Civil and Environmental Engineering Commons^™

The Effect Of Relative Humidity On Eddy Covariance Latent Heat Flux Measurements And Its Implication For Partitioning Into Transpiration And Evaporation, Weijie Zhang, Martin Jung, Mirco Migliavacca, Rafael Poyatos, Diego G. Miralles, Tarek S. El-Madany, Marta Galvagno, Arnaud Carrara, Nicola Arriga, Andreas Ibrom, Ivan Mammarella, Dario Papale, Jamie R. Cleverly, Michael Liddell, Georg Wohlfahrt, Christian Markwitz, Matthias Mauder, Eugenie Paul-Limoges, Marius Schmidt, Sebastian Wolf, Christian Brümmer, M. Altaf Arain, Silvano Fares, Tomomichi Kato, Jonas Ardö, Walter Oechel, Chad Hanson, Mika Korkiakoski, Sébastien Biraud, Rainer Steinbrecher, Dave Billesbach, Leonardo Montagnani, William Woodgate, Changliang Shao, Nuno Carvalhais, Markus Reichstein, Jacob A. Nelson

Biological Systems Engineering: Papers and Publications

While the eddy covariance (EC) technique is a well-established method for measuring water fluxes (i.e., evaporation or 'evapotranspiration’, ET), the measurement is susceptible to many uncertainties. One such issue is the potential underestimation of ET when relative humidity (RH) is high (>70%), due to low-pass filtering with some EC systems. Yet, this underestimation for different types of EC systems (e.g. open-path or closed-path sensors) has not been characterized for synthesis datasets such as the widely used FLUXNET2015 dataset. Here, we assess the RH-associated underestimation of latent heat fluxes (LE, or ET) from different EC systems for 163 sites in …

Compaction Quality Assurance Specifications Of Unbound Materials, Beshoy Riad, Xiong Zhang, Jenny Liu, Yizhuang David Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Compaction quality control/assurance of unbound geomaterials is one of the crucial components in pavement and embankment construction to ensure their performance, stability, and sustainability. Conventional density-based methods such as nuclear density gauge to determine the compaction quality have been widely used due to the straightforward relationship between the readings and targeted material property. Recent modifications in construction standards and the introduction of the Mechanistic-Empirical Pavement Design Guide have inspired a growing interest in developing and implementing strength/stiffness-based compaction control quality assurance (QA) specifications. Numerous studies have been dedicated to investigating the efficiency and effectiveness of the stiffness-based compaction QA tools. …

Deep Learning To Predict The Hydration And Performance Of Fly Ash-Containing Cementitious Binders, Taihao Han, Rohan Bhat, Sai Akshay Ponduru, Amit Sarkar, Jie Huang, Gaurav Sant, Hongyan Ma, Narayanan Neithalath, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Fly ash (FA) – an industrial byproduct – is used to partially substitute Portland cement (PC) in concrete to mitigate concrete's environmental impact. Chemical composition and structure of FAs significantly impact hydration kinetics and compressive strength of concrete. Due to the substantial diversity in these physicochemical attributes of FAs, it has been challenging to develop a generic theoretical framework – and, therefore, theory-based analytical models – that could produce reliable, a priori predictions of properties of [PC + FA] binders. In recent years, machine learning (ML) – which is purely data-driven, as opposed to being derived from theorical underpinnings – …

Deep Learning To Predict The Hydration And Performance Of Fly Ash-Containing Cementitious Binders, Taihao Han, Rohan Bhat, Sai Akshay Ponduru, Amit Sarkar, Jie Huang, Gaurav Sant, Hongyan Ma, Narayanan Neithalath, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Fly ash (FA) – an industrial byproduct – is used to partially substitute Portland cement (PC) in concrete to mitigate concrete's environmental impact. Chemical composition and structure of FAs significantly impact hydration kinetics and compressive strength of concrete. Due to the substantial diversity in these physicochemical attributes of FAs, it has been challenging to develop a generic theoretical framework – and, therefore, theory-based analytical models – that could produce reliable, a priori predictions of properties of [PC + FA] binders. In recent years, machine learning (ML) – which is purely data-driven, as opposed to being derived from theorical underpinnings – …

Garden Improvements For "The Ranch", Ayden J. Cole

Construction Management

The Ranch spans over ten-and-a-half acres and provides employment opportunities for individuals with disabilities. The core focus of The Ranch is cultivating small crops and raising livestock, which are tended to and harvested by individuals with disabilities. The ultimate aim is to provide them with hands-on experience of working on a farm and how to take care of livestock and grow food. However, the existing property of The Ranch was not exactly what they wanted for their students' learning environment. The existing area where the crops were being grown was not fenced in so critters were getting into the garden …

Collaboration Between Science And Art Through A Special International Symposium For Ecosystem Health And Sustainability, Changwoo Ahn Dr.

The STEAM Journal

The collaborations between ecosystem restoration and art practices was epitomized by the eco-artist Jackie Brookner who said: “it is not a matter of the scientists providing the hard-core research and artists the soft outreach; rather, the dynamics engendered in the space between disciplines is full of information necessary to solve complex problems at the systemic level”. This paper reviews and summaries the goals, activities, and lessons learned from a special symposium, which was held at the 12^th INTECOL (International Congress of Ecology) conference in Beijing, China, August 21 through 25, 2017, where about 3000 people attended from 70 countries. …

Steam And Environmental Justice In An Interdisciplinary Context, Paula Farca, Alina Handorean, Jürgen Brune

The STEAM Journal

This course proposes an interdisciplinary perspective, envisions unique synergies between environmental justice concepts and STEAM projects on mining, and aims to solidify a foundation based on justice, equity, equality, and empathy for STEM students and faculty. Our (S)TEAM made of professors in three academic departments underscores interdisciplinary and diversity connections through an interdisciplinary team-taught course, units on environmental justice related to mining, teaching of literary texts, and STEAM projects. We also involved faculty, alumni, and our campus and city community through STEAM exhibits.

Gömböc The Great, Indigo M. Strickert, Lori E. Bradford

The STEAM Journal

A sonnet written about the mathematics behind the self-righting shape of some tortoise shells.

Enhancing Performance Of Gravity Driven Membranes For Water Purification In Small Rural Communities, Amr Ezzat Melligy Mr.

Theses and Dissertations

Due to the rapid population growth in Egypt, providing safe drinking water is becoming an ongoing challenge especially in rural scattered communities. It became more crucial than ever to find innovative and affordable solutions to purify water and reduce water-borne diseases. Ultrafiltration and micro-filtration membranes has been successful in large, centralized plants and is currently one of the popular solutions to provide high quality product water. However, using those membrane systems in rural areas is challenged by several parameters; among which are; the absence of skilled workers, stable energy sources and availability of chemicals. The goal of this thesis is …

Implications Of Good Faith In Construction Contracts, Nadine Rashed

Theses and Dissertations

The principle of good faith is making inroads and continues to significantly impact various contractual arrangements. In most civil legal systems, good faith is present as a core principle. Nevertheless, its definition is beyond doubt scarce in the construction industry. However, the common law lacks the good faith obligations. Good faith is one of the fundamental principles that impact the contractual obligations between the contracting parties. This paper creates an urge to address the implications of good faith on construction contracts in the pre-contract and post-contract award stages. Therefore, the paper’s objective is to propose a legal/contractual clause that meets …

Vr-Based Safety Training Program For High-Rise Building Construction, Sahar Badr

Theses and Dissertations

The rates of fatal and non-fatal accidents within the construction industry across the globe are surging despite the massive efforts that are being exerted toward maintaining a safe working environment. Past research has proved that the provision of effective safety training programs is a primary course of action that should be taken to minimize construction accidents, fatalities, and both fatal and nonfatal injuries.

However, in acknowledging the limitations of traditional safety training programs within the construction industry, several researchers have addressed the urge to incorporate novel training practices that are based on the modern virtual reality (VR) technology to promote …

Effects Of Wind Turbine Rotor Positioning On Tornado Induced Loads, Juan P. Lopez Ortiz

Electronic Thesis and Dissertation Repository

This study investigates the loads induced by a large-scale tornado simulation on a horizontal axis wind turbine (HAWT) to assess the influence of three-dimensional flows with respect to the HAWT position. The loads were analyzed under two rotor operational conditions, idling and parked, at five radial distances. Subsequently, experimental validation of the numerical code HIW-TUR was conducted by evaluating the induced moments for various yaw and pitch angles. The experimental results demonstrated that the bending moment was the most important in terms of magnitude and variation with respect to the HAWT position. Furthermore, The HIW-TUR code accurately identified the magnitude …

Spatial Data Analysis For The Development Of Expected Adverse Weather Charts For Transportation Construction Projects, S M Rahat Rashedi, Akosua Ofosua Okyere-Addo

SDSU Data Science Symposium

Problem - Seasonal and daily weather events impact construction projects across the various climate regions of South Dakota in differing fashions. Additionally, the impacts for similar weather events can impact grading, surfacing, and structural construction activities in various ways. Adverse weather conditions can cause major delays which may lead to time extensions and increase project cost.

Purpose – To address these issues, South Dakota Department of Transportation (SDDOT) developed Working Day Weather Charts in 1998. However, advances in construction practices and weather prediction as well as climatic changes have occurred over the interim 25 years. This study is focused on …

Spatial Data Analysis For Traffic Safety Network Screening, Akosua Okyere-Addo, S. M. Rahat Rashedi

SDSU Data Science Symposium

Problem - The roadway system represents a major investment, both public and private, and a valuable resource that enables mobility and accessibility to users. Due to degradation of aging infrastructure and increasing traffic, transportation agencies are seeking to effectively update or improve the system. With rising costs, tight budgets, and limited land resources, agencies are seeking effective techniques for identifying critical mobility and safety concerns. Historically, assignment of crashes to portions of the network, whether segments or intersections, has been the primary manner to link crash and road elements.

Purpose – The primary goal is to explore a potentially more …

Effect Of Additional Water Or Superplasticizer On Key Characteristics Of Cement Paste Made With Superabsorbent Polymer And Other Shrinkage Mitigating Materials, Kamran Aghaee, Ricarda Sposito, Karl Christian Thienel, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The use of superabsorbent polymer (SAP) coupled with expansive agent (EA) or shrinkage-reducing admixture (SRA) can effectively reduce shrinkage of cement-based materials. However, SAP particles at high contents can adversely affect rheological and mechanical properties. Securing proper workability can be accomplished by additional water or adjusting the superplasticizer (SP) demand. There is an uncertainty about the efficiency of these approaches to workability compensation. This study evaluates the effect of additional water or SP on key properties of cement paste made with SAP and relatively high content of EA or SRA. Macro and micro mechanisms underlying the effect of combined shrinkage …

Rheological Characterization Of Ultra-High Performance Concrete For 3d Printing, Arun R. Arunothayan, Behzad Nematollahi, Kamal Khayat, Akilesh Ramesh, Jay G. Sanjayan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The authors recently developed a 3D-printable ultra-high performance fiber-reinforced concrete (3DP-UHPFRC) for additive construction of structural members with significantly reduced reliance on steel bars. This study investigates the rheological behavior of the developed 3DP-UHPFRC. The effects of two major factors affecting the performance of 3DP-UHPFRC, namely steel fiber volume (0, 1%, and 2%) and nano-clay (NC) content (0, 0.1%, and 0.2% by binder mass) on workability, static yield stress, dynamic yield stress, and apparent viscosity were determined. Test results showed that the inclusion of steel fibers and NC reduced the workability and led to a significant increase in the static …

Homogeneous Flow Performance Of Steel-Fiber Reinforced Self-Consolidating Concrete For Repair Application: A Biphasic Approach, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, fiber-reinforced self-consolidating concrete (FR-SCC) was considered as a diphasic suspension of fiber and coarse aggregate (F-A ≥ 5 mm) skeleton in mortar suspension with solid particles finer than 5 mm. The coupled effect of the volumetric content of fibers, coarse aggregate particle-size distribution, and rheological properties of the mortar on the passing ability and dynamic stability of various FR-SCC mixtures was investigated. Nine high-strength and 10 conventional-strength FR-SCC mixtures for repair application were proportioned with water-to-binder ratios (W/B) of 0.35 and 0.42, respectively, and macro steel fibers of 0.1%–0.5% volumetric contents. The dosages of high-range water-reducer (HRWR) …

Behaviour And Material Properties Of Versaloc Semi-Interlocking Mortarless Masonry, Sonam Dorji, Hossein Derakhshan, David P. Thambiratnam, Tatheer Zahra, Alireza Mohyeddin

Research outputs 2022 to 2026

Masonry construction is popular around the world, but the use of mortared masonry presents numerous challenges. In recent decades, masonry construction systems incorporating interlocking masonry units have been proposed to eliminate mortar. The interlocking between masonry units can be achieved using specially shaped units. This paper presents a comprehensive experimental study to determine the behaviour as well as basic material properties of one such semi-interlocking mortarless masonry. The experiments included testings of ungrouted masonry units, prisms, and wallets. In addition, masonry prisms and wallets with grouted cores were also investigated to study the effect of grouting. A detailed description of …

Effect Of Class C And Class F Fly Ash On Early-Age And Mature-Age Properties Of Calcium Sulfoaluminate Cement Paste, Sukanta K. Mondal, Carrie Clinton, Hongyan Ma, Aditya Kumar, Monday Uchenna Okoronkwo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To Promote the Sustainable Development of Eco-Efficient Calcium Sulfoaluminate (CSA) Cements through the Partial Replacement of the CSA Clinker with Supplementary Cementitious Waste Products, the Effects of Coal Fly Ashes on the Early-Age and Mature-Age Properties of a Calcium Sulfoaluminate (CSA)-Based Cement Paste Were Investigated. the Impacts of Both Class C and Class F Fly Ashes on the Rheological Properties, Hydration Kinetics, and Compressive Strength Development of CSA Cement Paste Were Studied. Rheology-Based Workability Parameters, Representing the Rate of Loss of Flowability, the Rate of Hardening, and the Placement Limit, Were Characterized for the Pastes Prepared with Fixed Water-To-Cement (W/c) …

Evaluation, Comparison, And Improvement Recommendations For Caltrans Financial Programming Processes And Tools, Wenbin Wei, Nigel Blampied, Raajmaathangi Sreevijay

Mineta Transportation Institute Publications

The California Transportation Improvement Program System (CTIPS) is the main tool used by Caltrans’ Division of Financial Programming to support the business of transportation programming. It is a multi-agency joint-use project programming database system applied to develop and manage various state and federal transportation programming documents. The goal of this project is to evaluate CTIPS and explore various new options that will maintain the current functionality of CTIPS, meet legislative guidelines for ADA compliance, ensure security of the system, and have sufficient scalability and capabilities for integration with other systems in the future. The research is based on the review …