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It is important that a sustainable community better prepare for and design mitigation processes for major flooding events, particularly as the climate is non-stationary. In recent years, there have been major storm events in the USA with record amounts of rainfall that some refer to as stalled storms. These stalled storms frequently result in flooding of urban areas which are not subject to riverine or storm surge flooding. This research focuses on using flood damage reports in conjunction with contour maps, geographical information systems, Light Detection and Ranging (LiDAR) data, photographs, and spatial averaging to develop total (high) flood elevation data sets for two neighborhoods for Tropical Storm Imelda in Beaumont, Texas. When various sources of data such as insurance or Federal Emergency Management Agency damage reports, updated LiDAR elevation sets, and coordination data are readily available, this may be an economical method of estimating maximum flood elevations. High-water marks are frequently collected by various agencies as soon as possible after a flooding event, but these data sets might provide even additional information and validation many months or years post an event.

Skid resistance of pervious concrete (PC) in comparison with traditional portland cement concrete (PCC) was investigated in the laboratory and in the field. Dry, wet, and iced PC surfaces were test...

This technical note tests the efficacy of a carbonate-laden water treatment on pervious concrete to increase its resistance to magnesium chloride (MgCl2) attack. A treatment method and an ...

Magnesium chloride deicers applications onto pervious concrete pavements can deteriorate the material, and studies investigate treatments to increase the concrete resistance to MgCl2 attacks. In this paper, pervious concrete specimens are subjected to a treatment with NaHCO3 solution, which seems to accelerate concrete carbonation and might hamper chemical reactions between MgCl2 deicer and hydroxides in cement mortar. All specimens had their compressive strength tested and the time frames before and after treatment varied. Results show that at least 2 months should be given post curing before treatment to not harm the concrete, and longer post treatment periods may be beneficial.

Loratorial tests with pervious concrete comprised porosity and hydraulic conductivity as well as mechanical parameters as compressive, indirect tensile and bending strengths besides assessing its static and dynamic elasticity moduli. Later, a pervious sidewalk area of 1.0 x 8.65 square meters was built in order to determine the variation of the infiltration rate along time; over such experimental sidewalk, impact deflection tests performed allowed to assess back calculated moduli of the pervious concrete layer, resulting 33% to 13% lower than conventional concretes. A mechanistic analysis allowed to estimate the required thickness of concrete for heavy- and light-traffic areas. Tests disclosed no significant difference among the different concrete mixes, with 25% porosity and 0,1 cm/s permeability. Initial sidewalk infiltration rate of 0.5 cm/s dropped 50% four months after construction. It was verified that pervious concrete thicknesses for trucks and buses use are far higher than conventional concrete pavements. Resumo Testes laboratoriais com concreto permeável incluíram medidas de porosidade e condutividade hidráulica, bem como parâmetros mecânicos - resistência à tração, tração indireta e flexão - além de avaliar seus módulos de elasticidade estático e dinâmico. Posteriormente uma área permeável na calçada de 1,0 x 8,65 metros quadrados foi construída para determinar a variação da taxa de infiltração ao longo do tempo; nesse experimento mediram-se deflexões de impacto na calçada, tendo sido avaliados os módulos retroanalisados da camada de concreto permeável, resultando 33% a 13% abaixo dos concretos convencionais. Uma análise mecanicista permitiu estimativa da espessura para o concreto em áreas de tráfego pesado e leve. Os testes apontaram não haver diferenças significativas entre as misturas estudadas, tendo porosidade de 25% permeabilidade de 0,1 cm/s. A taxa de infiltração inicial na calçada de 0.5 cm/s caiu 50% após quatro meses. Verificou-se que são requeridas maiores espessuras de concreto permeáveis que de concretos convencionais para sua aplicação para veículos comerciais.

The pervious concrete layer in a permeable pavement system may be susceptible to chemical degradation by various deicers applied during winter weather events. In this research, the chemica...

Pervious concrete can be utilized simultaneously as a pavement surface and part of a stormwater management system. In cold climates, it may be exposed to deicers, many of which have been sh...

Silver Nanoparticles (AgNPs) are well known for applications in electronics and as antimicrobial agents because of their unique optical, electrical, cytotoxic and thermal properties. These nanoparticles can be synthesized via a wide variety of techniques; however, they require the use of hazardous solvents which have very high environmental impacts. Nanoscience researchers have attempted novel synthesis routes that reduce resource requirements and use benign chemicals, while maintaining control over their unique properties. The present study evaluates the potential environmental impacts of one such benign method using Life Cycle Assessment (LCA) techniques which are used to assess the environmental impacts of a product's life through all the stages from raw material extraction to disposal/ recycling. This research evaluates AgNPs which were synthesized using glucose as the reducing agent and food grade corn starch as the stabilizing agent in a microwave-assisted reaction system. GaBi 6.0 software was used to carry out the Life Cycle Impact Assessment on a declared unit of 1 kg of 3.0 ± 1.2 nm diameter AgNPs. The results indicate that the impacts are predominantly on acidification (AP), human health particulate air (HHAP) and human toxicity non-cancer (HTNCP) potentials. These impacts are mainly from the production of silver metal and electricity used. The starch and glucose used to produce AgNPs of 3.0 ± 1.2 nm is shown to have negligible environmental impacts and is therefore considered to be environmentally benign.

Summary Government agencies, companies, and other entities are using environmental assessments, like life cycle assessment (LCA), as an input to decision-making processes. Communicating the esoteric results of an LCA to these decision makers can present challenges, and interpretation aids are commonly provided to increase understanding. One such method is normalizing results as a means of providing context for interpreting magnitudes of environmental impacts. Normalization is mostly carried out by relating the environmental impacts of a product (or process) under study to those of another product or a spatial reference area (e.g., the United States). This research is based on the idea that decision makers might also benefit from normalization that considers comparisons to their entity's (agency, company, organization, etc.) total impacts to provide additional meaning and aid in comprehension. Two hybrid normalization schemes have been developed, which include aspects of normalization to both spatially based and entity-based impacts. These have been named entity-overlaid and entity-accentuated normalization, and the schemes allow for performance-based planning or emphasizing environmental impact types that are most relevant to an entity's operational profile, respectively. A hypothetical case study is presented to demonstrate these schemes, which uses environmental data from a U.S. transportation agency as the basis for entity normalization factors. Results of this case study illustrate how entity-related references may be developed, and how this additional information may enhance the presentation of LCA results using the hybrid normalization schemes.

Pervious concrete systems are developing stormwater management technologies which also have wintertime benefits as melting snow may percolate into the system instead of refreezing on the surface. Enhancing the surface microtexture of pervious concrete may also be beneficial in preventing icing or slipping by pedestrians. This research explored different surface treatments on pervious concrete specimens both qualitatively from personal judgements, and quantitatively through static friction measurements with a spring balance with respect to “slipperiness”. The tests were performed on both dry and wet specimens. One aim was to determine whether the spring balance method may be a simple test for comparing surface treatments on pavement samples with little surface area such as laboratory specimens or sidewalk sections. The other purpose was to make a preliminary decision of which surface treatments to use for a sidewalk installation for future studies on wintertime performance. The reliability analysis of the spring balance results showed that there was high operator consistency. In addition, there was a high level of consistency on average results between the quantitative and qualitative methods. This implies that the spring balance test may be an acceptable methodology for comparative analyses with respect to static friction.

Pervious concrete (PC) pavement applications are growing in popularity due to the environmental and stormwater management benefits that PC can offer. However, relatively low mechanical properties and durability of PC, comparing to conventional Portland cement concrete (PCC), limit its use for vehicular applications. In this study, different size fractions of cured carbon fiber composite material (CCFCM) pieces were incorporated into a PC mixture (rPC) in three volume fractions. The goal was to determine the physical and mechanical properties of rPC in comparison to the corresponding properties of plain PC (control). Seven mixture designs were prepared in order to investigate the effect of CCFCM volume fractions as well as CCFCM particle sizes. The test results indicated that CCFCM addition enhanced the workability of the PC mixtures. rPC mixtures presented higher average infiltration rates when compared to the control mixture. Improvements in mechanical properties were seen on 28-day compressive strength (4–11%), 7-day tensile strength (11–46%) and in modulus of elasticity (6–45%). In terms of resistance to mass loss in Cantabro and surface abrasion, rPC mixtures presented various behaviors, with one mixture containing the highest volume fraction and a combined size fraction, outperforming the control in both tests. Overall, the results of this study indicate that incorporation of CCFCM is promising in improving physical and mechanical properties of PC.

A simple design method is proposed to obtain the desired porosity by controlling density and compaction efforts. Then, the w/c ratio and chemical admixture were varied to obtain the desired porosity and to evaluate their influence on the permeability and mechanical performance of pervious concrete. The incorporation of a rheology-modifying admixture showed an improvement in the densification and flowability of the mixture, which can increase the mechanical strength. For the same porosity obtained between mixtures, the decrease in w/c ratio did not influence the compressive strength but was shown to increase flexural tensile strength.

This work reports uptake coefficients and by-product yields of ozone precursors onto two photocatalytic paving materials (asphalt and concrete) treated with a commercial TiO2 surface application product. The experimental approach used a continuously stirred tank reactor (CSTR) and allowed for testing large samples with the same surface morphology encountered with real urban surfaces. The measured uptake coefficient (γgeo) and surface resistances are useful for parametrizing dry deposition velocities in air quality model evaluation of the impact of photoactive surfaces on urban air chemistry. At 46% relative humidity, the surface resistance to NO uptake was ∼1 s cm−1 for concrete and ∼2 s cm−1 for a freshly coated older roadway asphalt sample. HONO and NO2 were detected as side products from NO uptake to asphalt, with NO2 molar yields on the order of 20% and HONO molar yields ranging between 14 and 33%. For concrete samples, the NO2 molar yields increased with the increase of water vapor, ranging from 1% to 35% and HONO was not detected as a by-product. Uptake of monoaromatic VOCs to the asphalt sample set displayed a dependence on the compound vapor pressure, and was influenced by competitive adsorption from less volatile VOCs. Formaldehyde and acetaldehyde were detected as byproducts, with molar yields ranging from 5 to 32%.

Extending lube oil-drain intervals is a practical way to save money on engine operating costs. At the same time, there may be increased risk of engine damage with increased drain intervals. The risks and benefits can be difficult to weigh and, as a result, starting an oil-drain interval extension programme can be an intimidating endeavour. This paper combines oil-analysis programme data interpretation and life-cycle cost analysis (LCCA) into a methodology for weighing oil-drain interval options. LCCA has shown decreasing incremental cost savings as oil-drain intervals are further extended, indicating that highly extended drain intervals may not be necessary to reap the majority of available cost benefits. Using oil-analysis property trending with life-cycle cost savings can allow an engine operator to set an hours-based extended drain interval based on projected risks and benefits. This interval is set as the baseline under the protocol, but continual oil analysis is used as a precaution to protec...

Pervious concrete may be used for stormwater management since it allows the water to pass through its interconnected macropores into stormwater systems or soils below. However, there is a need for additional standards related to pervious concrete prior to its widespread use, and there are many aspects related to mix design for desired properties, compaction methods, and test procedures that are not yet completely understood. These variables may significantly affect the functional and mechanical performance of the material. In this paper, mix designs and test specimen preparation techniques were evaluated. The IBRACON method for mixture design was used to obtain the mixture proportions and the calculated density for the desired porosity of 25%. In addition, two different types of specimens (cast or cored) and compaction methods (roller or Proctor hammer compacted) were performed. The density of each specimen was controlled to obtain the same calculated density. Several tests were conducted to compare the following variables: density, porosity, surface infiltration rate, permeability and compressive strength. Additionally, the effects of mortar capping versus neoprene-rubber caps on compressive strength measurements of pervious concrete were evaluated. The experimental results showed that cast specimens have more consistent results than cores. The design method studied with strict control of density was efficient to obtain the desired porosity mainly for cast specimens. The roller leads to a more compacted top surface resulting in a decrease in the infiltration rate and permeability of the cores. The mortar capping method is more consistent than the other. Resumo O concreto permeável é um material de potencial para ser utilizado no gerenciamento de águas pluviais, uma vez que permite a percolação da água através de seus macroporos interconectados, seja para sistemas de águas pluviais ou para o próprio solo. No entanto, há uma necessidade de normas adicionais relacionadas ao material para seu uso difundido e, ainda, há muitos aspectos relacionados aos parâmetros de dosagem para propriedades desejadas/projetadas, método de compactação e procedimentos laboratoriais, que ainda não foram completamente compreendidos. Tais variáveis podem afetar significativamente o desempenho funcional em termos hidráulicos e mecânicos do material. Neste trabalho, o método do IPT/EPUSP para dosagem foi utilizado para obter as proporções de mistura e a densidade calculada, para uma porosidade desejada de 25%. Além disso, dois tipos diferentes de amostras (moldadas e extraídas) e métodos de compactação (Proctor e rolo) foram realizados. A densidade de cada amostra foi controlada para obter a mesma densidade calculada. Diversos testes foram realizados para comparar as seguintes variáveis: densidade, porosidade, taxa de infiltração, permeabilidade e resistência à compressão. Além disso, foram avaliados os efeitos do tipo de capeamento (com argamassa e com borracha de Neoprene) nos corpos de prova submetidos ao ensaio de compressão. Os resultados experimentais mostram que os corpos de prova moldados apresentam resultados mais consistentes que as amostras extraídas. O método de dosagem, com controle rigoroso da densidade, foi eficiente para obtenção da porosidade desejada, principalmente para os corpos de prova moldados. O rolo conduz a uma superfície superior mais compacta, o que resulta na diminuição da taxa de infiltração e permeabilidade para as amostras extraídas. O capeamento dos corpos de prova com argamassa apresenta resultados mais consistentes.

This study evaluated changes in moisture and temperature of clay soils next to an underground aggregate storage bed of a pervious concrete pavement system during the winter in Pullman, Wash...

Pervious concrete pavement systems may have many environmental benefits including the mitigation of heat island impacts. This mitigation is a complex combination of pervious concrete‟s insulating capability and its ability to store water which may provide evaporative cooling. However, the introduction of water may also bring heat into the system, where the system is the pervious concrete pavement layer over an underground aggregate bed for retention and/or detention of stormwater. This study involved three different mix design placements in southern Brazil on a hot sunny summer day. The experiment had a control section and two test spots where controlled artificial rain events were introduced at two times during the afternoon for each of the three placement types. The „rain‟ initially brought heat from the surface into the pervious concrete layer. Subsequent evaporation cooled these interior pavement layers to levels similar to the control locations. This introduction of water into pervious concrete with very hot surface temperatures in the heat of the day is expected to be a severe condition for adding heat to the system through the flow of water. If water additions are made at different diurnal times, such as nighttime rain, they may provide similar evaporative benefits with less heat transfer into the system via the water phase, and thus even more cooling of the system. These experiments reinforce the conclusion that pervious concrete may be a cool pavement during summer conditions, even under extreme conditions when surface heated stormwater enters the system. Keywords: pervious concrete pavement, stormwater, heat island

Stormwater runoff, a substantial source of nonpoint pollution, can be treated using Best Management Practices (BMPs), such as the Media Filter Drain (MFD). An MFD is a trench filled with an engineered media mix, usually with a grass overlay, that receives runoff from the paved roadway next to it. The MFD was shown to remove dissolved metals (zinc and copper), typical pollutants from vehicles and urban areas, which might negatively impact aquatic species in receiving waters, but its long-term effectiveness was not known. Existing media filter mixes of different ages were collected from two different sites in the Pacific Northwest of the United States. Columns made with these media mixes received concentrated copper and zinc loading to simulate accelerated aging for estimated total lifespans from 14 to 22 years of copper and zinc loading, with little or no decrease in sorption. Throughout the aging process, some columns were subjected to performance testing with higher levels of typical runoff concentrations and average concentration decreases from influent to effluent were found to be greater than 90% for both copper and zinc. Based on this study, the MFD’s lifespan for zinc and copper treatment is significantly greater than the initial ten-year estimate.

There are multitudes of sustainability rating systems and guidelines, and it is difficult to decide which ones to use and how to use them. In addition, multi-modal projects have different focal areas and associated rating systems related to each mode or other aspect of the project. Five green ratings systems representative of aspects of a multi-modal ferry facility had previously been selected and were used in a four step methodology to synthesize into a strategic decision making platform. This current research focuses on how to make more detailed decision making harmonization amongst the credits in the rating systems. Using an analytical hierarchy process (AHP) of the credits in the rating systems, it was determined that the two main groups of information that could be used for harmonization were key intents or goals (KI) and key strategies or practices (KS). A short cursory case study example of how these KIs and KSs might be further cross-coded in an open database with the credit subcategories and corresponding rating systems is also presented. The database can filter the credit subcategories across the rating system for a specific key intent or key strategy. The harmonized lists and database may facilitate decision makers and construction managers in correlating intents and methodologies for a project across multiple rating systems.

To ensure that indoor air quality mitigation approaches, such as ventilation, are providing the desired indoor air quality, it is necessary to better understand the varied sources of indoor air contaminants and how different mitigation approaches will affect those sources. This article describes a generalized model that describes the efficacy of different indoor air quality improvement strategies as a function of the primary source(s) of indoor air contaminants of concern. The model is then used as a framework to compare the impact of two different ventilation approaches (a continuous exhaust ventilation strategy compared to a runtime ventilation strategy) on two indoor air compounds (CO2 and formaldehyde) based on primary data gathered in 10 homes in Gainesville, FL. The findings from the Gainesville data suggest that the two approaches provided similar efficacy for reducing CO2 concentrations, but the continuous exhaust system was not as effective at decreasing interior concentrations of formaldehyde, as compared to the runtime ventilation strategy. The simplified, generalized model could be used as a framework to analyze and compare existing detailed modeling and experimental results to bring about a greater understanding of the relative efficacy and tradeoffs of different IAQ mitigation strategies in homes, as well as inform guidance or standards addressing indoor air quality in residential buildings and serve as a decision-making tool for building industry professionals responsible for specifying ventilation systems in homes.

Pervious concrete placements in many locations are subject to cold weather conditions and varying levels of clogging and rejuvenation. This study focuses on field surface hydraulic performa...

Addition of sustainability-related material is becoming a point of emphasis in engineering education. Freely available modular lessons are one way to quickly effect this incorporation. This research examines the effectiveness of a class format using short prerecorded software modules on lifecycle assessment (LCA) in the classroom setting with associated discussion, primarily drawing from student perspectives in a graduate-level LCA course at Washington State University. Survey results indicated that students generally agreed that the in-class module-discussion format was an effective teaching method. Advantages included that the format was organized and complete, but still concise, allowed for review of material outside of class, and that discussion components furthered understanding and stimulated further thought about the concepts. Key disadvantages included that the modules can get boring, were sometimes too fast-paced, and that questions usually were held until the end of the presentation. Stu...

The increased rate of carbon dioxide sequestration (carbonation) is desired in many primary and secondary life applications of concrete in order to make the life cycle of concrete structures more carbon neutral. Most carbonation rate studies have focused on concrete exposed to air under various conditions. An alternative mechanism for accelerated carbon sequestration in concrete was investigated in this research based on the pH change of waters in contact with pervious concrete which have been submerged in carbonate laden waters. This may be pertinent for applications of concrete reuse in marine or other aqueous applications such as jetties and riprap. The results indicate that the concrete exposed to high levels of carbonate species in water may carbonate faster than when exposed to ambient air, and that the rate is higher with higher concentrations. Validation of increased carbon dioxide sequestration was also performed via thermogravimetric analysis (TGA). It is theorized that the proposed alternative mechanism reduces a limiting rate effect of carbon dioxide dissolution in water in the micro pores of the concrete.

Concrete can sequester CO 2 from the air in a reaction commonly called carbonation. High levels of carbonation near the surface of concrete samples have been widely studied since they may lower the pH of the concrete and alter the characteristics of a concrete structure if they migrate deeper into the structure. However, little information is available about the levels of CO 2 sequestration in interior portions of concrete pavements. This study focuses on the spatial distribution of carbonation levels across the thickness of concrete sidewalk samples that are many decades old. For 120 mm thick sidewalk samples, the average carbonation percentage was found to be 80% for specimens located near the surfaces, and 25% for specimens located in the inner part of the samples (20–80 mm from the top surface). For a 160 mm thick sidewalk sample, the average carbonation was 28% for all interior specimens at least 20 mm from surfaces. These interior levels for various concrete pavements at various ages can be used together with surface carbonation information to estimate CO 2 sequestration in concrete pavements.

This research investigated whether pervious concrete is effective in removing dissolved zinc and copper contaminants from stormwater runoff. Pervious concrete cylinders were loaded in the laboratory with simulated runoff, and influent and effluent concentrations and volumes measured. In one set of tests, stormwater was dispensed at typical concentrations (100 μg/L Zn and 20 μg/L Cu) simulating ten consecutive storm events of 12 mm (0.5 in.) of rain to test initial removal performance. Another set of cylinders was loaded at forty times the typical concentration to simulate accelerated longterm metal loading indicative of several years of typical use. Cylinders were removed after 15 and 24 accelerated events respectively for further typical concentration performance testing. Performance for the typical concentration tests both pre and post accelerated loading were calculated as a percent metals retained and also as a percent decrease in effluent versus influent concentration. The pre accelerated metal loading results indicate averages of 93% and 91% retained, and 90% and 87% concentration decreases for Zn and Cu respectively. Similar percentages were retained post accelerated metal loadings with slightly lower averages for copper after 24 accelerated loading events, although this was probably due to a higher infiltration rate. Removals were seen to be effected by both physical (water trapping) and by chemical (sorption and complexation) processes.

Pervious concrete has the unique characteristic of allowing water to pass through its porous matrix. . Pervious concrete pavement systems usually have three main layers, pervious co ncrete on the top, a subbase layer of aggregate for water storage in the middle and the subgrade (soil) layer below. Finite element mod eling of this novel material is challenging due to its complex porous characteristics. In this paper, a method has been p roposed to model pervious concrete pavement using f inite element methods, which includes a modified approach to capture the unique vertical porosity distribution in the pervious conc rete layer by averaging the distribution in three distinct vertical sections. The mechanical properties of the pervious concrete l ayer are assumed to vary along its depth since the porosity of the pervious concrete a lso varies with depth. ABAQUS, a general-purpose fi nite element software package was used to develop the model and perform the analy sis. The model was validated through a convergence study, and in comparison with the analytical theory of tensile stress and de flection for traditional concrete pavement. In addi tion, the significance of the porosity distribution model was validated by compar ing the results from EverFE ‐ a specific software f or pavement structure analysis. It was found that there is significant difference itensile stress if modeled using the modified vert ical porosity distribution in the previous concrete layer to more fully capture its v ertical porosity distribution, as compared to an av eraged porosity model in the previous concrete layer. It was also noted that com pressive stress demand may have increased importanc e for pervious concrete, but only for highly porous applications which are not cused.

When attempting to achieve sustainability goals for integrated facilities, many green rating systems are available to guide the design, construction, operations and maintenance of a project. Due to the large number of sustainability tools that are available or mandated, it can be confusing to determine which set of guidelines to follow. For the Washington State Ferries (WSF), there is no green rating system which correlates perfectly with the unique intermodal challenges presented by ferry terminals. This paper focuses on five rating systems applicable to WSF: GreenLITES, LEED, Sustainable Sites Initiative, The Port Authority of NY/NJ Sustainable Infrastructure Guidelines (draft), and the draft Marine Vessel Environmental Performance Assessment (MVeP). These rating systems are integrated with a developing set of sustainable ferry guidelines in a green rating integration platform (GRIP). The GRIP readily relates credits and guidelines across multiple systems, aiding WSF in making decisions in accordance with sustainability goals. The GRIP format might similarly be applied to other integrated projects to more effectively and economically address sustainability across all aspects of projects and facility operations.

Widespread adoption and acceptance of pervious concrete systems in new areas using local materials and equipment are dependent on having information on the efficacy of the mix and their longterm needs for rehabilitation. In Porto Alegre, Brazil recent governmental mandates include incorporating permeable pavements into projects. This study expanded on research into the effectiveness of using readily available aggregate for adequate hydraulic performance and clogging resistance of pervious concrete to also determine the effectiveness of maintenance procedures. Laboratory specimens from three mixes with differently screened aggregate were cast and infiltration rates evaluated initially, post clogging, after sweeping and after powerwashing. The results indicate that all three mixes maintain similar hydraulic functionality after rehabilitation, and that powerwashing is more effective in rejuvenating infiltration capabilities than sweeping. In addition, it is recommended to perform infiltration testing twice after maintenance, as there is a slower rate measured on the second test, probably due to dislodged debris re-entering the system during the first test. Similar laboratory methodologies for mix design and maintenance evaluation might effect a faster and more efficient incorporation of this sustainable low impact development technology in other regions.

To expand the applications of pervious concrete, additional research and testing must be conducted as to its structural performance. Distress surveys were performed on two field installations of pervious concrete subjected to equivalent traffic stresses as some collector streets in use for 20 years. The results of the distress survey were then used to calculate the pavement condition index (PCI) using the procedure from ASTM D6433. The PCI rating was considered to be a quantification of structural performance. The high PCI ratings of the thicker pervious concrete sections indicated that pervious concrete, when properly designed, is capable of being used for most residential streets and many collector streets for typical design life durations (20–30 years) while exhibiting satisfactory structural performance.

As the world becomes more urbanized, concerns over the urban heat island (UHI) are more pronounced. Increased urban temperatures have a negative affect on the natural and human environment by producing increased energy usage and smog formation. Pervious concrete pavement is one technology that may help mitigate increased urban temperatures. Temperature data from an instrumented site in Iowa and heat storage phenomena for various weather patterns are presented. The site contains both pervious concrete pavement with a solar reflectance index (SRI) of 14 and traditional concrete pavement with an SRI of 37. Leadership in Energy and Environmental Design (LEED) accepted a high SRI (>29) as one method to characterize a cool surface. Heat capacities of both systems were studied along with a sensitivity analysis of the inputs. The research supports the conclusion that even though pervious concrete may have a much lower SRI than traditional concrete made with similar materials, it can be considered a cool pavement option. In addition, daytime rainfalls combined with the internal high surface area result in significantly more removal of stored heat from the system, with a more rapid mitigation of UHI impacts and reduction in the potential for thermal shock from impervious surface runoff.

Heat and moisture transfers can lead to considerable fluctuations in thermal and moisture related properties in a soil system caused by daily and seasonal temperature changes. Of interest i...

Environmental product declarations (EPDs) are reports of resource use and potential environmental impacts based on environmental life cycle assessment (LCA) methods. They tend to be related to a specific 'gate' such as prior to use or construction. Asphalt paving and some other industries have some features that might not readily be captured in EPDs if the impacts are only included to the gate. These include stored energy (feedstock energy), stored carbon, recycled content and its high recyclability. The feedstock energy and stored carbon might be valuable assets for future considerations. This research proposes the use of optional reporting modules in EPDs based on international standards to capture the stored energy and carbon, and recyclability aspects. These proposed schemes for expanding EPDs with these benefits and loads beyond the system boundary information modules, should allow decision makers and life cycle analysts to have more comprehensive information for future decisions, research and analyses.

Anthropogenic releases of carbon dioxide are being studied with respect to the global carbon dioxide cycle. Concrete, the most used building material in the world, contributes to these releases significantly in the manufacturing of cement, both from energy use and from the calcination chemical process. The reverse process, carbonation, in which the hydrated cement reacts with carbon dioxide to form calcite, is being studied under many different circumstances for its potential to balance this release by sequestering carbon dioxide. This research focuses on other carbon dioxide sequestration species within concrete. It is hypothesized, and has been shown in some cases, that many other dissolved carbon dioxide complexes exist within the cement paste matrix, as they do in many aqueous-based systems and also that carbonate species other than calcite may exist. It is shown that carbon dioxide species, other than calcite, do exist in cement paste samples in amounts that are significant with respect to the stoichiometric potential for reversing the calcination process.

There is great interest in preventing the spread of acute respiratory infections (ARI) in military housing and in other facilities with multiple occupants such as hospitals. There has been some research on the mode of transmission of ARIs in these types of occupancies, with several studies focusing on direct and indirect contact. This study, based on several barracks at the largest basic training facility for the Army in the United States, investigates the role of airborne transmission via heating, ventilating and air conditioning (HVAC) systems as compared to a combination of airborne, indirect contact and direct contact transmission in a room. The results indicate that there is a significant increase in the number of cases which might be attributable to airborne transmission via HVAC systems in several situations, both for ARIs that required hospitalization, and those which did not.

Civil engineering is an interdisciplinary field, and most of the projects designed and built represent very complex systems, both during the construction phase and in the built phase. This research describes how a course in land development that included engineering design elements, lectures that also touched on other related fields, and a field journal assignment at a “green” (sustainable) construction site facilitated students’ understanding of complex systems. Results suggest that this course design facilitates the development of students’ proficiencies in several skill sets, and can increase students’ understanding of the complexity involved in civil engineering projects.