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Articles 3121 - 3150 of 11807
Full-Text Articles in Engineering
New Model For Natural Carbonation Prediction In Reinforced Concrete – Concept And Validation On Chemical Admixtures, Stephen O. Ekolu, M Raats
New Model For Natural Carbonation Prediction In Reinforced Concrete – Concept And Validation On Chemical Admixtures, Stephen O. Ekolu, M Raats
International Conference on Durability of Concrete Structures
A new model for prediction of natural carbonation in reinforced concrete structures has recently been developed and presented in (Ekolu, 2018). For brevity, the model is referred to as ESS model. It employs concrete strength as the primary property depicting core carbonation behaviour of any given concrete while other factors induce secondary influence. Chemical admixtures in concrete significantly influence concrete behaviour. Using experimental data from the literature (Dan-Herrera et al., 2015), the model behaviour is verified under use of various types of chemical admixtures of concrete including internal curing, shrinkage reducing, viscosity modifying, and high range water reducing admixtures. Class …
Absorption, Porosity, Capillarity And Chloride Diffusion In Ultra High Performance Concretes, José Manuel Gandia-Romero, José Enrique Ramón-Zamora, Isabel Gasch, Manuel Valcuende, Rafael Calabuig, Victor Calvet, Pedro Serna
Absorption, Porosity, Capillarity And Chloride Diffusion In Ultra High Performance Concretes, José Manuel Gandia-Romero, José Enrique Ramón-Zamora, Isabel Gasch, Manuel Valcuende, Rafael Calabuig, Victor Calvet, Pedro Serna
International Conference on Durability of Concrete Structures
Concrete durability performance can be assessed by a number of parameters, among which permeability properties are key. In this experimental work, the permeability to water and the diffusion of chlorides in Ultra High Performance Concrete (UHPC) are studied. To this end, three types of concrete were made: two Ultra High Performance (one with fibers and one without fibers) and a Conventional Concrete (CC) of w/c ratio equal to 0.5. The compressive strength of Ultra High Performance Concretes was 130 MPa, and that of conventional concrete was 50 MPa. All of them were cured at a temperature of 20°C and RH …
The Influence Of Waste Glass Powder On The Chloride Binding Capacity Of Fly Ash/Cement Hardened Paste, Jh Yan, Tingyu Hao
The Influence Of Waste Glass Powder On The Chloride Binding Capacity Of Fly Ash/Cement Hardened Paste, Jh Yan, Tingyu Hao
International Conference on Durability of Concrete Structures
The potential of using waste glass powder to increase the chloride binding capacity of fly ash/cement hardened paste was investigated. When only fly ash replacing cement, the chloride binding capacity was raised within 28d when the fly ash replacement level was in the range from 30-50% by mass. But at a longer age of 60 to 90d, the binding performance was increased at the replacement level of 10-30wt%. The chloride binding capacity of glass powder-fly ash-cement system was increased by adding glass powder of 2% and 4% by mass at 7d while those at larger addition and longer age reduced. …
Alkali Reactive Carbonate Rocks: Is It Alkali Silica Reaction (Asr) Or Alkali Carbonate Reaction (Acr)?, Mengesha Beyene, Rc Meininger
Alkali Reactive Carbonate Rocks: Is It Alkali Silica Reaction (Asr) Or Alkali Carbonate Reaction (Acr)?, Mengesha Beyene, Rc Meininger
International Conference on Durability of Concrete Structures
The root cause of distress in two different concrete structures made from carbonate coarse aggregates that fit the textural and compositional criteria cited for ACR was found to be caused by ASR, not ACR. Stereo-optical examination and transmitted polarized light microscopy (PLM) analysis showed that the concretes contain some dark gray, fine-grained argillaceous dolomitic coarse aggregates in which secondary white deposit filling the cracks extending from these aggregates into the paste (as well as lining air voids) is ASR gel. Back scattered electron (BSE) imaging with EDS spectra and x-ray elemental mappings, clearly confirm that the white secondary deposits consist …
Impact Of Portlandite On Alkali-Silica Reaction Of Pyrex Glass And Blastfurnace Slag Aggregate, Natsumi Noguchi, Tomohiro Kajio, Yuka Morinaga, Yogarajah Elakneswaran, T Nawa, Toshiki Ayano
Impact Of Portlandite On Alkali-Silica Reaction Of Pyrex Glass And Blastfurnace Slag Aggregate, Natsumi Noguchi, Tomohiro Kajio, Yuka Morinaga, Yogarajah Elakneswaran, T Nawa, Toshiki Ayano
International Conference on Durability of Concrete Structures
In this study, it is investigated the effect of Ca ion on dissolution and reaction products in alkaline environment using Pyrex glass showing ASR expansion and blast furnace slag fine aggregate suppressing ASR. It is reported that Ca plays a role in the dissolution and polymerization of silica, and is therefore an important factor in ASR. For each sample, calculation of dissolution rate and analysis of solid phase product by 29Si MAS NMR and XRD/Rietveld analysis, and liquid phase analysis by ICP-AES were performed. As a result, it was confirmed that addition of Ca has an influence on dissolution behavior …
Comparison Of Alkali-Silica Chemical Reaction Of Reactive Glass And Chert Aggregate, Yuka Morinaga, Elakneswaran Yogarajah, Toyoharu Nawa, Lalita Yongchaitrakul, Eiji Iwatsuki
Comparison Of Alkali-Silica Chemical Reaction Of Reactive Glass And Chert Aggregate, Yuka Morinaga, Elakneswaran Yogarajah, Toyoharu Nawa, Lalita Yongchaitrakul, Eiji Iwatsuki
International Conference on Durability of Concrete Structures
Alkali silica reaction (ASR) is one of the most important factors of deterioration of Concrete. However, there are a lot of unknown points about ASR such as mechanism of ASR and pessimum effect. We investigate to the mechanism of Alkali silica chemical reaction by using two different aggregates, early type expanded aggregate and delayed type expanded aggregate. Experiments were used to investigate ASR by reaction between reactive silica and alkali ions with or without calcium ions. Two phases of reacted samples (liquid and solid) are presented. In the absence of calcium hydroxide (CH), reactive materials with specified sizes (Yorochert, and …
Performance Of Concrete Made With A Calcined Clay – Limestone-Portland Cement Exposed To Natural Conditions, Fernando Martirena, Ernesto Díaz, Dayran Rocha, Hamed Maraghechi, Karen Louise Scrivener
Performance Of Concrete Made With A Calcined Clay – Limestone-Portland Cement Exposed To Natural Conditions, Fernando Martirena, Ernesto Díaz, Dayran Rocha, Hamed Maraghechi, Karen Louise Scrivener
International Conference on Durability of Concrete Structures
This work presents the results of an investigation carried out to assess durability of concrete made with a calcined clay- limestone-Portland cement with 47% of clinker, hereafter named LC3, produced during an industrial trial in 2013. LC3 was used to cast concrete blocks and later expose them at a natural location at the northern coast of Cuba. Reference concrete was cast with Cuban Portland cement having 88% of clinker. Throughout three years (2015, 2016, 2017) concrete cores were systematically taken and the specimens were subjected to a testing program that included Formation factor, chloride profiling, surface resistivity, air permeability and …
Workability And Freeze-Thawing Performance Of Fiber Reinforced Expansive Self-Consolidating Concrete, Qi Cao, Qq Gao
Workability And Freeze-Thawing Performance Of Fiber Reinforced Expansive Self-Consolidating Concrete, Qi Cao, Qq Gao
International Conference on Durability of Concrete Structures
The aim of this study is to investigate the workability and freeze-thawing performance of fiber reinforced expansive self-consolidating concrete (ESCC). Fibers and expansive agent were used to decrease shrinkage, control cracks and enhance microstructure of the concrete. Steel fibers with three volume fractions (0.25%, 0.50%, 0.75%) of the total volume of concrete and monofilament polypropylene fibers with two volume fractions (0.05%, 0.10%) were used in the test. The freeze-thawing performance was determined by rapid freezing and thawing test. Results indicated that polypropylene fiber shows more sensitivity on slump flow than steel fiber but less impact on T500. The relative dynamic …
Polymer Binder, Impact On The Pull-Out Force Of Macro Fibers In Sprayed Concrete, Klaus Bonin, Christina Neumaier
Polymer Binder, Impact On The Pull-Out Force Of Macro Fibers In Sprayed Concrete, Klaus Bonin, Christina Neumaier
International Conference on Durability of Concrete Structures
Macro-fibers have been used in sprayed concrete for many years now, particularly to prevent cracks from developing in the concrete due to deformation energy. These fibers can be made of steel or plastics and are provided for the Application. The type of fiber to be used is selected based on the building project’s requirements. Usually, the fibers are added to the sprayed concrete in the standard application’s mixture, regardless of whether the concrete is wet or dry (fiber-reinforced concrete or FRC). FRC’s functional principle is to mechanically anchor the steel or polymer fibers in the dense matrix of the binder …
Strength And Durability Performance Of Ultra-High-Performance Cementitious Composite Enhanced With Carbon Nanofibres, Jlg Nim, Sudharshan Naidu Raman, Mfm Zain, R Hamid, Fc Lai
Strength And Durability Performance Of Ultra-High-Performance Cementitious Composite Enhanced With Carbon Nanofibres, Jlg Nim, Sudharshan Naidu Raman, Mfm Zain, R Hamid, Fc Lai
International Conference on Durability of Concrete Structures
Ultra-high-performance concrete (UHPC) is known for exhibiting excellent strength and a more durable matrix compared to conventional concrete. Typically UHPC consists of carefully selected constituent materials of: ultrafine graded sand, silica fume (or other alternative binders), steel micro-fibres, and ordinary (or special blends) Portland cement. This study was initiated to synthesize a new blend of Ultra-high-performance cementitious composite (UHPCC) with compressive strength higher than 150 MPa under normal curing conditions, and to investigate the influence of two different sources of carbon nanofibres (CNF) on its strength, durability and microstructure properties. Several mix designs with different CNF percentages were designed, optimised …
Post-Cracking Behavior Of Cementitious Composite Incorporating Nano-Silica And Basalt Fiber Pellets, Ahmed Bedwiy, Mohamed T. Bassuoni, Ehab El-Salakawy
Post-Cracking Behavior Of Cementitious Composite Incorporating Nano-Silica And Basalt Fiber Pellets, Ahmed Bedwiy, Mohamed T. Bassuoni, Ehab El-Salakawy
International Conference on Durability of Concrete Structures
Recently, fiber reinforced polymers (FRPs) have been increasingly used to reinforce concrete structures in harsh environments, due to their non-corrodible nature. Developing a nonferrous reinforcement system (corrosion-free system) for concrete using FRP bars along with discrete fibers is a promising option for exposed concrete structures in cold regions or marine environments. Incorporating highly efficient non-metallic fibers into any cementitious composite is capable of reducing bleeding, controlling shrinkage cracking, and improving toughness and impact resistance. Therefore, in this study, a new type of basalt fiber pellets with high tensile strength was investigated. This paper reports on the flexural performance of the …
Long Term Permeability And Acid Resistance Of Selfcompacting Concretes With Micro And Nano Mineral Additions, Gonzalo Barluenga, Cynthia Guardia, Javier Puentes, Nelson Flores
Long Term Permeability And Acid Resistance Of Selfcompacting Concretes With Micro And Nano Mineral Additions, Gonzalo Barluenga, Cynthia Guardia, Javier Puentes, Nelson Flores
International Conference on Durability of Concrete Structures
Self-Compacting Concrete (SCC) can incorporate different types of Supplementary cementitious materials (SCM), as filler and other active mineral additions, to increase the amount of paste without increasing the amount of cement. SCM modify the SCC hardened microstructure due to the filler effect, the seeding effect as nucleation points for hydration products and the pozzolanic effect in the case of reactive SCM, as mineral additions (MA). The pore network is also modified which produce changes in the permeability of SCC. It is generally considered that the increase of fine particles improves SCC durability due to the larger compactness of the hardened …
Effect Of Nanosilica On The Sulfate Attack Resistivity Of Cement Mortar, Pengkun Hou, Zh Guo, Q Yu, N Xie, X Cheng, Sp Shah
Effect Of Nanosilica On The Sulfate Attack Resistivity Of Cement Mortar, Pengkun Hou, Zh Guo, Q Yu, N Xie, X Cheng, Sp Shah
International Conference on Durability of Concrete Structures
The effect of nanosilica on the sulfate attack resistivity of cement mortar was investigated through study on the mechanical property evolution and the length change of the cement mortar under 5 wt.% sodium sulfate for 6 months. Meanwhile, the effects were compared with those of fly ash-replacement mortar. Results showed that by taking the advantages of nanosilica and fly ash in improving the property of cement mortar at early and later ages, the sulfate attack resistance of cement mortar can be enhanced in mechanical property increase and expansion reduction. Further, it implies that a combination of both pozzolans could enhance …
The Synergistic Effect Of Nano-Silica With Slag On Frost Resistance Of Concrete, Yuan Lianwang, Zhou Zonghui, P Du, X Cheng, P Hou, L Zhang, Q Li
The Synergistic Effect Of Nano-Silica With Slag On Frost Resistance Of Concrete, Yuan Lianwang, Zhou Zonghui, P Du, X Cheng, P Hou, L Zhang, Q Li
International Conference on Durability of Concrete Structures
The frost resistance of concrete is one of the most important factors for its durability. Supplementary cementitious materials could effectively improve the frost resistance of concrete. On this basis, the synergistic effect of nano-silica (NS) with slag on the frost resistance of concrete is better than the single, which was investigated. Nano-silica and slag were employed as a partial substitute of cement. The effect of these on the related indexes, including the mass loss, relative dynamic elastic modulus and porosity of concrete were measured after specified number of freeze and thaw cycles. Results show that the frost resistance of nano-silica …
Enhancement Of Durability Characteristics Of Geopolymer Concrete With Manufactured Sand, Abdul Aleem, T Shanmuga Priya
Enhancement Of Durability Characteristics Of Geopolymer Concrete With Manufactured Sand, Abdul Aleem, T Shanmuga Priya
International Conference on Durability of Concrete Structures
Geopolymer Concrete is the concrete made without using any quantity of cement. Instead the waste material from the thermal power station called fly ash is used as the binding material. This fly ash reacts with alkaline solution like sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) and forms a gel which binds the fine and coarse aggregates. Similarly another artificial material called manufactured sand (M-Sand) is also used as the fine aggregate against the normal river sand. The durability of Geopolymer Concrete with M-sand was studied by casting cubes of size 100 x 100 x 100 mm. The cube specimens were …
A Preliminary Investigation Into Geopolymer Cement Mortar’S Suitability For Providing Resilient Highway Solutions, Bryan Magee, A Wilkinson, D Woodward, S Tretsiakova-Mcnally, P Lemoine
A Preliminary Investigation Into Geopolymer Cement Mortar’S Suitability For Providing Resilient Highway Solutions, Bryan Magee, A Wilkinson, D Woodward, S Tretsiakova-Mcnally, P Lemoine
International Conference on Durability of Concrete Structures
Despite local and national road authorities striving to provide motorists with a durable and safe infrastructure environment, one in six UK roads are currently classed as being in poor condition. In terms of safety, Department for Transport statistics continue to report high numbers of road fatalities; 1,780 in 2015, representing a 3% increase from the previous year. As such, research focused on developing resilient and cost effective planned/preventative highway maintenance solutions remains highly topical. Reported in this paper is research aimed at developing high performance, low impact solutions for both highway repair and skid resistance enhancement. A metakaolin/alkali silicate-based geopolymer …
Comparison Of Lithomarge And Cement-Based Mortars Performance In Aggressive Aqueous Environments, Jacek Kwasny, Timothy A. Aiken, Marios N. Soutsos, Andrew J. Mcintosh, David J. Cleland
Comparison Of Lithomarge And Cement-Based Mortars Performance In Aggressive Aqueous Environments, Jacek Kwasny, Timothy A. Aiken, Marios N. Soutsos, Andrew J. Mcintosh, David J. Cleland
International Conference on Durability of Concrete Structures
The resistance of room temperature cured geopolymer mortar (GPM) against chemical attacks, i.e. sodium and magnesium sulfate solutions, and sulfuric and hydrochloric acid solutions, was evaluated. GPM was formulated using a lithomarge precursor (low-purity kaolin) to achieve 28-day characteristic compressive strength of 60 MPa. Its performance was compared with an equivalent Portland cement mortar (PCM) having the same paste volume and strength grade. 28-day old bar samples were stored in 0.352 mol/L sulfate solutions for 52 weeks whereas 28-day old cube samples were exposed for 8 weeks to acid solutions with concentration of 0.52 mol/L. GPM showed superior performance against …
Influence Of Sulfide On The Onset Of Chloride-Induced Corrosion Of Steel Reinforcement In Alkali-Activated Slags., Maria Criado, Shishir Mundra, Susan Andrea Bernal, John Lloyd Provis
Influence Of Sulfide On The Onset Of Chloride-Induced Corrosion Of Steel Reinforcement In Alkali-Activated Slags., Maria Criado, Shishir Mundra, Susan Andrea Bernal, John Lloyd Provis
International Conference on Durability of Concrete Structures
In alkali-activated slags (AAS), where ground granulated blast furnace slag is used as the main precursor, the presence of reduced sulfur species yields a highly reducing pore solution environment. This study investigates the influence of sulfide on steel passivation in alkali-activated slag mortars immersed in alkaline (1 M NaOH) and alkaline chloride-rich (1 M NaOH with 5 M NaCl) solutions, and the dependency of chloride-induced pitting on the immersion time and the concentration of sulfide in simulated alkali-activated slag pore solutions (containing 0.80 M OH- and 0 M, 0.01 M and 0.45 M HS- ) by means of electrochemical techniques. …
Impact Of Water Content On The Performance Of Alkali-Activated Slag Concretes, Susan A. Bernal, John L. Provis, Jannie S.J. Van Deventer
Impact Of Water Content On The Performance Of Alkali-Activated Slag Concretes, Susan A. Bernal, John L. Provis, Jannie S.J. Van Deventer
International Conference on Durability of Concrete Structures
In this study, we report the effect of varying the water/binder (w/b) ratio on the performance of sodium silicate activated concretes. Compressive strength development and water transport properties of these concretes were assessed, along with their resistance to carbonation. The results demonstrate that varying the water content within a reasonable range induced negligible changes in the compressive strengths of these concretes, when a constant paste content was used. A direct correlation between the w/b ratio and the amount of permeable voids in the concretes was not identified. The carbonation behaviour of these concretes changes prominently depending on the CO2 concentration …
Internal Curing By Sap In Ultra-High Strength Concrete With Cement-Silica Fume-Fly Ash Binder, Jianhui Liu, Caijun Shi, Xianwei Ma
Internal Curing By Sap In Ultra-High Strength Concrete With Cement-Silica Fume-Fly Ash Binder, Jianhui Liu, Caijun Shi, Xianwei Ma
International Conference on Durability of Concrete Structures
Super-absorbed polymer (SAP) is an effective internal curing materials for reducing autogenous shrinkage and improving cracking resistance of ultra-high-strength concrete (UHSC). This study investigated the compressive strength, shrinkage properties of UHSC with cement–silica fume–fly ash binder. The composition of the binder was designed using seven-batch factorial design method. The relationships between the binder composition and the properties were expressed in contours. Results showed that, silica fume could improve the compressive strength and total shrinkage of UHSC. However fly ash reduced the compressive strength and total shrinkage of UHSC to certain extent. On the other hand, under the internal curing of …
Design Of Ternary Blend High-Volume Fly Ash Concrete Mixes Using Hydrated Lime, Chamila Gunasekara, David Law, Sujeeva Setunge
Design Of Ternary Blend High-Volume Fly Ash Concrete Mixes Using Hydrated Lime, Chamila Gunasekara, David Law, Sujeeva Setunge
International Conference on Durability of Concrete Structures
The increase of carbon emission due to annual growth of Portland cement (PC) production has enforced research into the development of sustainable green concrete using a range of readily available industrial waste materials. The present study is focused on developing two high volume fly ash (HVFA) concretes with cement replacement levels 65% (HVFA‒65) and 80% (HVFA‒80). Initially, the required lime for both HVFA concrete mixes were determined, and then the optimized mix design identified, based on 28-day strength, by varying the fly ash‒lime combination. The optimized mixes achieved a compressive strength of 53MPa and 40MPa, for HVFA‒65 and HVFA‒80 concretes, …
Compressive Strength, Free Expansion And Shrinkage Of Expansive Concrete Containing Fly Ash, Warangkana Saengsoy, Rachot Chatchawan, Somnuk Tangtermsirikul
Compressive Strength, Free Expansion And Shrinkage Of Expansive Concrete Containing Fly Ash, Warangkana Saengsoy, Rachot Chatchawan, Somnuk Tangtermsirikul
International Conference on Durability of Concrete Structures
This study is aimed to investigate effect of fly ash on compressive strength, free expansion and shrinkage of expansive concrete. High CaO and low CaO fly ashes are used in this study. The replacement percentages of total binders by fly ash are 0 and 30% by weight. The replacements of expansive additive are 0, 20 and 30 kg/m3 of concrete. The test results revealed that the use of fly ash especially the high CaO fly ash can enhance expansion of expansive concrete at early age. The use of fly ash also reduces shrinkage at long term of the expansive …
Carbonation In Alternative Cementitious Materials: Implications On Durability And Mechanical Properties, Prasanth Alapati, Kimberly E. Kurtis Dr.
Carbonation In Alternative Cementitious Materials: Implications On Durability And Mechanical Properties, Prasanth Alapati, Kimberly E. Kurtis Dr.
International Conference on Durability of Concrete Structures
Understanding the rate and implications of carbonation on strength and durability in alternative cementitious materials (ACMs) is critical in designing ‘green’ concretes for intended service lives. In this paper, three commercially available ACMs, including one calcium aluminate cement (CAC), one calcium sulfoaluminate belite cement (CSA), and one alkali-activated binder using class C fly ash (AA), were evaluated against one portland cement (OPC). Thermogravimetric analysis (TGA) and x-ray diffraction (XRD) techniques were used to understand the effect of carbonation on ACM paste composition. Water sorption tests on both carbonated and uncarbonated cement mortar showed a significant reduction in porosity of this …
Effects Of Temperature And Curing Duration On The Stability Of Slag Cements In Combined Chloride-Sulphate Environments, Joseph Onah Ukpata, P. A. M. Basheer, Leon Black
Effects Of Temperature And Curing Duration On The Stability Of Slag Cements In Combined Chloride-Sulphate Environments, Joseph Onah Ukpata, P. A. M. Basheer, Leon Black
International Conference on Durability of Concrete Structures
This experimental study investigates the effects of temperature and curing duration on the stability of slag blended cement systems exposed at 20 °C and 38 °C to combined sodium chloride (30 g/L) – sodium sulphate (3 g/L) solutions. Two slags, designated as slag 1 and 2, having CaO/SiO2 ratios of 1.05 and 0.94, were respectively blended with Portland cement CEM I 52.5R at 30 wt.% replacement level. Mortar prisms and cubes with w/b ratio of 0.5 and binder/aggregate ratio of 1:3 were then prepared for length and mass changes. The samples were cured in lime water for either 7 …
Impact Of Chemical Compositions On Mechanical Properties Of Modified Asphalt Binders, Mohammad Nazmul Hassan
Impact Of Chemical Compositions On Mechanical Properties Of Modified Asphalt Binders, Mohammad Nazmul Hassan
Student Theses and Dissertations
Modified asphalt binders offer better mechanical performance in field conditions. According to many researchers, nanoclay modified asphalt binders can be a cheaper alternative of currently practiced polymer modified binders. The primary purpose of this study was to observe any changes in asphalt chemistries due to nanoclay modification and explore any correlations that may exist between chemical compositions and mechanical properties. Changes in chemical fractions were found to be source variant. Insoluble Asphaltene contents were observed to increase significantly after aging, whereas the Saturate contents decreased. Correlations were observed between mechanistic properties and chemical compositions. Moreover, aggregate-binder compatibility evaluation showed nanoclay …
Power Law Growth And Delayed Feedbacks In Socio‐Hydrological Systems, Anthony J. Parolari, Gabriele Manolia
Power Law Growth And Delayed Feedbacks In Socio‐Hydrological Systems, Anthony J. Parolari, Gabriele Manolia
Civil and Environmental Engineering Faculty Research and Publications
Water infrastructure dynamics result from coupled social and physical hydrological processes embedded in “socio‐hydrological systems” (SHSs). Freshwater fuels socioeconomic activity, which in turn exerts pressure on water resources through increased water demand and water quality degradation. Many factors emphasize the need for quantitative tools to predict the future of these systems, including SHS failures due to growing water scarcity from population growth and climate change. However, unfolding the interactions between social and hydrological factors continues to resist theoretical treatment, impeding progress toward a predictive framework. To resolve this issue, we propose and evaluate time delays as surrogates for the social …
Participatory Sensing-Based Geospatial Localization Of Distant Objects For Disaster Preparedness In Urban Built Environments, Hongjo Kim, Youngjib Ham
Participatory Sensing-Based Geospatial Localization Of Distant Objects For Disaster Preparedness In Urban Built Environments, Hongjo Kim, Youngjib Ham
Civil and Environmental Engineering and Engineering Mechanics Faculty Publications
Although the benefit of participatory sensing for collecting local data over large areas has long been recognized, it has not been widely used for various applications such as disaster preparation due to a lack of geospatial localization capability with respect to a distant object. In such applications, objects of interest need to be ro- bustly localized and documented for supporting data-driven decision-making in site inspection and resource mobilization. However, participatory sensing is inappropriate to localize a distant object due to the absence of ranging sensors in citizens' mobile devices; thus, the localization accuracy varies to a large extent. To address …
Stormwater Management Actions Under Regulatory Pressure: A Case Study Of Southeast Wisconsin, Walter M. Mcdonald, Joseph Naughton
Stormwater Management Actions Under Regulatory Pressure: A Case Study Of Southeast Wisconsin, Walter M. Mcdonald, Joseph Naughton
Civil and Environmental Engineering Faculty Research and Publications
In the United States, new legislation has given regulatory authorities greater oversight of municipal stormwater management programs. However, estimating the impact of greater oversight on municipal actions is difficult due to the uncertainty in current compliance efforts and their associated costs. This paper seeks to fill this gap through a case study of NPDES stormwater runoff permit reports from municipalities in Southeast Wisconsin. Specifically, this study evaluates the reported actions and expenditures against socioeconomic variables to identify the relationships between cost, socioeconomics, and the best management practices (BMPs) used for compliance. Results indicate that there are distinct differences between municipalities …
Strengthening Of Concrete Deep Beams With Extreme Discontinuities Using Near-Surface Mounted Composites, Moustafa Seifeddin Mansour
Strengthening Of Concrete Deep Beams With Extreme Discontinuities Using Near-Surface Mounted Composites, Moustafa Seifeddin Mansour
Civil and Environmental Theses
Installation of a web opening that fully interrupts the natural load path in concrete deep beams produces regions of extreme discontinuities and reduces the shear strength. This research examined the effectiveness of using near-surface-mounted carbon fiber-reinforced polymer (NSM-CFRP) reinforcement to restore the shear strength of deep beams with extreme discontinuities. The strut-and-tie model (STM) procedures were utilized to develop three different strengthening solutions around the discontinuity regions. A total of eight deep beam specimens (150 x 500 x2700 mm) with a shear span-to-depth ratio of a/h = 0.8 were constructed and tested. One beam was solid. Seven beams had a …