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The filter paper (FP) method, a cost-effective, versatile, and convenient approach, has found extensive application in analyzing fine-grained soils, enabling the successful measurement of a broad spectrum of total and matric suctions. However, using the FP method in sand with a limited range of suction profiles has been notably underrepresented in the existing literature. Therefore, this study investigated the applicability of the contact FP method in establishing soil water retention curves (SWRCs) using five distinct FP calibration curves for 10 poorly graded sands. Among these calibration curves, the one presented by Chandler yielded the highest suction values, which were followed by those of ASTM. Furthermore, the FP results were subjected to fitting with a mathmatical model, which led to the observation that the overall trends in the obtained SWRCs displayed smooth sigmoidal shapes, resulting in a complete and coherent SWRCs. The SWRC results of five sand samples were assessed through validation against the hanging column technique (HCT) results, indicating a high degree of concordance and affirming the suitability of the FP method for sands characterized by a limited suction profile. Notably, the entire range of suction values fell within the 0.01–20 kPa range based on the calibration curves presented by Chandler and ASTM for all the examined sand samples, except sands 9 and 10. Furthermore, the suction values were unobtainable using the two aforementioned calibration curves within the ranges of 0.01–1.47 kPa and 0.01–0.172 kPa. [ABSTRACT FROM AUTHOR]

Cement stabilization is a widely applied technique in improving the workability and geotechnical properties of soft clay. This paper investigated the influence of cement stabilization on the soil–water characteristic curve (SWCC) and the deformation behavior of unsaturated cement–stabilized soft clay. The combined effect of cementation and partial saturation on the hydromechanical behavior of cement-stabilized soils was discussed. The SWCC of stabilized soil was measured in the full suction range under drying and wetting paths using the pressure plate method, the filter paper method, and the vapor equilibrium technique. The deformation behaviors of cement-stabilized soft soil were investigated by conducting suction-controlled oedometer tests. Furthermore, scanning electron microscope micrographs and mercury intrusion porosimetry tests were performed to investigate the effects of cement content on the evolution of soil pore structures. The test results showed that the water retention capacity of the stabilized soft clay increased with increasing cement content. The SWCC showed a significant hysteretic behavior in the boundary effect zone and transition zone, whereas the hysteretic effect was unapparent in the residual zone. The increased cement content had a more significant hysteretic effect on the SWCC. The deformation resistance capacity increased as the cement content and matric suction increased. However, the effect of matric suction on deformation resistance capacity decreased as the cement content increased. With the increase in cement content, the macropores were converted to small interaggregate pores, the pore spaces were distributed more uniformly, and the particle surface became rougher, resulting in higher water retention capacity and significant hysteresis of the SWCC. [ABSTRACT FROM AUTHOR]

This article discusses the importance of reproducibility in academic research, specifically in the field of bridge engineering. The authors argue that reproducibility is challenging due to factors such as paper documentation, technology constraints, and proprietary issues. They propose implementing a policy that encourages researchers to make their data and models available to others, although they acknowledge that full reproducibility may not always be practical. To incentivize this practice, the Journal of Bridge Engineering plans to introduce a visible recognition badge for papers that provide open data, models, and codes. The authors also outline the review process for papers seeking the "Data Verified Paper" designation. [Extracted from the article]

Natural pozzolans are defined as either raw (volcanic material, limestone) or calcined natural materials (burnt shale, calcined kaolinite) with pozzolanic properties. Historically, they are among the oldest materials that have been used in combination with lime for construction purposes. For example, Santorin earth is a natural pozzolan from a volcanic eruption around 1500 BCE on an island of the same name in Greece. Over the last decades, research into cement matrices has been changing direction, owing to deeper environmental concerns over the impact of the cement industry and its consequences for climate change. Global environmental policies are increasingly strict, prioritizing the re-use rather than the disposal of industrial wastes. In this context, one of the biggest challenges is the search for strategies that promote the industrial rotation of high volumes of wastes in their productive cycles. The main purpose of this research is to widen the existing knowledge base on the behavior of new mineral pozzolans of high added value in the cement sector, lending special attention to paper sludge wastes generated in the process of paper manufacture, in which recycled paper is used as a raw material. The results to date show that, once thermally activated (in the range of 650-700[degrees]C), paper sludge turns out to be an alternative source of recycled metakaolin. This product is characterized by its high pozzolanic activity and improved performance with regard to the benefits of certain binary cements. The possibility of incorporating this industrial waste in cements along with other already standard pozzolans focuses, as mentioned, on the notable increase in the production of these types of cements. This is due, at present, to the extensive constructive applications for type-II cements (single additive) and to their lower economic and energetic costs that also makes them more suitable in times of economic crisis. In the present paper, the influence that pozzolan blends (activated paper sludge and fly ash) have on the reaction kinetics of ternary blended cements (6 and 21% of replacement) is evaluated, paying special attention to the identification and evolution of hydrated phases with increasing reaction times. The results obtained represent a pioneering research line at a global level and represent a starting point for future investigations because in the case of using paper sludge, release of C[O.sub.2] from organic matter is very low and is listed as zero release. DOI: 10.1061/(ASCE)MT.1943-5533.0001223. Author keywords: Waste; Activated paper sludge; Fly ash; Blended cement; Pozzolans; Cements.

Forum papers are thought-provoking opinion pieces or essays founded in fact, sometimes containing speculation, on a civil engineering topic of general interest and relevance to the readership of the journal. The views expressed in this Forum article do not necessarily reflect the views of ASCE or the Editorial Board of the journal. [ABSTRACT FROM AUTHOR]

Distributed solar generation (DSG) has been growing over the previous years because of its numerous advantages of being sustainable, flexible, reliable, and increasingly affordable. DSG is a broad and multidisciplinary research field because it relates to various fields in engineering, social sciences, economics, public policy, and others. Developing a holistic understanding of the state of research related to DSG can be difficult. Motivated to provide that understanding, the goal of this paper is to explore current and emerging multidisciplinary research trends associated with DSG. To achieve that, (1) a large data set of approximately 66,000 publications was collected; (2) the papers were labeled using keywords for topics including "Batteries and Storage," "Solar," "Complex Modeling," "Machine Learning (ML) and Artificial Intelligence (AI)," "Resilience, Vulnerability, and Disasters," "Policies and Incentives," "Social Aspects," "Economics," "Smart Grid," "Finance," "Social Equity," "Microgrid," and "Virtual Power Plant"; and (3) the data set was analyzed using scientometric and social network analysis (SNA) in respect to publication counts, citation counts, and interconnectivity between the topics. Notable findings were analyzed to describe current and emerging trends. It was found that social equity has high citation counts contrasted by few publications, indicating a possible strong need for research. There is also rapidly growing research in ML and AI in the context of DSG during recent years. Other research topics, such as smart grids, have been attracting fewer publications. The results also highlight the need for multidisciplinary research connecting the topics. To conclude, future research is suggested to explore research needs in the areas of social aspects, social justice and equity, public policy and incentives, and ML/AI. The findings should benefit researchers and stakeholders with a holistic understanding of multidisciplinary DSG-related research and provide insight for planning new research and funding opportunities. [ABSTRACT FROM AUTHOR]

The article discusses the importance of reproducibility in academic research, particularly in the field of structural engineering. It acknowledges the challenges in achieving reproducibility, such as data storage and computing requirements, as well as proprietary issues. The authors argue for the development of a reproducibility policy in the Journal of Structural Engineering and the Journal of Bridge Engineering, taking into account the nature and culture of research in these subdisciplines. They propose a classification system that emphasizes the availability of data and metadata, and encourage authors to go beyond data availability by making models and other materials accessible. To incentivize research and data availability, the journals will provide a visible recognition badge for papers with open data/models/codes and may consider special recognition for these papers. The authors also outline the review process for data-verified papers, which involves three associate editors verifying the availability and representativeness of the data. [Extracted from the article]

Sidewalks represent a fundamental part of the infrastructure in cities, allowing equal and barrier-free access for everyone. However, while pedestrian accessibility is a frequent concern in developed countries, it receives little attention in developing regions. Regarding studies on pedestrian infrastructure, the characteristics of the sidewalk that are considered are also varied, as well as the aspects mainly focused on by such research. Moreover, the perception of the target user group, especially of people with disabilities, can be an important topic in this area. In this context, this paper presents a systematic literature review of sidewalk assessments, focusing on accessibility, to answer the following research questions. In which contexts are sidewalk assessments carried out? Which aspects and elements are usually considered? Are people with disabilities included? We noticed that sidewalk assessments have been a recent study topic, but with less focus on the Global South. Besides accessibility, walkability stands out as a research focus, and the sidewalk elements most addressed are surface conditions and width. Finally, the perceptions of people, especially with disabilities, are scarcely considered, demonstrating an important research gap. The sidewalk is a very important element of the city. It should allow walking, with accessibility for everyone. However, there are three things to consider: (i) sometimes the importance of an accessible sidewalk is not recognized in developing countries; (ii) the different characteristics and aspects of the sidewalk are considered differently between different studies; and (iii) the opinions of pedestrians, especially of people with disabilities, are not always present in evaluations of sidewalks. Thus, the aim of this study is to develop a systematic literature review to better understand how the sidewalks are evaluated in different studies, especially considering accessibility. In the study, the previous three findings were confirmed, with the conclusion that (i) evaluation of sidewalks is a recent topic of study, but mostly in developed countries; (ii) accessibility, walkability, and safety are frequent topics in sidewalk assessments, with surface conditions and width being the most evaluated characteristics; and (iii) few studies consider the opinions of pedestrians with disabilities. These three findings indicate topics that need to be better studied and focused on in urban planning. [ABSTRACT FROM AUTHOR]

The Le Chatelier--Anstett test was used to study the sulfate resistance of cement pastes containing calcined paper sludge waste (MC). MC was blended with two types of portland cement (PC): P1 with and P2 without [C.sub.3]A (ordinary portland cement, OPC, and sulfate-resistant portland cement, SRPC, respectively). The study of thaumasite formation required the utilization of a third PC, P3. The results showed that sulfate resistance always decreased at higher ratios of PC replacement by MC. This behavior was attributable to the expansive synergic effect (ESE), originated by the coprecipitation of ettringite from two resources in a gypsum and water medium. Part of the ettringite formed rapidly from the [Al.sub.2][O.sup.r-.sub.3] in MC, and rapidly or slowly from the [C.sub.3]A in P1, depending on whether its early pozzolanic activity was sufficient or not. Rapid-forming ettringite of both origins was induced by the sufficient specific, fast, and early pozzolanic activity resulting in the indirect stimulation of sulfate-mediated P1 hydration (its [C.sub.3]A content especially) by the metakaolin present in the MC. Where such activity was insufficient, however, slow-forming ettringite was generated, reducing the ESE. The substantial calcite content in MC also played a very significant role in ESE, the result of the stimulation of such hydration, concomitant sulfate attack, and thaumasite formation. Stimulation was both direct (due to initial particle moistening by the mixing water) and nondirect (due, at the very outset, to the positive and negative electrostatic charge acquired by their particles during grinding and/or mixing, and subsequently, to the zeta potential originated as PC hydration progressed). Lastly, calcite (natural or synthesized in portlandite carbonation) was shown to be needed for thaumasite to form, a process not confined solely to low-temperature environments. DOI: 10.1061/(ASCE)MT.1943-5533.0001714. Author keywords: Portland cements; Calcined paper sludge waste; Sulfate attack; Ettringite; Thaumasite.

In this study, the energy, economic, and environmental (3E) analysis on two waste-to-energy (WtE) technologies, for example, anaerobic digestion (AD) and incineration, for the treatment of municipal solid waste in Surat (Gujarat, India) was conducted. For energy criteria, the potential for energy recovery from municipal solid wastes (MSW) through AD and incineration was considered. The economic analysis that was carried out considered preprocessing, transportation, land, capital investment, and operational and maintenance costs that were incurred. The revenue that was generated by selling the electricity and compost was considered along with the recycling value of the paper waste. For environmental analysis, the global warming and acidification potentials (APs) were considered from the emissions that were produced during the treatment, transport, and disposal along with the displaced emissions. The results indicated that the average daily solid waste generation from Surat was 0.33 kg/person and the average total solid waste generation was 2080 t/day. Organic waste was the largest fraction (35.6%) followed by inert waste (13.5%), construction and demolition waste (12.4%), and recyclable waste, such as glass, rubber, and metal (11.2%). AD had less energy generation potential (9.89 MW) compared with incineration (16.99 MW). From an economic perspective, incineration had a higher profit (INR 1.48 million/day) than AD (INR 1.38 million/day). The environmental analysis showed that incineration had greater potential to reduce global warming and acidification compared with AD. The 3E analysis revealed that incineration was the superior technology choice. [ABSTRACT FROM AUTHOR]

Two investigative stages are presented in this study, which aim to establish basic standards for the use of calcined paper sludge (CPS) in the stabilization of soils. The soils were stabilized with CPS and with mixtures of CPS and cement (C). The total percentage of binder was between 3 and 6% by weight. The blending ratios (by weight) of the CPS:C mixtures were 50:50 and 25:75. The first stage took place in the laboratory, and the second stage, in the field, involved in situ stabilization of 250 m of subgrade using dry-mix methods. The bearing capacity of the stabilized soils was determined in the laboratory. In the second stage, the densities of the subgrade were measured in the field following compaction and deflections at 7 days. Furthermore, the evolution of its unconfined compressive strength (UCS) was measured over 90 days. The results reveal optimal mechanical behavior of the stabilized soil at CPS:C ratios of approximately 25:75. DOI: 10.1061/(ASCE)MT.1943-5533.0000437. CE Database subject headings: Soil stabilization; Activated sludge; Subgrades; Field tests; Paper mills; Recycling; Industrial wastes. Author keywords: Soil stabilization; Activated sludge; Subgrades; Field tests; Paper mills; Recycling; Industrial wastes.

The paper recycling process generates a sludge characterized by a high content of cellulose fiber. To understand the behavior of this fibrous material, this article presents an interpretation of the geotechnical behavior of a waste sludge from a paper recycling plant situated in southern Brazil using data from laboratory tests. Engineering properties of compacted paper mill sludges are similar to those of most fibrous organic soils: low hydraulic conductivity upon compression and high compressibility. The waste studied has a water content of approximately 250%, organic content of 48%, mineral charges, and water. The one-dimensional compressibility parameters are indicative of high compressibility. For the determination of the strength parameters of the material, undrained triaxial tests were carried out. An incredibly high effective friction angle ([PHI]' = 53[degrees]) was found, probably because of the fibrous nature of the paper sludge. In addition, hydraulic conductivity tests were performed on a flexible wall permeameter. The hydraulic conductivity of the fibrous paper sludge reached values near[l0.sup.-9] m/s. The results showed that the paper mill sludge is a ductile material with reduced hydraulic conductivity and elevated shear strength that could have multiple applications, such as in the construction of bottom liners, cover liners, and steep side-slope liners for solidwaste landfills. DOI: 10.1061/(ASCE)MT.1943-5533.0000306. CE Database subject headings: Paper mills; Sludge; Hydraulic conductivity; Fibers; Shear strength; Recycling. Author keywords: Paper mill sludge; Hydraulic conductivity; Fibers; Shear strength.

Biological and abiotic sorptions as well as kinetic experiments were performed to elucidate the mechanism by which color was being removed from paper mill effluents using anaerobic composting. Experiments were performed using pulp mill upset tank wastewater (color=5,500 PCU) and E stage filtrate (color=10,300 PCU). Color removal experiments using active and gamma sterilized compost showed that the color removal capacity for both wastewaters was nine times higher when using active compost than for those reactors using gamma sterilized compost. Final decolorization for pulp mill upset tank and E stage filtrate was 91 and 83%, respectively, while only 33% decolorization was achieved with gamma sterilized compost. Kinetic tests also showed higher color degradation rates when using active compost compared to sterilized compost. Additional experiments demonstrated that biological color removal appears to be robust with respect to pH and is largely unaffected by pH over a range from pH 5 to 10, typical values for the effluents in paper mills. The effect of aging in sorption were tested and results showed that virgin compost could establish a microbial population in less than 50 days which resulted in a compost with sorption capacity similar to the aged compost. DOI: 10.1061/(ASCE)EE.1943-7870.0000204 CE Database subject headings: Color; Anaerobic treatment; Biological processes; Paper mills; Effluents; Wastewater management. Author keywords: Decolorization; Anaerobic compost; Paper mill effluent.

The aim of this paper is to propose a step by step method to establish and validate a relevant, dynamical model of the activated sludge process for the paper mill industry. The model is established by considering the specificities of the effluent to be treated. It uses the biochemical oxygen demand (BOD) measurement, which allows a direct correlation between the state variables of the model and the measurements. This model is validated on a pilot plant of semi-industrial size fed with industrial paper mill effluents. The parameter estimation is based on an analysis of the sensitivities. The results are compared with a model based on chemical oxygen demand (COD) partitioning which is issued from the simplification of the activated sludge model number 1 (ASM1) model. Finally, the model dealing with BOD measurements not only shows the best performances, but is also the easiest to implement, overcoming one main obstacle to efficient monitoring and control in paper mill wastewater treatment plants. [ABSTRACT FROM AUTHOR]

The Journal of Construction Engineering & Management has announced the recipients of the 2023 Best Paper Award. The winning paper, titled "Deep Learning Image Captioning in Construction Management: A Feasibility Study," explores the automation of deep learning for image captioning in the construction management field. The authors present a systematic approach that includes developing a linguistic schema, creating a dataset of manually captioned images, and evaluating six deep-learning methods using eight metrics. The paper concludes that a method combining two advanced deep learning processes performed the best, and that automatic captioning in construction management is feasible. The article provides valuable insights and suggestions for future development in this area. [Extracted from the article]

This study deals with the recovery of deinking sludge (DS) generated during waste paper recycling. The aim is to integrate this sludge in the fired-bricks formulation with different percentages. These mixtures are fired, and the study of the general aspect, loss on fire, and water absorption enables characterization of this material. Different compression tests are carried out on studied samples to characterize the strength and compare its performance to the standard. The mixtures' optimization and the elaboration conditions are the main objectives to obtain a new construction material with competitive performances conforming to the standards. [ABSTRACT FROM AUTHOR]

Paper clay has several properties that make its use in vertical barriers very promising. In this paper the characteristics of two paper sludges (which will also be referred to as paper clays) one from the Erving Paper Company and one from the International Paper Company are considered. To determine the feasibility of paper clay for heavy metal attenuation, batch tests, column tests, hydraulic conductivity tests, and pressure filtration tests were performed. Batch testing showed that the metal, the distribution coefficient (Kd) ranged from as low as 0.002 L/g for manganese to as high as 6.7 L/g for lead in International paper clay. In the Erving paper clay the Kd ranged from 0.007 L/g for manganese to 1.9 L/g for cadmium, while the International paper clay Kd ranged from 0.002 L/g for manganese to 6.7 L/g for lead. Chemisorption was established as the predominant metal binding mechanism in both clays with the only exceptions being manganese adsorption on International paper clay that indicated a constant partitioning, and copper and lead on Erving paper clay that indicated constant partitioning and cooperative adsorption, respectively. Both hydraulic conductivity and pressure filtration tests revealed permeabilities ranging from 10-5 to 10-7 cm/s. Chloride testing showed that the coefficient of hydrodynamic dispersion (D) within paper clay is on the order of 10-7 cm2/s. [ABSTRACT FROM AUTHOR]

Paper mill sludge is often incinerated for heat recovery and volume reduction. In Italy, about 600,000 t of paper mill sludge is produced yearly. About 6 kg of sludge is produced per ton of paper produced. The paper mill sludge is recovered from a primary mechanical separation process. When it is combusted as a single fuel source, it produces paper mill sludge ash (PA). In this project, PA was studied to evaluate its use as a supplementary cementitious material in mortars and concrete manufacturing. On the basis of the data collected, it was concluded that PA, if used to replace up to 10% of the portland cement, shows a positive effect on the mechanical performance of mortars. On the other hand, because of its high fineness and consequently high water absorption, it required a higher amount of water. It was concluded that the use of PA should not be higher than 10% by weight of the cement replaced, unless mortar mixtures are judiciously proportioned. [ABSTRACT FROM AUTHOR]

This paper aims at proposing a calculation model to deal with the face stability of shield tunnels in unsaturated soil. Based on the existing results of centrifugal test and numerical simulation, a new failure mechanism is proposed, which combines the logarithmic spiral with upper loosening arch mechanisms. The failure mechanism considers the influence of the soil arching effect and the logarithmic spiral height coefficient. Formulas for calculating the loosening earth pressure of unsaturated soil are deduced. Subsequently, this model of loosening earth pressure is introduced into an analytical model to compute the limit support pressure on the tunnel face. Compared with other height coefficients and the degree of soil arching effect, when the height coefficient is 0.95 and the degree of soil arching effect is 10%–30%, the limit support pressure proposed in this paper is in good agreement with the centrifugal test results. Finally, comparisons are performed with the proposed model and classical models as well as typical centrifuge model tests. The comparative analysis shows that the proposed theoretical model is in good agreement with the numerical simulation. The outline of the failure zone by the theoretical model in this paper is in good agreement with the centrifuge results. [ABSTRACT FROM AUTHOR]

This study investigates the geotechnical properties of seven paper mill sludges. Paper mill sludges have a high water content and a high degree of compressibility and behave like a highly organic soil. Consolidation tests reveal a large reduction in void ratio and high strain values that are expected due to the high compressibility. Triaxial shear-strength tests conducted on remolded and undisturbed samples showed variations in the strength parameters resulting from the differences in sludge composition (i.e., water content and organic content). Laboratory permeability tests conducted on in-situ specimens either met the regulatory requirement for the permeability of a landfill cover or were very close. With time, consolidation and dewatering of the paper sludge improved the permeability of cover. Freezing and thawing cycles increased the sludge permeability about one to two orders of magnitude. Maximum permeability changes occurred within 10 freeze and thaw cycles.

The pyrolysis kinetics of cellulosic uncoated printing and writing paper, which is one of the principal materials contributing to the municipal solid waste (MSW) of Taiwan, was investigated with a thermal gravimetric analysis (TGA) reaction system. The experiments were carried out in a nitrogen environment in the 450-850 K temperature range at various constant heating rates of 1, 2, and 5 K/min. The results indicated that there were two principal reactions in TGA curves as distinguished by the two significant and distinct mass changes over the experimental conditions. The pyrolysis of uncoated printing and writing paper can be adequately described by a two-reaction model. The corresponding activation energies, preexponential factors, and reaction orders were determined. The experimental results were satisfactorily fitted by the proposed chemical reaction model.