around multidimensional environments and sleep health for aging adults. Five electronic databases, Scopus, Web of Science, PubMed/Medline; EBSCOhost, PsycINFO (ProQuest), and Google Scholar yielded 54,502 total records. After removing duplicates, non-peer reviewed academic articles, and nonrelevant articles, 70 were included for review. We were able to categorize environmental factors into housing security, home environment, and neighborhood environment, and, within each environmental category, specific elements/aspects are discussed. This paper provides a comprehensive map connecting identified levels of influence (individual, home/house, and neighborhood-level) in which subfactors are listed under each level of influence/category with the related literature list. Our review highlights that multidimensional environmental factors can affect aging adults’ sleep health and eventually their physical, mental, and cognitive health and that sleep disparities exist in racial minorities in socioeconomically disadvantaged communities in which cumulative environmental stressors coexist. Based on this focused narrative review on the multidimensional sleep environments for aging adults, knowledge gaps are identified, and future research directions are suggested. Full article

In this study, a system of discontinuous rigid blocks is employed to simulate the possible damage mechanisms in unreinforced masonry (URM) façades and load-bearing frame systems subjected to settlement using the discrete element method (DEM). First, the employed modeling strategy is validated utilizing the available experimental results presented in the literature. Once there is a good agreement between the computational models and experimental findings, a sensitivity analysis is performed to quantify the influence of the input parameters defined in the DEM-based numerical model. Finally, the proposed modeling strategy is further utilized to assess the damage pattern that may develop in a URM façade due to uniform and non-uniform settlement profiles. The results of this study clearly show that the discrete rigid block analysis (D-RBA) provides robust numerical solutions that can be employed to visualize and assess the possible damage patterns and related collapse mechanisms of URM masonry systems as an alternative modeling strategy to standard continuum-based solutions. Full article

This article presents the advantages and limitations of a recently developed Ultrasonic Guided Wave Leakage (UGWL) method in comparison to the well-known Half-Cell Potential (HCP) method in their ability to detect corrosion in reinforced concrete (RC) bridge decks. This research also establishes a correlation between UGWL data and chloride content in concrete RC slabs. Concrete slabs submerged in a 10% NaCl solution were monitored using both methods over a period of six months. The chloride content from the three cores (0.84, 0.55, and 0.18%) extracted from the slab after the 6-month long process all exceeded the chloride threshold values suggested in ACI 318, which is 0.05 to 0.1% by weight of concrete. Further, the UGWL method detected changes due to corrosion approximately 21 days earlier than the HCP method. Full article

The majority of architectural heritage consists of load-bearing masonry components made up of stone units and relatively weak mortar joints, yielding potential weak planes for masonry structures where tension and shear failures are expected to occur. Advanced nonlinear analyses are required to simulate these phenomena and predict the corresponding nonlinear structural behavior of historic masonry constructions. In this context, this paper presents a model of a stone masonry Roman aqueduct (the Valens Aqueduct), constructed in the fourth century A.D. in Istanbul, Turkey, to explore the seismic capacity and behavior using the discrete element method (DEM). The employed modeling approach comprises distinct rigid blocks interacting along their boundaries based on the point-contact hypothesis. Thus, the discontinuous stone skeleton of the masonry aqueduct is represented explicitly in the computational model. First, a validation study was conducted on the laboratory experiment to demonstrate the capabilities of the adopted modeling approach. Then, a discontinuum model representing the Valens Aqueduct was used to assess the seismic capacity of the structure under gradually increasing lateral forces. The numerical simulations gave insight into the structural response of the aqueduct from the elastic range to total collapse. Additionally, parametric research was performed considering joint properties, namely the joint tensile strength, contact stiffness, joint friction angle, and compressive strength of the masonry, to quantify the effects of contact parameters on the displacement response of the DEM model. Further inferences were made regarding the modeling parameters, and practical conclusions were derived. Full article

Nonhomogeneous material characteristics of masonry lead to complex fracture mechanisms, which require substantial analysis regarding the influence of masonry constituents. In this context, this study presents a discontinuum modeling strategy, based on the discrete element method, developed to investigate the tensile fracture mechanism of masonry wallettes parallel to the bed joints considering the inherent variation in the material properties. The applied numerical approach utilizes polyhedral blocks to represent masonry and integrate the equations of motion explicitly to compute nodal velocities for each block in the system. The mechanical interaction between the adjacent blocks is computed at the active contact points, where the contact stresses are calculated and updated based on the implemented contact constitutive models. In this research, different fracture mechanisms of masonry wallettes under tension are explored developing at the unit–mortar interface and/or within the units. The contact properties are determined based on certain statistical variations. Emphasis is given to the influence of the material properties on the fracture mechanism and capacity of the masonry assemblages. The results of the analysis reveal and quantify the importance of the contact properties for unit and unit–mortar interfaces (e.g., tensile strength, cohesion, and friction coefficient) in terms of capacity and corresponding fracture mechanism for masonry wallettes. Full article

This article presents the latest improvements in a recently developed nondestructive testing (NDT) approach for early detection of various flaws (corrosion, delamination, and concrete cracking) in reinforced concrete (RC) bridge decks. The proposed method involves the use of internal steel reinforcement as a wave guide for transmitting ultrasonic waves through the system and the measurement of leaked energy from the surface of the concrete. This paper builds upon the progress made in the previously published phases of the project and aims to further explore the capabilities and practicality of the proposed NDT method. Specifically, the limits of propagation distance, effect of bidirectional reinforcement, methods of attachment and coupling of the sensors to the reinforcement and concrete, and suggestions for optimal sensor arrays are discussed in this paper based on the findings from the most recent laboratory tests and pilot field tests. The results show that with careful placement of sensors and data interpretation, early stages of localized corrosion and delamination can be detected, even when bidirectional and multiple layers of reinforcement are present. For field applications, an angled seat made of fast-setting Hydrocal gypsum cement is recommended, and it is projected that the optimal angle of attachment is 33 degrees or less from the vertical axis. Full article

The use of fiber reinforcement in traditional concrete mixes has been extensively studied and has been slowly finding its regular use in practice. In contrast, opportunities for the use of fibers in masonry applications and structural rehabilitation projects (masonry and concrete structures) have not been as deeply investigated, where the base matrix may be a weaker cementitious mixture. This paper will summarize the findings of the author’s research over the past 10 years in these particular applications of fiber reinforced cements (FRC). For masonry, considering both mortar and mortar-unit bond characteristics, a 0.5% volume fraction of micro fibers in type N Portland cement lime mortar appear to be a viable recipe for most masonry joint applications both for clay and concrete units. In general, clay units perform better with high water content fiber reinforced mortar (FRM) while concrete masonry units (CMUs) perform better with drier mixtures, so 130% and 110% flow rates should be targeted, respectively. For earth block masonry applications, fibers’ benefits are observed in improving local damage and water pressure resistance. The FRC retrofit technique proposed for the rehabilitation of reinforced concrete two-way slabs has exceeded expectations in terms of capacity increase for a relatively low cost in comparison to the common but expensive fiber reinforced polymer applications. For all of these applications of fiber-reinforced cements, further research with larger data pools would lead to further optimization of fiber type, size, and amount. Full article