Tran-SET 2022

Till today, moisture is the arch-nemesis of asphalt pavements causing stripping, rutting, potholes, and fatigue cracking. Moisture-induced damage is quite common in places, which experience heavy rainfall along with shallow groundwater levels. All these phenomena result in a premature pavement failure seeding nuisance to many state DOTs. Early failure requires unexpected budget allocation to maintain the road condition up to the standards. Thus, this study utilized sessile drop (SD), Fourier transform infrared (FTIR) spectroscopy, and the Texas boiling test to evaluate the moisture susceptibility and chemical signature of binders recovered from asphalt mixtures. Four plant mixes HMA 308-20, HMA 221-21, SMA PMLC, and Bmit PMLC were collected to achieve these study goals. SD test showed that water had the highest contact angle compared to two other probe liquids. Contact angles were lowest for HMA 308-20 and highest for Bmit PMLC. Surface free energy (SFE) was highest for HMA 308-20 and lowest for Bmit PMLC. FTIR test showed that the Bmit sample had an exclusive strong C=O stretching resulting from acid/aldehyde. Texas boiling test showed that all mixes demonstrated a very good percentage of asphalt retention (>80%). Further laboratory-based tests on mixes and recovered binder will be conducted to develop a stripping and moisture damage resistant mix design.

Low density polyethylene (LDPE), high density polyethylene (HDPE), and polypropylene (PP) are some of the widely used plastic products around the world. As part of recycling, these plastics have been experimented to be utilized in the construction of pavements to offer an opportunity to mitigate environmental pollution. The objective of this study is to investigate if LDPE, HDPE, or PP modified asphalt binders can be identified using Fourier transform infrared (FTIR) spectroscopy. In this experiment, 3% and 9% of each of the three unused plastics flakes were added to asphalt binders using a high shear mixer. Additionally, two more grades of PP were used—industrial waste (IWPP) and solid waste (SWPP). The FTIR analysis was performed using the peak height method after performing a two-point method for index calculation. For LDPE and HDPE, the results indicate that these plastic-modified asphalt binders neither show any new peak nor show significant intensity difference in existing peaks in the spectra and hence cannot be identified. However, IWPP modified asphalt binder shows a new peak at 1,014 cm^–1 which is not present in any of the unmodified neat binders. Moreover, SWPP modified asphalt binder as well as pure PP modified asphalt binder show the presence of a new peak between 997 and 1,000 cm^–1. The height of the absorbance peak also increases with the change in PP percentage from 0% to 9% (R² = 0.891 for pure PP, R² = 0.950 for SWPP, and R² = 0.747 for IWPP). It is likely that the peak at 1,014 cm^–1 indicates the presence of siloxane, Si–O–Si stretching vibration, while the peak at 997 cm^–1indicates the isotactic polypropylene band functional group. The result of this study would help identify the presence of polypropylene in any asphalt binder with a handheld FTIR in a rapid, portable, and non-destructive technique.

Pavement performance data are a critical component of pavement management systems, and are affected many factors as the pavement structure, climate, traffic, and material properties. The current traditional “parametric” techniques still adopted by state agencies can hardly predict performance distress indices reliably and with high accuracy. Hence, the objective of this study was to employ a non-parametric machine learning algorithm to predict the pavement condition index (PCI) of asphalt concrete (AC) overlays on flexible pavement roads over a period of 11 years. In particular, the decision tree (DT) algorithm was examined. A total of 894 log miles from 50 control sections in Louisiana were included in the analysis. Six models were developed using as inputs; the pre-treatment PCI (before overlay application), the highway functional class, the overlay thickness, the overlay age, the cumulative annual truck traffic, the cumulative annual rainfall, and the mean annual temperature. Models yielded a fair accuracy in predicting PCI after 11 years.

Warm mix asphalt (WMA) can reduce the mixing and compaction temperatures by 16 to 55°C compared to hot mix asphalt (HMA). These considerable reductions in production temperatures result in lower fuel demand, a better workplace environment, and lesser emissions of greenhouse gases, etc. This study evaluated three Arkansas Department of Transportation (ARDOT)-approved performance grade (PG) binders: PG 64-22, PG 70-22, and PG 76-22 modified by four WMA additives: Sasobit, Advera, Evotherm, and Rediset. Penetration, rotational viscometer (RV), dynamic shear rheometer (DSR), Fourier transform infrared spectroscopy (FTIR), surface free energy (SFE), Texas boiling, and acid number (pH) tests were performed on these samples. The RV test results showed a slight reduction (up to 5 °C) in mixing and compaction temperatures for Sasobit, Evotherm, and Rediset modified binders. Binder samples modified by Sasobit and Advera showed improved rut resistance among all the samples. Both Evotherm and Rediset modification resulted in higher surface free energy compared to their corresponding unmodified binders. FTIR test results showed that Advera introduced sulfoxide (S=O) and hydroxyl (-OH) groups into base binders. Texas boiling test results showed that asphalt retention was high (>80%) for both Evotherm and Rediset modified samples. Acid number test results showed that both Advera and Rediset increased pH values of binder samples compared to their corresponding unmodified samples. These results will help the agencies and contractors choose the right WMA technology for asphalt paving projects.

The present study aims to develop and assess ultra-high-performance engineered cementitious composites (UHP-ECC) materials, made mostly from readily available ingredients in Louisiana, with rheological properties especially optimized for construction 3D printing (3DP). Mainly, this study evaluated the effect of fly ash to cement ratio (FA/C), sand to binder ratio (S/B), and high-range water reducer (HRWR) content on the fresh properties and compressive strength of the cementitious composites. Fresh properties evaluated in this study included flowability, setting time, extrudability, and shape stability. Furthermore, the compressive strength was performed at 28 days to assess hardened properties. Experimental results showed that (1) the increase in FA/C produced a decrease in f’c, but an increase in flowability and setting time; (2) an increase in S/B resulted in a decrease in flow and setting time, as well as an increase in shape stability; and (3) the increase in HRWR resulted in an increase in flow as expected.

This study assesses the effects of substrate surface preparation on ultra-high performance concrete (UHPC) overlay bond. Bond assessment is important because effectiveness of an overlay greatly depends on overlay-substrate bond. Bond was assessed by subjecting overlaid specimens with five substrate surface moisture conditions (excess free moisture, a thin layer of free moisture, air-dried saturated surface-dry (SSD), towel dried SSD, or dry) and five substrate surface textures (smooth and brush, light, medium, and heavy sandblasted) to direct tension and direct shear tests. All surface textures facilitated adequate shear strengths when there was free moisture on the surface. In general, bond strength improved with aggregate exposure as long as the substrate was visibly moist (SSD or wetter) at UHPC overlay placement. The primary conclusion was that visibly moist exposed aggregate surfaces facilitated acceptable bond [greater than 1.03 MPa (150 psi) for tension and 1.00 MPa (145 psi) for shear].

This study investigates the influence of using Portland limestone cement (PLC), also referred to as Type IL cement, as a complete substitution for ordinary Portland Cement Type I in engineered cementitious composites (ECC). ECC mixtures with two different replacement levels of ordinary Portland cement with PLC were produced (i.e., 0% and 100% by mass). In addition, both ECC mixtures were produced using fly ash as supplementary cementitious materials, sugarcane bagasse ash as fine sand, and polyvinyl alcohol fiber at a 1.5% volume fraction. The compressive strength of the produced ECC mixtures was evaluated at 28 days of curing. The setting time of each ECC mixture was evaluated by following the guidelines of ASTM C403. Experimental results demonstrated that the mixture using PLC as a binder improved the compressive strength by 7.16% compared to the mixture utilizing Portland cement. The setting time results indicated that PLC used as a binder decreased the initial setting time by 18.73% and decreased the final setting time by 11.59% compared to using Portland cement.

This study adopted the vacuum impregnation of bacteria into a lightweight aggregate (LWA) technique by using yeast extract as a nutrient, calcium lactate as a mineral precursor, and bacteria spores called Bacillus pseudofirmus as a healing agent. The impregnated lightweight aggregate was used in the concrete mixture to evaluate the effect of calcium lactate with bacteria on the mechanical properties of concrete and crack healing efficiency. In addition, a control sample was prepared without bacteria or precursors for comparison purposes. Three concrete cylinders and three concrete beams were prepared for each concrete mixture. The results showed that the concrete mixture with calcium lactate and Bacillus pseudofirmus bacteria (N + CaL + BP) significantly improved the flexural strength, compressive strength, and flexural strength recovery compared to the control sample. However, it did not significantly increase the self-healing efficiency (16.11% only increase in self-healing efficiency of side faces of N + CaL + BP compared to control).

The incorporation of supplementary cementitious materials (SCMs) in concrete can lower the carbon footprint and improve the durability performance. This research focused on studying the effects of different SCMs such as class F fly ash (FA), reclaimed fly ash (RFA), and ground bottom ash (GBA) on the long-term durability properties of concrete containing 10%, 20%, and 30% replacement levels. Long-term durability properties of concrete, including drying shrinkage and alkali-silica reactivity (ASR), were determined along with the workability (slump) and compressive strength. Experimental results showed that FA and RFA-modified concrete exhibited higher workability than GBA-modified concrete. However, GBA-modified concrete achieved the highest compressive strength at the 30% replacement level. Concrete modified by each SCM demonstrated lower drying shrinkage and ASR expansion than conventional concrete. Considering the overall performance of concrete (drying shrinkage, ASR, workability, and compressive strength), a 20% replacement level of all SCMs would be optimum content.

This study evaluated the influence of cellulose nanocrystal (CNC) addition on the compressive strength of engineered cementitious composites (ECC). CNC was added to ECC mixtures at 0.5, 1.0, 1.5, and 2.0 wt.% of cement. CNC was synthesized from rice husk following an acid hydrolysis process. Transmission electron microscope (TEM) and X-ray diffraction (XRD) were carried out to characterize CNC nanocrystals. A compression test was performed to analyze the properties of ECC mixtures. TEM results showed that the length of CNC was in the range of 76–150 nm. The XRD results also showed a 55% crystallinity index in the developed CNC. Moreover, the highest compressive strength of 43.1 MPa was obtained at 2.0 wt.% of CNC, which was higher than normal concrete strength, i.e., 30 MPa.

Ultrathin whitetoppings correspond to a rehabilitation technique that consists of placing a layer of concrete on top of distressed asphalt pavements. Due to its satisfactory results, different performance prediction models were developed for this type of infrastructure. Even though concrete has displayed satisfactory results for UTWs applications in the past, several distresses have been associated with them due to the brittle nature of concrete. To overcome this issue, a high ductility material known as engineered cementitious composites (ECC) was proposed for UTWs. The present study developed an initial performance prediction model by implementing finite element analysis that considers the plastic properties of ECC along with two bonding conditions with the asphalt layer (i.e., fully bonded and unbonded). Different ECC layer thicknesses were modeled, ranging from 50.8 to 101.6 mm, and the critical stresses for each thickness were determined. Finally, critical stress vs. thickness curves were plotted for each bonding condition. From these curves, the critical strength and thickness responsible for triggering the plastic regime for ECC-UTWs were determined (i.e., 3.35 MPa and 69.8 mm, respectively).

3D concrete printing is a cutting-edge construction technique that has the potential to revolutionize the construction industry due to cost saving in terms of labor and formwork costs, efficiency in construction, lower safety-related risks, and a higher degree of automation. However, several issues still make its adoption relatively slower on a large scale. Engineered cementitious composites (ECC), a class of ultra-high-strength concrete, can be a potential solution to some of the problems currently faced by 3D concrete printing, such as reinforcement and durability. This study is a preliminary phase of a Tran-SET project focusing on the design of 3D printable ECC, considering the concrete mix design proportions and their potential effects on fresh and hardened properties to achieve an optimized, printable ECC mix. The type and content of various concrete ingredients such as cement, admixtures, aggregates, and fibers have considerable influence on the several properties in the fresh and hardened state. The investigation was done to evaluate the effect of some critical parameters of mix design proportioning, including the contents of mineral admixtures, such as fly ash, slag, metakaolin, nano-clay, silica fume, chemical admixtures, (superplasticizer), fine aggregate, and fibers. The replacement levels were 0%, 50%, and 75% for mineral admixture; 10% for silica fume; and 0.4% for nano-clay by cement mass. Locally available fine aggregates were also used at 25% and 40% by mass of binder. In addition, the influence of fiber types and contents was also investigated. Two types of fibers, polyethylene (PE) and polyvinyl alcohol (PVA) fibers, were used at different levels, such as 0%, 1%, 1.5%, and 2% of the total volume of the mix. The flowability of the ECC mixes was reduced with the incorporation of slag, metakaolin, higher aggregate content, and PE fibers. The high contents of both PVA and PE fibers (2%) (50.46 and 56.39 MPa) depicted a reduction in compressive strength as compared to the low fiber content. Moreover, the PE-ECC exhibited superior tensile ductility as compared to the PVA-ECC due to the more fiber bridging by the PE fibers at the crack interface.

Electronic ticketing (e-Ticketing) technology has not been widely adopted by the highway construction sector for a variety of reasons, including stakeholders’ opposition and technological challenges. Numerous studies have touted its benefits; however, few states have taken the initiative to implement and mandate statewide use of the technology. The goal of this study is to determine the key factors that are preventing the implementation of e-Ticketing technology and to propose appropriate strategies to overcome them. Seven critical limitations that adversely affect its implementation were identified through a thorough review of existing literature, and a survey questionnaire was designed and distributed to key stakeholders in the technology adoption process such as state departments of transportation (DOTs), general contractors, and material suppliers. A statistical analysis of the survey data revealed that problems encountered during the bidding process and the drawing up of agreements, training of employees, and lack of stakeholder support significantly impact the e-Ticketing technology implementation. In addition, the authors provided practitioners with potential strategies for their consideration when pilot testing and implementing e-Ticketing. The results of this study will aid state DOTs in selecting the most effective e-Ticketing software for pilot testing and will help them overcome obstacles encountered by their predecessors.

The evolution of technology and the use of mobile devices for performing daily operations has benefited the construction industry. E-Ticketing can automate most administrative processes in highway construction, provide valuable insights into daily operations, and increase inspector safety. Many state departments of transportation (DOTs) have conducted pilot testing of the technology and have opted not to install or acquire it for a variety of reasons, and a few have discontinued their pilot studies. Thus, the goal of this research is to identify and pinpoint the misconceptions surrounding the implementation of e-Ticketing platform and to explore ways to make it attractive to more users. To achieve this, an extensive literature review was conducted of studies that investigated the implementation of technology. Then, semi-structured interviews were held with 13 individuals who are employed in the highway construction industry. Inductive thematic analysis of the interview transcripts revealed two primary causes for the delays in implementing the technology: (1) a misunderstanding resulting from the limited implementation of the platform during COVID-19; and (2) a high initial investment cost for state DOTs because of overlapping fleet management functionalities. This research will help DOT decision-makers and engineers in re-define the functionalities of the e-Ticketing platform, adopt regulations and standards, minimize project costs, provide initial funding, performing pilot testing, and enhance inspector safety.

Construction sector encounters highest workplace accidents. The hazardous nature of construction worksites cannot be eliminated, but efforts can be taken to reduce the workplace accidents through improved safety practices. Ignoring the unsafe behavior and practices in workplace leads to increase in workplace injuries and mortalities. Outdoor occupation has experienced increased mortality rates due to compromised attention on workers’ health and safety practices. Incidence of mortalities due to respiratory issues have been on the rise during hot weather conditions. Performing in hot temperatures can further trigger various other health ailments such as heat cramps, heat exhaustion, heat edema, and mental health issues. The aim of this study is to identify the effects of hot weather on construction workers’ health and to develop a predictive model on workers’ respiratory issues based on various demographic factors. To achieve this, a questionnaire survey was developed and distributed to workers in construction industry. The results of the survey revealed that the effects of temperature on workers’ health is not uniform and varies based on attributes such as gender and type of construction sector. The outcomes of this study will help project managers and safety professionals to develop preventive measures for workers performing in extreme temperatures.

In this study, genetic algorithm (GA) was employed to model the degradation of thermoplastic markings considering the key variables that are believed to have a significant effect on marking performance. A total of 4,608 skip retroreflectivity measurements were collected from three NTPEP test decks in Florida, and 12 predictive models were developed using GA. Apart from other key inputs, the first model was developed using the initially measured skip retroreflectivity, while remaining models used predicted values from the previous models. The developed GA models demonstrated an acceptable level of accuracy in terms of coefficient of determination (R²) and root mean square error (RMSE). The models predicted skip retroreflectivity of the thermoplastic markings for up to 1 year using only the initial measured skip retroreflectivity, which could assist transportation agencies to determine the expected service life of a marking product based on a specified retroreflectivity threshold and plan for future restriping activities.

State departments of transportation (DOTs) are constructing and managing more highway projects than ever before despite limited funds and a shortage of inspectors. A few DOTs and general contractors have implemented e-Ticketing technology to increase their workforce productivity and efficiency, but the majority are still using conventional paper methods because they do not fully comprehend the benefits of the technology. The goal of this study is to quantify the impact of e-Ticketing technology on the number of inspectors required for a project and on the level of productivity. A comprehensive literature review and stakeholder survey were conducted and revealed that all 20 DOTs reported workforce shortages. A comparison was made between the required number of inspectors prior to and after the implementation of e-Ticketing, and it was found that projects requiring multiple inspectors could reduce their workforce by 25% by implementing e-Ticketing. The findings of this research will enable state DOTs to reduce the number of inspectors on-site, thereby circumventing the shortage of workers.

Surface stress sensitive film (S₃F) is a new technique for measurement of shear and normal stresses. Using such innovative sensor in geotechnical engineering applications could accurately measure the interfacial friction between the structure and surrounding soil, which is crucial to understand the soil-structure interaction of various buried civil structures. In this study, a method for the shear stress calibration of the S₃F sensor was proposed. The effect of the loading area on the shear stress calibration curves was investigated. And the performance of the sensor in measuring the shear stresses at the soil-structure interface was assessed. The test’s result revealed that the slope of the shear stress calibration curve is independent from the diameter of the loading area. The S₃F sensor also showed its ability to measure shear stresses under loading/unloading conditions, as long as the applied shear stress is less than the yielding stress of the S₃F film.

Construction costs can increase dramatically when soft and/or expansive clay is found on site. Replacing undesirable soil with more stable soil is widely practiced in many countries. The present study has focused on stabilizing poor-quality soils in Arkansas by using rice husk ash (RHA), which is agricultural waste. A commonly used stabilizing agent, hydrated lime (HL), has also been evaluated for comparison purposes. The main objective of this study is to determine the optimum percentages of RHA and HL that can stabilize the tested soil. The sample has been collected from an ongoing construction project from I-555 near Jonesboro, Arkansas. It is clay soil (CL) with low plasticity (AASHTO type A-6). The unmodified (control) and modified soils with varying dosages of RHA (3%, 6%, and 9% by weight) and HL (1%, 3%, and 5% by weight) were evaluated in the laboratory. The unmodified and modified soils are then subjected to the Atterberg limit test, modified Proctor test, pH test, and unconfined compression strength test (UCS). The UCS test was conducted with remolded specimens for seven days of curing. It was found that the liquid limit of the soil increased by 15% and 24% with the addition of 9% RHA and 5% HL, respectively. There was a great reduction in the maximum dry unit weight by 13% and 9% at 9% RHA and 5% HL, respectively. The RHA showed a slight increase in the pH of the soil to reach pH 7.75 at 9% RHA, while the pH increased dramatically by using 5% HL to reach pH 12.95. RHA showed a good amount of reduction for the soil volume change from 20% to 6% at 9% RHA. A 5% HL hydrated lime showed a reduction in the soil volume from 20% to 10%. The unconfined compressive strength increased to reach 381 and 208 psi with 9% RHA and 3% HL, respectively. Based on limited test results, 6% RHA and 3% HL are found to be the optimum dosages to improve the properties of tested soil. The findings of this research have the potential to significantly benefit the construction industry in Arkansas by reducing costs associated with traditional methods of soil stabilization.

Traffic signal recognition is a core task in autonomous driving. In this paper, an end-to-end, real-time deep learning object detection algorithm called YOLO (you only look once) is adopted for traffic signal recognition applications. Two separate open-source image data sets were used for training signal detection models for day and night-time traffic scenarios, respectively. Since the default YOLO framework offers real-time detection, focus was given on achieving acceptable levels of detection accuracy through improving data quality for training. First, the training data sets were cleansed of existing ground truth annotation errors and irregularities. Second, by applying mosaic image augmentation, stitching four randomly upscaled images together, twice during the model training, overall detection accuracy was further improved.

In this study, a rapid (<45 min including analysis of results) and mildly invasive method was developed to extract a small amount of asphalt mixture (<20 gm) from an in-service road and perform the Fourier-transform infrared (FTIR) spectrometer analysis to determine its degree of oxidative aging. A handheld attenuated total reflectance (ATR) FTIR spectrometer was used as the primary equipment to investigate the carbonyl index (CI) values of six different roads in northern Louisiana. The CI value was calculated as the ratio of the peak height of the carbonyl functional group at 1,695 cm^–1 and the aliphatic functional group at 2,920 cm^–1. Three small half-inch diameter cores were made on each of the roads with a hand drill to collect the sample, while dichloromethane (DCM) was used as the quick extraction solvent. The result showed that the CI values changed from 4.79% to 10.95% for the six in-service roads, while the average CI of three different original binders from multiple sources was found to be 3.04%. It was found that the CI value of a road depends significantly on its service age, the intensity of sunlight during the daytime, and the annual average daily traffic (AADT) loading. The CI value was found higher for the roads having high service age, high AADT loading, and high ultraviolet (UV) radiation exposure. It was also found that the extracted asphalt binder on the no-loading area (which is just outside the white line) of a road encounters less aging compared to the main wheel pathway. The gradual increase in CI values with the increase in service age validates the efficacy of this method. The study will help to understand different influential factors for oxidative field aging as well as develop a rapid and reliable in situ method to investigate the aging of different service roads.

Ultra-high-performance concrete (UHPC) is an emerging construction material with exceptional mechanical and durability properties. Silica fume has been used in UHPC as the main supplementary cementitious material (SCM) to improve mechanical and durability properties. However, silica fume is more expensive than cement and other SCMs, so it is often replaced with class F fly ash. Unfortunately, future availability of fly ash is uncertain because the energy industry has been removing coal burning generating stations from operation creating a need to find new, cost-effective, and environmentally friendly alternatives to fly ash. This study assessed use of metakaolin and a natural pozzolan (pumicite) as potential replacements for fly ash and silica fume in UHPC mixtures. Results from workability, compressive strength, and flexural strength tests indicated that replacing up to 75% of the fly ash in a control mixture with pumicite as well as replacing 100% of the fly ash and 25% of the silica fume in the control mixture with metakaolin led to acceptable 28-day compressive strengths [greater than 17,000 psi (120 MPa)]. Compressive and flexural strengths of UHPC mixtures decreased with increasing pumicite and metakaolin content, although strengths remained above 17,000 psi (120 MPa).

The surface deflection bowl data collected through falling weight deflectometer (FWD) has been widely utilized by various department of transportation (DOTs) in the south-central states and other places. However, a robust method to evaluate pavement sections utilizing FWD data from all the sensors is seldom developed. There is always a need for DOTs and highway agencies to have a simplified procedure, which can be directly implemented in agencies’ databases. This study focuses on expanding and validating the concept of previously developed area ratio parameters towards the pavement section of south-central states (Arkansas, Louisiana, New Mexico, Oklahoma, and Texas) in effectively analyzing the pavement performances. Simulation-based deflections are utilized to develop enhanced deflection-based parameters and to reduce the need for extensive FWD testing in the field. Ninety-seven pavement sections in these states are considered to implement and validate simplified procedures that will be readily available to various transportation agencies to evaluate their pavement conditions at the network level. Eventually, a pavement ranking chart is proposed for the five south-central states, which categorizes the pavement section into very good, good, fair, and poor pavement sections.

Adoption of technology and digitization have proven to be effective methods for construction inspection and material delivery. Despite the fact that various technologies are available to bolster construction inspection and material delivery, there is a dearth of knowledge on effective utilization of mobile technologies for highway construction. The purpose of this paper is to evaluate the e-Ticketing technology in terms of its advantages and to identify key integrations that will enhance its usefulness. A survey was conducted to determine highway construction stakeholders’ opinions on benefits and future integration of e-Ticketing technology. Based on the 53 responses collected from various state DOTs, the study ranked the benefits of e-Ticketing implementation and suggested additional integrations as well. The primary integrations and additional developments for the e-Ticketing platform are automated delivery/dispatch alerts, formattable inspection checklists, fleet management, sensors for temperature monitoring (IR pavers), and as-built drawings/digital blueprints. This study contributes to the existing body of knowledge by examining the opportunities for state DOTs to improve workforce productivity, increase workforce safety and morale, minimize schedule delays, and be prepared for the next pandemic if any.

Thousands of workers in the construction of coal mining projects are exposed to hazardous mine gases, chemical discharges, unfavorable climatic and environmental conditions, and other dangers. Therefore, it is necessary to develop preventive strategies that benefit workers to prepare for disasters and overcome hazards when working in mining operations. The goal of this research is to determine, rank, and weight the preventive action by utilizing the Delphi approach. First, 43 preventive strategies were identified through a thorough literature review. Next, eight mining industry professionals were invited to participate in the Delphi method, and 10 preventive methods were identified, selected, and weighted through two rounds of the Delphi survey. Using a calibrated gas monitor to detect dangerous and toxic gases before entering and working in confined spaces, employing proper personal protective equipment (PPE) to prevent electrical hazards due to arc flash, and establishing an emergency communications system to provide warnings are the three most effective preventive measures. This study’s findings will aid policymakers in adopting the identified strategies for reducing mining hazards.

Cold weather conditions create serious safety and health hazards in outdoor working populations. Construction sector is highly streamlined toward outdoor activities. Laborers involved in construction sector are often exposed to extreme weather events, risking their health and safety. Worker productivity decreases, exposed individuals are at risk of developing several health problems, and workplace injuries and workplace safety are compromised. This creates a need to explore the various health problems and safety issues experienced by outdoor construction workers. A predictive model that can identify workers who are more susceptible to various health issues caused in cold environment has to be developed to identify and protect workers at risk. Toward this goal, a thorough literature review was conducted to identify the potential health challenges followed by developing a questionnaire survey. The survey distribution yielded 100 responses in total. The gathered data was used to analyze the health, safety challenges experienced by construction workers and to predict susceptible workers in cold weather conditions by taking various demographic factors into consideration. The results of the study revealed that the construction workers experiencing cold weather injuries like freezing of body parts varied based on demographic factors such as gender, ethnicity, and type of sector the workers are involved in. Respiratory issues, which are one of the most common problems during cold weather, varied with gender and work environment. The results obtained will help professionals and senior associates in construction area to develop preventive measures for workers performing in cold weather.

One out of every 5 miles of highways and 45,000 bridges in the United States are in poor condition. Transportation agencies and highway construction industries are significantly impacted by workforce shortage, quality issues, and schedule delays for decades. For almost two decades, the industry has been facing the same obstacles, and it is high time that these problems are addressed with research, innovation, and implementation. This study’s objectives are to (1) identify the various inefficiencies in material delivery, ticketing, and inspection processes; (2) rank the challenges to analyze their impact; and (3) identify proven technologies that can mitigate the encountered challenges. The study involved a comprehensive review of literature before distributing a survey questionnaire to 20 state departments of transportation (DOTs). Using the Relative Importance Index (RII), the authors have ranked the operational challenges in highway construction. According to the findings of the study, the primary challenge in highway construction is the shortage of field engineers and inspectors. This research will encourage state DOTs to implement digital delivery and inspection technologies. Utilizing electronic ticketing and electronic inspection will eliminate some of the challenges and assist in mitigating the rest.

Extreme hot temperatures are considered as occupational hazard. Workers performing for a longer duration in extreme heat are prone to develop various health complications. This is also indicated by increasing number of heat related morbidities and mortalities. Workers exposed to extreme temperatures experience serious health issues like heat cramps, heat edema, and mental health problems like depression. Workers are distracted when performing in extreme temperatures leading to workplace accidents, injuries, and lowers productivity. Health challenges experienced by workers differ based on demographic characteristics, and thus construction sites require strategies tailored to address these vulnerable workers. Therefore, this study focuses to assess workers’ health challenges based on various demographic features and develops a model for physical fatigue, workplace injuries of workers performing in extreme temperatures through an online survey questionnaire. Logistic regression was performed on the gathered data. The results revealed that Caucasians are more susceptible to adverse effects of hot weather compared to other ethnicities. A link can be suggested, based on the results of the study, among workers’ physical exhaustion and type of working environment, and ethnicity of workers in hot weather conditions. The findings of the study will facilitate professionals in construction industry to improve their heat related policies.

Texas has more than 55,000 bridges, where more than 50% of the bridges are over 40 years old, approaching their design life span with increasing maintenance and rehabilitation needs. Despite the ever-increasing traffic demand due to population increase and urbanization, bridge assets are also exposed to more intense environmental threats due to climate change, degrading their structural condition and traffic carrying functionality. This study examines the climate change impacts on the deterioration of transportation infrastructure, particularly concrete highway bridges in Texas. Mechanics-based reinforced concrete deterioration models are coupled with state-of-the-art climate change forecasts to study the influence of climate change on the deterioration of concrete highway bridges. Sensitivity analyses are conducted via Monte-Carlo simulation to quantify time-dependent carbonation and chloride-induced corrosion damage risks in three representative locations (i.e., Houston, Dallas, and Amarillo) in Texas. The findings can better inform decision-making for climate adaptation in bridge asset management.

The interaction of seismically active New Madrid Seismic Zone (NMSZ) and Mississippi Embayment (ME) in Northeast Arkansas (NEA) has a greater chance of liquefaction in the region. Structures like bridges are vulnerable to the liquefaction phenomenon. So, the cone penetration test (CPT) data of 52 sites located within Mississippi County have been used for liquefaction vulnerability assessments using Cliq V.3.4.1.4 software. The values of peak ground acceleration (PGA) and moment magnitude of the earthquake (MM), required for liquefaction assessment, have been obtained from different site-specific ground motion response (SSGMR) analyses. The liquefaction analysis gives liquefied layers for foundation depths to be considered against and values of liquefaction potential indices that illustrate the relative vulnerability of liquefaction during sufficient earthquake triggering. Liquefaction hazard maps based on one of the liquefaction potential indices, liquefaction potential index (LPI), have been generated using the ArcGIS Pro tool that shows the spatial distribution of extent of risk due to cyclic liquefaction. These hazard maps can help to identify the vulnerable regions that may cause damage, mostly to bridges within Mississippi County in NEA, which can be used by the Arkansas Department of Transportation (ARDOT).

The thousands of workers employed by the United States coal mining industry are subjected to health and safety risks that can result in their being severely or even fatally injured. They are exposed to toxic mine gases, chemical releases, adverse climatic and environmental conditions, and other hazards that need to be managed by implementing adequate technologies and practices. The primary goal of the research was to identify the major categories of the hazards, detail their causes, and determine the measures that would be most effective at preventing them. A thorough review was performed of the data and information from the Centers for Disease Control and Prevention (CDC), Mine Safety and Health Administration (MSHA), numerous other journals, and conference papers, and four categories of hazards were determined as being major threats to miners: explosions, fires, inundations, and ground failures. A rigorous literature search was conducted on these hazards, resulting in various causes and preventative and constructive measures being identified and the glaring need for training coal miners on safe work practices becoming apparent. This research will enhance the understanding of the causes of coal mine hazards and provide preventative and constructive measures for managing them.

In this study, the effect of steel fiber and limestone powder on the fresh and hardened properties of 3D printable concrete was investigated. Mixtures were prepared using steel fibers (0.2 mm in diameter and 13 mm long) at three different fiber dosages (i.e., 0%, 1%, and 2% by volume). Fresh properties including extrudability and shape stability were evaluated. On the other hand, hardened properties assessed were the compressive strength (of mold-cast specimens) and flexural strength (of 3D printed specimens) after 7 days of curing. Experimental results revealed that the addition of steel fiber or limestone powder reduced the shape stability of printing mixtures, resulting in larger layer deformations. However, both compressive and flexural strength was significantly improved due to the addition of steel fiber, and the positive impact was more prominent at higher steel fiber dosages.

Railway earthworks provide a static platform for the track substructure. When constructing any railway structure with codified design resistance, earthwork layers of certain thicknesses and modulus of deformation need to be installed. The main objective of this study is to evaluate the deformation and strength characteristics of embankment soil by using the load-settlement curves. In this research, the Static Plate Loading Test, as per Indian Standard (IS) 1888, has been followed to obtain the stain modulus (E_v) of earthworks. An effort has been made by the researcher to utilize the railway earthworks including embankment, subgrade, and sub-ballast layers, which are categorized as sand and gravelly soil, sandy soil, and composite materials, respectively. The EV₂ values of these layers are found to be 71.2, 119.6, and 183.1 MN/m², respectively. The outcomes of this study are expected to help construction engineers in regulating the compaction quality for railway earthworks.

This study investigates the fresh (i.e., workability) and hardened (i.e., compressive strength) properties of metakaolin and class F fly ash (MKFA) based geopolymer (GP) mortars cured at room temperature. The qualitative and quantitative workability results for the MKFA GP mortars revealed that incrementing water to GP_solids (W/S) ratio and fly ash content leads to an increase in workability. However, in the case of compressive strength and density, increasing the W/S ratio and fly ash content increased the porosity, thus reducing the compressive strength. The increase in the porosity can be attributed to the delayed geopolymerization reaction due to the silica in fly ash being less reactive than in metakaolin. Moreover, MK₅₀FA₅₀ K(2.79)21-45%RS is a very workable material with a flow spread diameter of 180.38 mm, exhibiting the highest compressive strength and density of 10.81 MPa and 1.86 g/cm³. For future research, it is recommended to study different methods to enhance the compressive strength of MK₅₀FA₅₀ K(2.79)21-45%RS.

Sanitary sewer pipes make up a large portion of the nation’s buried infrastructure. New inspection technologies such as LiDAR have recently been employed for rapid condition assessment of RCSSPs. LiDAR inspection data can be used to quantify concrete wall erosion and subsequently assess their condition as opposed to the conventional qualitative evaluation. The current study investigates the effect of different zones across the pipe circumference on determining wall erosion for an inspected pipe using three different assessment methods. The results show that there are statistically significant relationships between the mean concrete erosion of different cases. In addition, the underlying erosion behavior of the 60^o–120^o sector of pipe is different from other cases. Results of this paper seek to enhance the knowledge of condition assessment of RCSSPs and pave the way for integrating the raw inspection data into rapid assessment tools for RCSSPs.