Civil and Environmental Engineering Commons^™

Effect Of Nano-Sio2 Content On The Setting Time And Mechanical Properties Of Tricalcium Silicate, Zhenhai Xu, Zonghui Zhou, Xin Cheng

International Conference on Durability of Concrete Structures

Using analytically pure calcium carbonate and silica as raw materials, high purity tricalcium silicate (C₃S) is prepared by solid-state reaction. The tricalcium silicate was sintered at a temperature of 1550°C with the heat preservation time of 6 h. The final sample needs three times of calcination circles. Ultrasonic cleaning machine was used to disperse the water and different amount of nano-SiO₂ (0, 1, 2, and 3 wt%) for 5 min, then mixed with C₃S, and formed into standard blocks. The setting time and compressive strength of each age (1, 3, 7, and 28 days) was …

Effects Of Nano-Caco3 On The Properties Of Cement Paste: Hardening Process And Shrinkage At Different Humidity Levels, Yamei Cai, Pengkun Hou, Zonghui Zhou, Xin Cheng

International Conference on Durability of Concrete Structures

The hardening process and volume stability of cement pastes with and without nano-CaCO₃ (NC) were studied through investigations on the setting time and shrinkage. Results showed that NC shortened the setting time of cement paste: the initial setting time decreased by 3.9 and 11.1% when 1 and 3% NC were added, and the finial setting times were shortened by 6.2 and 15.2%, respectively. The shrinkage of cement paste was compensated by NC, and the effect was more obvious as more NC was added into the cement paste. Although the shrinkage decreased at the lower relative humidity, the degree of …

Effect Of Bfrp Grid On Crack Propagation Of Reinforced Concrete Beam With Thick-Cover Concrete, Li-Juan Cheng, Hua-Nan He

International Conference on Durability of Concrete Structures

For the purpose of solving the problem of large crack width in concrete beam with thick cover, BFRP grid is added to the concrete cover to control the crack development and to improve the distribution status of cracks. In this paper, the bending tests under four-point loading are adopted to investigate cracking properties of reinforced concrete beams with thick cover, in which BFRP grid is added. During test cracking load, crack width and the number of crack were recorded, which will be analysed later. Test results show that crack development of reinforced concrete beam with thick cover can be effectively …

Effect Of Pet Wrapping On Shear Performance Of Corroded Reinforced Concrete Columns, Dawei Zhang, Yuxi Zhao, Weiliang Jin, Tamon Ueda

International Conference on Durability of Concrete Structures

In this paper, an experimental study is presented on the influence of PET warping on shear performance, such as diagonal shear cracking load, peak load, and energy dissipation of RC columns with stirrup corrosion before strengthening. The experimental program involved an electrochemical process to accelerate the migration of chlorides from an external electrolyte into the tested columns, a wetting–drying cycle process with a controlled current to speed up the corrosion of the stirrup in the tested columns, the strengthening of corroded columns with PET warping, and a pseudostatic test to determine the shear capacity of the tested beams. The shear …

Effect Of Cured Time On Creep Of Lightweight Aggregate Concrete, Hongzhi Cui, Haibin Yang, Xiaoxiao Xu, Zitao Lin, Tommy Yiu Lo

International Conference on Durability of Concrete Structures

Creep and shrinkage are such properties that will occur in concrete when they are under load and exposed to surrounding. Since this property will cause deformation which may decrease the design strength of the concrete, it is necessary to do have more knowledge on this phenomenon. So, we will study the effect of creep on 7 and 14 days of cured time of specimens which sealed or unsealed will be considered, respectively. The specimens have shown how the concrete strains when they are under sustained load with time. Besides, the sealed specimens have shown how the basic creep is different …

Application Of Raman Spectroscopy For Tracing The Status Of Silica Fume In Cementitious Materials, Yanfei Yue, Yun Bai, Jing Jing Wang

International Conference on Durability of Concrete Structures

Silica fume (SF) is an important component for manufacturing high performance concrete (HPC), owing to its superb pozzolanic reactivity and physical filling effects. However, application of SF in concrete may cause potential hazards issues. Although using SF in slurry form can somehow reduce the potential biotoxicity, the long-term stability and status of the SF particles within cementitious materials is still uncertain. In the current study, attempts were made to use Raman spectroscopy as an innovative alternative technique for tracing and identifying the status of SF both in its original SF slurry and in a 6-month-old hydrated cement paste. Light-optical microscope …

Delayed Ettringite Formation In Fly Ash Concrete Under Moist Curing Conditions, Zhuqing Yu, Jian Ma, Hu Shi, Xiaodong Shen, Guang Ye

International Conference on Durability of Concrete Structures

During the hydration of cement, tricalcium aluminate (C₃A) reacts with gypsum and forms ettringite (AFt). Once all gypsum is consumed, ettringite can further react with remaining C₃A and form monosulfate (AFm) at 1–2 days. Normally, at early ages, ettringite all transfers to AFm phase. After several months or years, ettringite can form again if a new source of sulfate becomes available in the pore solution of the paste, viz. delayed ettringite formation. In previous study, it was found that delayed ettringite forms in Portland cement concrete when the concrete samples were cured under moist conditions, …

Study On The Disposition Of Water In Fly Ash-Based Geopolymers Using Atr–Ir, Jian Liu, Yuan Fang, Obada Kayali

International Conference on Durability of Concrete Structures

This paper addresses the question of whether the main product of low calcium fly ash-based geopolymer is a hydrate, namely, sodium aluminosilicate hydrate (N-A-S-H). The answer to this question is important for understanding geopolymer characteristics. One of these is its fire resistance. In this study, fly ash-based geopolymers were synthesized using the combination of Na₂CO₃ and Ca(OH)₂. Samples were cured at ambient temperature for 7 days, then placed in the oven at 105°C for 24 h, and then calcined at 1050°C for 48 h. IR was used to examine the produced geopolymers at each stage …

Micromechanical Modeling For Material Design Of Durable Infrastructural Materials: The Influence Of Aggregate And Matrix Modification On Elastic Behavior Of Mortars, Sumanta Das, Amit Maroli, Narayanan Neithalath

International Conference on Durability of Concrete Structures

This paper reports the fundamental difference in microstress distributions in traditional hardened cement paste with quartz inclusions and a cement paste with lightweight aggregate (LWA) inclusions using microstructurebased numerical simulation involving finite element method with periodic boundary conditions. Variation of relative stress distributions under varying component material properties and varying microstructural features in both the systems is elucidated for a comprehensive understanding. The presented microstructure-based numerical technique accurately captures the stress concentrations inside microheterogeneous systems, which is otherwise not detectible using analytical homogenization schemes. Numerical simulations reveal that strengthening and stiffening of matrix and interfacial transition zone (ITZ) with silica …

Research On Concrete Durability Improving For Existing Island-Building And Its Application, Mao Jianghong, Zhu Yaofeng, Xu Fangyuan, Jin Weiliang, Xu Yidong, Chen Xu

International Conference on Durability of Concrete Structures

China’s coastal cities contain a large number of islands with abundant human activities, in which buildings are in a typical marine corrosion environment and the corrosion of reinforced concrete structures is very prominent. This paper makes research work on two aspects: (1) the durability assessment and durability improvement after a thorough investigation of the architecture of Xiangtan County, Ningbo city, on an island and (2) the application research of the bidirectional electromigration rehabilitation (BIEM) technology to enhance the durability of existing island building life. This paper designs a set of BIEM equipment based on solar power supply and develops a …

Chloride Penetration In Surface-Treated Concrete In Natural And Accelerated Environments, Jianfeng Dong, Yuxi Zhao, Shaoliang Pu, Ming Ji

International Conference on Durability of Concrete Structures

This study investigated the chloride penetration of surface-treated concrete in natural and accelerated environments. A part of a real concrete port, including the beams and the columns, was investigated. Concrete specimens cast together with the concrete port were transported to the lab and subjected to wetting and drying cycles for accelerating the ingression of chloride ion. Chloride concentration of the specimens in the lab and the components in situ was tested. The results show that the surface treatments obviously slow down the chloride penetration into the concrete in both lab and in situ. The chloride penetration in situ is …

Hierarchical Life-Cycle Design Of Concrete Structures, Zhujun Wang, Jin Weiliang, Ju Chen

International Conference on Durability of Concrete Structures

Concrete structures’ service life lasts decades. In order to deal with all the probable degradations and deteriorations in the whole life span, the concept of concrete structures’ Life-Cycle Design was introduced into China in the 1980s. However, until this day, Life-Cycle Design is still more of a concept to most structure designers and engineers, rather than a practical method. This paper provides a hierarchical method for concrete structures’ Life-Cycle Design, in which the design process is divided into five levels. Safety should be the fundamental requirements for all concrete structures, so as to guarantee a reliable quality. For structures located …

Study Of Water Permeability Of Lightweight Concrete, Xiaoxiao Xu, Haibin Yang, Hongzhi Cui, Zitao Lin, Tommy Yiu Lo

International Conference on Durability of Concrete Structures

The relationship between water permeability and different levels of the tested layers from the top surface to the bottom surface of the lightweight concrete specimens is determined in this study. It is beneficial to develop the design criteria for a durable lightweight concrete. The water permeability coefficient K of the samples was determined by water permeability test using GWT. It is found that the water permeability coefficient K of the three layers in each set of samples tends to decrease as the level of the tested from the top surface increase. Larger Rebound Number and higher density in the bottom …

Influence Of Sio2@Pmhs On The Water Absorption Of Cement Mortar As A Surface Treatment Agent, Ran Li, Pengkun Hou, Zonghui Zhou, Xin Cheng

International Conference on Durability of Concrete Structures

In this paper, the core–shell structured SiO₂@PMHS hybrid nanoparticles were synthesized with tetraethoxysilane (TEOS) and polymethylhydrosiloxane (PMHS). And SiO₂@PMHS core–shell nanoparticles were first used as a surface treatment agent for cement-based materials. The influence of SiO₂@PMHS nanoparticles on the water absorption of hardened cement mortar with water-to-cement ratio of 0.6 was investigated. Results showed that the water absorption of cement mortar treated with SiO₂@PMHS nanoparticles was decreased by 93.47% in comparison to the control sample.

Edge Detection Of Concrete Mesostructure Based On Dis Operator, Bin Feng, Zicheng Xu, Jin Xia, Shijie Jin, Weiliang Jin

International Conference on Durability of Concrete Structures

Aggregate edge detection is the basis of creating concrete mesoscale model, which is applied to analyze concrete mesoscale characteristics. A concrete digital image edge detection method using DIS operator is presented in this paper. Mean filter, multi-scale filter, and Gaussian filter are compared on the effect of concrete image noise reduction. Based on the result, Gaussian filter is the most optimum method to reduce image noise and remain aggregate edge distinct. Sobel operator, Laplacian operator, and DIS operator are applied respectively to detect the aggregate edge on Gaussian filter processed images. Based on the experiment, DIS operator outperforms other two …

Influence Of The Surface Treatment Of Hardened Cement Mortar With Colloidal Nano-Silica And Teos, Pengkun Hou, Xin Cheng, Zonghui Zhou

International Conference on Durability of Concrete Structures

Two types of silicate material, tetraethoxysilane (TEOS) and colloidal nanoSiO2 (CNS), were applied for surface treatment of hardened cement mortar by exploring their filling and pozzolanic reactivity to make the surface compacter. Results showed that the water adsorption coefficient, the water vapor transmission rate, and the water penetration depth were reduced when CNS and TEOS were applied onto the surface of hardened cement mortar, and TEOS exhibits a superior effect on surface treatment, making the mass-transport rate and extent smaller than CNS does.

Performance Of Concrete Patch Repairs: From A Durability Point Of View, Choorackal Avirachan Eldho, Ominda Nanayakkar, Jun Xia, Steve Jones

International Conference on Durability of Concrete Structures

Chloride contamination in reinforced concrete leads to the corrosion of steel bars. Concrete patch repairs are widely practiced as a remedial measure for the mitigation of such corrosion in reinforced concrete structures. The performance of the patch repairs was studied by various researchers in the past. The structural and material aspects of patch repairs have received more attention than the electrochemical consequences of patch repairs in past studies. But electrochemical changes could be the underlying cause for the failure of many patch repairs. This paper reviews the performance of patch repairs from a durability point of view. It covers the …

Aggregate Shape Effect On Multicomponent Ionic Electromigration In Concrete, Qing-Feng Liu, Long-Yuan Li, Jian Yang

International Conference on Durability of Concrete Structures

This paper presents a numerical study on the mechanism of chloride migration in concrete. Unlike most of existing work, this study utilises multicomponent ionic transport models to reflect the influence of ionic interactions by coupling both mass conservation and Poisson’s equations. A series of 2-D, 3-phase models with different shapes and volume fractions of aggregates are developed to simulate the chloride migration test. Through a comparatively overall numerical exploration that considers external voltage, ionic interactions, heterogeneous nature, ITZ, and ionic binding, some important features about multispecies coupling and aggregate shape effect, which have not been properly reported from existing concrete …

Effectiveness Of Vacuum Saturation Preconditioning Regime For Assessing Water Permeability Of High Performance Concrete, Kai Yang, Muhammed Basheer, Changhui Yang, Yun Bai, Adrian Long

International Conference on Durability of Concrete Structures

Saturating high performance concrete (HPC) for assessing water permeability is a challenge. This paper reports a testing program established to determine the reliability and efficiency of an in situ preconditioning regime, the vacuum saturation, for the water permeability test. The vacuum saturation regime was examined through changing the parameters used and to justify if the field conditioning regime is able to yield similar results as in the laboratory, the results after vacuum saturation were statistically analysed and compared with that after incremental immersion. Its accuracy was further examined by additional experiments, whereas factors considered include different concrete mixes and different …

Research On Chloride Penetration Resistance Of Hybrid Fiber Reinforced Self-Compacting Concrete, Wu-Jian Long, Zhe-Ming Mai, Jin-Guang Shi, Tian-Tian Zhao, Wu-Lei Peng

International Conference on Durability of Concrete Structures

The properties of chloride penetration of hybrid fiber reinforced self-compacting concrete (SCC) were investigated in this study. The results show that, the chloride penetration resistance of concrete can be improved by single incorporation either carbon or cellulose fibers. The concrete chloride diffusion coefficient D_RCM of 12-cm length carbon SCC with fiber content of 1.7 kg/m³, 2.72 kg/m³, and 3.4 kg/m³ decreases by 10.3%, 25.5%, and 18.2% compared to reference concrete without any fibers, respectively. Moreover, the concrete chloride diffusion coefficient D_RCM of cellulose SCC with fiber content of 1.2 kg/m³, 1.6 …

Corrosion Of Steel In Concrete And Its Prevention In Aggressive Chloride-Bearing Environments, Luca Bertolini, Maddalena Carsana, Matteo Gastaldi, Federica Lollini, Elena Redaelli

International Conference on Durability of Concrete Structures

This keynote paper deals with the durability of reinforced concrete (RC) structures exposed to aggressive environments characterized by high concentration of chloride ions, namely, marine environments or the use of de-icing salts. The mechanism of chloride-induced corrosion of steel in concrete is introduced, and its influence on the service life of RC structures is analyzed. Factors affecting the time to corrosion initiation are described with regard to both concrete properties and environmental exposure conditions. Design approaches available for achieving durability targets associated with the design service life are analyzed, focusing on studies carried out by the authors in recent years …

Moisture And Temperature Effects On Interface Mechanical Properties For External Bonding, Tamon Ueda, Justin Shrestha, Khuram Rashid, Dawei Zhang

International Conference on Durability of Concrete Structures

In order to develop rational guidelines for strengthening by external bonding, it is necessary to clarify longterm performance of interfacial bonding property. In this paper, moisture effects on bonding properties at FRP–concrete interface and temperature/moisture effects on bonding properties at PCM–concrete interface are presented. Shear bond strength of FRP–concrete interface is affected by moisture because resin–concrete adhesion strength is affected by moisture. Among tested CFRP external bonding systems, wet-layup CFRP systems all show the strength reduction, while prefabricated CFRP systems all show the strength increase after immersion. The bond stress–slip relationship and interfacial fracture energy also change, which can explain …

Pursuing Vision Zero In Seattle – Results Of A Systemic Safety Analysis, Rebecca Sanders

PSU Transportation Seminars

Many cities are considering pursuing Vision Zero to eliminate traffic deaths, but may not know how to move beyond addressing past crash locations toward preventing future crashes. Systemic analysis, which looks at crash patterns to determine common characteristics associated with various types of crashes, shows promise in helping cities to identify problematic locations and treatments in the hopes of preventing future crashes.

This presentation will share results from part of Seattle’s Vision Zero effort – a multi-phased analysis of pedestrian and bicycle crash data aiming to help the City understand both where crashes have occurred and where they are most …

Cee Team Won Weau Competition | Civil And Environmental Engineering, Usu College Of Engineering

College of Engineering News

A team from USU competed against local university in Utah and won the annual Water and Environment Federation of Utah (WEAU) Student Design Competition on Friday April 29 in St. George.

Aqueous Photochemistry Of Glyoxylic Acid, Alexis J. Eugene, Sha-Sha Xia, Marcelo I. Guzman

Chemistry Faculty Publications

Aerosols affect climate change, the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. While the formation of secondary organic aerosols (SOA) from gas phase precursors is relatively well understood, studying aqueous chemical reactions contributing to the total SOA budget is the current focus of major attention. Field measurements have revealed that mono-, di-, and oxo-carboxylic acids are abundant species present in SOA and atmospheric waters. This work explores the fate of one of these 2-oxocarboxylic acids, glyoxylic acid, which can photogenerate reactive species under solar irradiation. Additionally, the dark thermal aging …

Env 601 A New Method For Converting Sewage To Energy Using Self-Sustaining Smouldering, Tarek L. Rashwan

Canadian Society for Civil Engineering

A major challenge in designing resilient infrastructure is to meet the needs of sustainable development . Sustainable development requires a high degree of energy efficiency. Municipal wastewater treatment plants (WWTPs), in particular, have the potential to be much more sustainable.

Ccfss Special Edition Technical Bulletin Summer 2016, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Crp 463: University Area Multi-Modal Access Plan June 2016, William Riggs, Sam Anderson, Spencer Johnson, Garrett Wank, Alex Hunt, Lauren Leedeman, Roberto Contreras, Mark Manha, Emma Petersen, Rebecca Wysong, Shannon Boston, Augustus Grochau, Matthew Wiswell, Jerome Wu, Crp 463 Senior Project Professional Practice

City and Regional Planning Studios and Projects

This study outlines work completed as a part of the CRP 463 senior capstone class outlining a new, comprehensive approach to active transportation on the Cal Poly campus. Led by Dr. William Riggs the project assessed the current conditions, identified opportunities and constraints and then developed conceptual options for a campus active transportation plan. In addition to this process the plan involved completion of a draft Bicycle Friendly University application for the Cal Poly campus (included as a supplemental file) and envisioned conceptual design options for various locations on the campus. Key locations evaluated included the Perimeter Road / University …

แนวทางการนำบทเรียนการพัฒนาด้านการขนส่งทางถนนของสหภาพยุโรป มาประยุกต์ใช้กับไทยและอาเซียน, จักรกฤษณ์ ดวงพัสตรา

Journal of Transportation and Logistics (TRANSLOG)

การเปิดตลาดการขนส่งทางถนนระหว่างประเทศในสหภาพยุโรปเป็นส่วนหนึ่งของแผนการ รวมกลุ่มเศรษฐกิจประเทศสมาชิกสหภาพยุโรปที่ได้รับประโยชน์จากการเปิดตลาดบริการขนส่งทาง ถนน เป็นประเทศขนาดเล็กที่สามารถบริหารต้นทุนประกอบการและค่าจ้างแรงงานได้ถูก ประเทศไทย และอาเซียนไม่สามารถนำบทเรียนจากสหภาพยุโรปมาใช้ได้ทั้งหมด แนวทางที่เป็นไปได้สำหรับไทยใน การส่งเสริมการขนส่งทางถนนระหว่างประเทศควรเริ่มจากการจัดทำความตกลงด้านการขนส่งในกรอบ อนุภูมิภาคและทวิภาคี ประเด็นที่ต้องให้ความสำคัญ ได้แก่ การสร้างมาตรฐานให้เป็นแบบเดียวกัน ด้านข้อกำหนดทางเทคนิค น้ำหนัก ขนาดรถ ความปลอดภัย คุณสมบัติของผู้ประกอบการขนส่งและ ผู้จัดการการขนส่ง พิธีการศุลกากร หลังจากนั้นค่อยทำ การเจรจาแบบค่อยเป็นค่อยไปในประเด็นที่มีความ สำคัญอื่นๆ ได้แก่ การกำหนดโควตารถบรรทุก เส้นทางอนุมัติ การอำนวยความสะดวกทางการขนส่ง และการค้า การติดตามและตรวจสอบสินค้า การประกันภัยบุคคลที่สามและการประกันภัย การขนส่ง สินค้าผ่านแดน และการขนส่งต่อเนื่องหลายรูปแบบ

กรอบการพิจารณาประเภทอุตสาหกรรมที่เหมาะสมกับพื้นที่ชายแดน จากโครงสร้างพื้นฐานและปัจจัยการผลิต, ธนวัฒน์ เดชปรอท, จิตติชัย รุจนกนกนาฏ, สุมาลี สุขดานนท์

Journal of Transportation and Logistics (TRANSLOG)

บทความนี้เสนอการทำกรอบการพิจารณากิจกรรมทางเศรษฐกิจที่มีความเหมาะสมกับพื้นที่ ชายแดน โดยการใช้เกณฑ์เชิงปริมาณเพื่อประเมินศักยภาพของอุตสาหกรรมและพื้นที่ แบ่งเป็นสี่ขั้น คือ 1. การประเมินเบื้องต้นเพื่อหาประเภทอุตสาหกรรมและพื้นที่ที่คาดว่ามีความเหมาะสมจากข้อมูล ทุติยภูมิและสัมภาษณ์ผู้เชี่ยวชาญในพื้นที่ โดยพิจารณาจากปัจจัยการผลิต (วัตถุดิบ ที่ดิน แรงงาน) โครงสร้างพื้นฐานและสาธารณูปโภค (ถนน, ทางรถไฟ, ท่าเรือและท่าอากาศยาน, ไฟฟ้า, ประปา, โทรคมนาคม) รวมทั้งระยะทางจากพื้นที่ถึงด่านพรมแดน และความสอดคล้องกับธุรกิจในปัจจุบัน และแผนงานจังหวัดด้วย ซึ่งเป็นการคัดกรองอุตสาหกรรมและพื้นที่ในระดับอำเภอ 2. การลงพื้นที่ เพื่อทำการสัมภาษณ์ผู้เชี่ยวชาญเพื่อให้คะแนนปัจจัยต่างๆ จนกระทั่งได้พื้นที่อำเภอและอุตสาหกรรม ที่น่าสนใจเบื้องต้น 3. การวิเคราะห์ละเอียด โดยพิจารณาจากประเด็นข้างต้นตามลักษณะของห่วงโซ่ อุปทานของแต่ละอุตสาหกรรม ร่วมกับการสำรวจความคิดเห็นของนักธุรกิจและประชาชนในพื้นที่ โดย ถ่วงน้ำหนักคะแนนจากความคิดเห็นของผู้เชี่ยวชาญของแต่ละอุตสาหกรรม และ 4. การวิเคราะห์ชนิด อุตสาหกรรมในภาพรวมโดยลดความซ้ำซ้อนให้เหลือพื้นที่ที่พร้อมที่สุดในการจัดตั้ง เพื่อง่ายต่อภาครัฐ ในการผลักดันส่งเสริมและบริหารจัดการพื้นที่ได้อย่างเต็มประสิทธิภาพ กรอบการพิจารณานี้ ภาครัฐ สามารถนำมาใช้ในการคัดกรองอุตสาหกรรมที่เหมาะสมสำหรับพื้นที่ชายแดนที่ภาครัฐกำลังพัฒนา สร้างอุตสาหกรรมและเขตเศรษฐกิจพิเศษเพื่อรองรับประชาคมเศรษฐกิจอาเซียน โดยมีการนำเสนอ ตัวอย่างการประยุกต์ใช้ในพื้นที่จังหวัดมุกดาหารและนครพนม