Construction operations are hazardous, leading to thousands of accidents, injuries, and fatalities annually. Safety risk assessment (SRA) is a key component necessary to respond to hazards effectively. Individuals have different perceptions of the riskiness of construction hazards, and studies have shown that different sociodemographic factors among employees can alter their SRA skills. However, their role in the US construction industry has been understudied, and this analysis investigates this topic further. Following a detailed systematic review of the relevant literature, quantitative data were collected from 181 construction fieldworkers in the United States using images integrated into an interactive questionnaire survey. Responses on the severity and frequency of seven potential accident causes were captured and analyzed. Findings from the literature review revealed six key sociodemographic factors—age, education, training, gender, ethnicity, and work type—that could impact fieldworkers’ SRA. However, a quantitative analysis suggests that only education is a significant influence, and sociodemographic factors had a statistically significant impact on less than five percent of the assessments. Therefore, the present study proposes that future investigation within the SRA domain should complement sociodemographic factors with critical behavioral factors that are rarely discussed, such as cognitive biases, personality traits, and safety behavior. As a foundational study for safety researchers and practitioners, the results provide information on SRA that can help enhance the safety and workforce sustainability of construction companies with a diverse workforce.

Seashells have been explored as a partial replacement for cement in cementitious matrices to promote sustainable waste management and decrease the carbon footprint associated with cement production. As research in this area expands, it is essential to synthesize current findings and practices to guide future studies on the feasibility of using seashells as a filler. This study analyzed existing research on using seashells as a partial cement replacement in cementitious composites through a systematic literature review conducted across six scientific databases, yielding 44 studies for data analysis and synthesis. Key findings identified the shell processing methods, established typical ranges for shell powder’s physical–chemical properties and dosage, and quantified the impact on mechanical properties in binary mixtures. The reported effects on mechanical properties varied among studies, potentially due to differences in processing techniques and the origins of the shells. Most improvements in composite properties were observed with 5% to 15% cement replacement in binary mixtures. Overall, incorporating shell powder reduces the carbon emissions of the produced composites. Further detailed investigations into shell processing variables and dosages are recommended to better understand how these factors influence the properties of the composites produced.

Service-life modeling of concrete structures exposed to chlorides has received increasing attention in recent years. Despite developments in understanding the transport phenomenon, most models still have limitations, and their results should be interpreted cautiously. This paper presents a state-of-the-art review of recent advances in time-variant models of surface chloride concentration (C_s) used as a boundary condition in service-life models, examining the role that boundary conditions can play in service-life estimates. Moreover, an overview of the root causes of variability in experimental results and a critical review of the strengths and limitations of time-variant C_s is provided. The results of numerical studies show that the time-variant boundary conditions considered in this work performed reasonably well with short-term empirical data and matched well with field observations. However, this review highlights the need for long-term field data to validate the performance and reliability of results obtained from service-life models using time-variant boundary conditions.

Introduction: Improper disposal of mollusk shells has led to environmental issues worldwide. Given their primary composition of calcium carbonate, these shells have been studied for their potential use as aggregate in cement composites, offering an environmentally appropriate destination for the waste and reducing virgin raw material use. However, there is a lack of research on the application of Sururu (Mytella falcata) shells, a species of mollusk commonly fished in countries such as Brazil. This study investigated the effects of Sururu shells waste from a Brazilian region on the mechanical and physical properties of mortar when partially replacing natural fine aggregate.Methods: Three mortar mixtures were produced, replacing 10, 20, and 40% of natural sand with Sururu shell aggregate (SSA) by mass. The specimens underwent consistency and density tests in their fresh state, and compressive strength, dynamic modulus of elasticity, and capillary absorption tests in their hardened state.Results: The results showed that workability decreased with the increase in SSA replacement, resulting in a reduction of 31.5% in consistency at 40% SSA replacement level. Compressive strength also decreased with SSA incorporation, but all samples continued to gain strength after 28 days, with 10% SSA samples showing only a 2.7% reduction compared to the control specimens. The dynamic modulus of elasticity was minimally impacted at 10% SSA, but significantly reduced at higher levels. Notably, SSA reduced capillary absorption in samples after 24, 48, and 72 h, indicating potential benefits in moisture management.Discussion: It was concluded that replacing 10% of natural sand with SSA was the most suitable option, considering the investigated mechanical properties of the mortar produced with SSA. However, further research is recommended to examine the durability and environmental impact of this solution.