Digital Commons Network^™

Computational Modelling Of 3d Mesostructure Of Recycled Aggregate Concrete, Yi Ding, Gert Van Der Heijden, Mingzhong Zhang

International Conference on Durability of Concrete Structures

Recycled aggregate concrete (RAC) has a complex mesostructure with heterogeneous compositions of aggregates, interfacial transition zones (ITZs), and mortar. It is still a big challenge to simulate the 3D mesostructure of RAC accounting for its inherent characteristics, which plays a crucial role in its mechanical properties and long-term durability. This study introduces an advanced computational framework based on Voronoi tessellation approach to generate the highly realistic 3D mesostructured of RAC. The proposed framework can address the key challenges in simulating irregular aggregate morphology and spatial distribution while effectively incorporating the multi-phase structure of RAC which consists of old and new …

Evaluation Of Ionic Behaviours Under Electric Field With Integrated Chemo-Electric Numerical Platform, Kai Matsutani, Zhao Wang, Yuya Takahashi, Tetsuya Ishida

International Conference on Durability of Concrete Structures

Chloride ion plays a critical role in terms of steel corrosion for reinforced concrete structures, which leads to structural degradation. To investigate the macro-cell corrosion and mechanical deterioration, an integrated chemo-electric numerical platform has been developed with spatial-averaged modelling of steel and concrete. The verification of macro-cell circuit in structural concrete induced by applied charge has been achieved, while the ionic behaviors under impressed charge evaluated by this platform remains unverified. This study numerically investigates the ionic behavior of chloride under both ponding and electrophoresis conditions with the integrated platform. Comparison between numerical simulation and available experimental data shows the …

Exploring Aerial Additive Manufacturing With Cementitious Materials Using Autonomous Drones, Richard James Ball, Barrie Dams, Paul Shepherd, Binling Chen

International Conference on Durability of Concrete Structures

Aerial additive manufacturing (AAM) represents a novel approach to construction by enabling untethered autonomous unmanned aerial vehicles (UAVs, or drones) to deposit cementitious materials in mid-flight, overcoming geometric and accessibility limitations associated with ground-based additive manufacturing. This study presents research to investigate the structural viability of cementitious mixes tailored for aerial extrusion, focusing on rheological optimisation, mechanical performance, and deposition feasibility. Pseudoplastic behaviour was achieved through the use of hydrocolloids, enabling low viscosity under shear for extrusion while rapidly stiffening post-deposition to maintain layer geometry. Fibre reinforcement and inorganic fullerene tungsten disulphide (IF-WS₂) nanoparticles were incorporated to enhance flexural strength, …

Deploying 3d Concrete Printing For Large-Scale Building Construction In Saudi Arabia: A Case Study, Zakiah Yousif Altehaini, Mohammed Ahmad Dayili, Meshari Ali Alrajab, Adel Nasser Alharbi, Ali Khudhran Alutaibi, Eyad Hamzah Garatly

International Conference on Durability of Concrete Structures

This paper details the successful large-scale implementation of 3D concrete printing (3DCP) for the construction of large building in remote area of Saudi Arabia. As one of the first religious buildings in the region constructed using additive manufacturing, this project showcases 3DCP's technological and environmental potential for contemporary building. In order to ensure sustainability and cost effectiveness, the mosque was constructed using a COBOD BOD2 gantry printer and a customised concrete mix made up of 99% locally sourced materials and 1% CEMEX D-fab admixture. To maximise thermal insulation and accommodate mechanical, electrical, and plumbing (MEP) systems, the structure included a …

Microstructure Characterisation Of Alkali-Activated Fly Ash-Slag Paste At Elevated Temperatures, Wenlin Tu, Mingzhong Zhang

International Conference on Durability of Concrete Structures

Alkali-activated fly ash-slag (AAFS) cured at ambient temperature has been considered as a promising eco-friendly alternative to traditional cement-based binders, offering reduced carbon emissions and enhanced durability. However, understanding how these materials respond to extreme conditions, particularly at high temperatures, remains a critical area of study. Therefore, it is essential to investigate this material for ensuring their reliability in fire-prone and high-temperature environments. This paper presents a systematic experimental study on microstructural and damage evolution in AAFS paste exposed to elevated temperatures (from 20 °C to 800 °C) in terms of changes in phase assemblage and pore structural characteristics as …

Static Compressive Behaviour Of A Novel Functionally Graded 3d Re-Entrant Lattice Reinforced High Performance Concrete, Yiwei Xuan, Mingzhong Zhang, Dianwei Gao

International Conference on Durability of Concrete Structures

This study systematically studies the static mechanical properties of high-performance concrete (HPC) reinforced with a 3D re-entrant lattice structure, considering the effect of functionally gradient design. The uniform 3D re-entrant lattice (U) and the corresponding vertically positively and negatively graded lattices (FG1 and FG2) were designed and manufactured with 3D printing. The plain HPC (P-HPC) and HPC reinforced with U (U-HPC), FG1 (G1-HPC) and FG2 (G2-HPC) were fabricated accordingly. Static compressive tests were then conducted to investigate the static compressive behaviour of 3D re-entrant lattice and corresponding lattice reinforced HPC. Results indicate that all 3D re-entrant structures exhibit clear NPR …

Impact Of Sulfate Activation Of Slag Cement On The Performance Of Coarse Recycled Aggregate Concrete, Md Ikramullah Khan, V Vinayaka Ram

International Conference on Durability of Concrete Structures

The global construction industry is facing increasing pressure to adopt sustainable practices, driving the search for alternatives to conventional concrete. This research investigates the development of eco-friendly concrete by replacing virgin coarse aggregates with recycling plant-based coarse recycled aggregates (CRAs) and utilising Portland slag cement (PSC). While PSC-CRA based concrete offers environmental advantages, it typically exhibits lower early-age strength and durability, limiting its practical application. To address these limitations, a systematic experimental study was conducted to evaluate the efficacy of sodium sulfate (Na2SO4) as a chemical activator to the binder. This research comprehensively assessed the impact of the activator on …

Recent Advances In Geopolymer Feedstocks Activation For Sustainable Cement Production, Oluyemi Kehinde, David J. Hughes, Emeka H. Amalu, Dali Bondar

International Conference on Durability of Concrete Structures

The growing environmental and safety issues posed by human activities have underlined the importance of Ordinary Portland Cement production, which is a major contributor to carbon dioxide emissions that impede Net Zero goals. The urgent need to produce cement substitutes with reduced carbon footprints has prompted research on geopolymers formed from industrial mineral wastes. These materials provide promising sustainable development solutions, but the selection of appropriate activation methods remains a significant constraint to their widespread industrial and economical application. A systematic review using the PRISMA protocol included 302 recent and relevant papers, identifying four principal activation strategies and their combinations …

Influence Of Printing Speed And Nozzle Size On Buildability Of 3d Printed Concrete Walls: A Nonlinear Finite Element Study, Auliagitta Kumala Apsari, Asdam Tambusay, Priyo Suprobo, Benny Suryanto

International Conference on Durability of Concrete Structures

The increasing adoption of additive manufacturing in construction necessitates robust simulation frameworks capable of capturing the time-dependent mechanical behaviour of fresh concrete. This study examines the influence of printing speed and nozzle size on the buildability of infilled concrete walls using finite element (FE) simulations. A nonlinear fracture-plastic constitutive model was employed to simulate the time-dependent mechanical behaviour of fresh concrete, with the modelling framework first validated against previously published experimental data to ensure reliability. Subsequently, six wall configurations were analysed, incorporating nozzle diameters of 30 mm and 40 mm, and printing speeds of 20, 30, and 40 mm/s. The …

Steel Fibre Reinforced Self-Compacting Geopolymer Concrete Structural Members, Jubilant Nyasha Chidziya, Chikako Fujiyama

International Conference on Durability of Concrete Structures

Geopolymer concrete (GPC) is an innovative and sustainable alternative to ordinary Portland cement concrete (OPC) for structures in seismic prone areas owing to tough and ductile performance due to strong bond with steel reinforcement. However, the application of GPC in construction projects is low due to limited understanding of the long-term performance of structural members. The objective of this study is to examine the effects of steel fibres on the flexural properties of self-compacting geopolymer concrete (SCGC) and OPC beams. The study involved investigation of the fresh and mechanical properties of concrete. Structural parameters such as toughness, and ductility index …

Surface Morphology, Bond Strength And Failure Behaviour Of Steel Vs Basalt Rebars In Alkali Activated Concrete, Ansu Mary Alex, Sreejith Nanukuttan, Adeline Mccartney, Marios Soutsos, Daniel Mcpolin

International Conference on Durability of Concrete Structures

This microscopic characteristics of basalt bars after exposure to alkaline solutions and pullout performance of steel and basalt rebars embedded in conventional and alkali-activated concrete were studied. The overarching goal is to assess the potential of basalt rebars as an alternative to conventional steel reinforcement in alkali activated concrete elements. To understand their durability in alkaline environments, especially within alkali-activated concrete (AAC), steel and basalt rebars were subjected to an accelerated exposure test in high-pH simulated concrete pore solutions, for 24hrs. This aimed to replicate the aggressive internal environment typically found in AAC and mixes with supplementary cementitious materials. Post-exposure …

Durability Performance Of 3d-Printed Ultra-High Strength Concrete Incorporating Corrosion Inhibitor, Jyotish Kumar Das, M. Mirza Abdillah Pratama, Behzad Nematollahi, Maurizio Guadagnini

International Conference on Durability of Concrete Structures

This paper reports preliminary results on the durability performance of a 3D-printed ultra-high strength concrete (3DP-UHSC). A nitrite-based compound was added at varying dosages (0%, 2%, and 4% by mass of binder) to the developed 3DP-UHSC as a corrosion inhibitor. The effects of the corrosion inhibitor on the workability of fresh mixes and the mechanical properties (compressive and flexural strengths in various directions) of the 3DP-UHSC mixes were studied. Furthermore, the durability performance of the 3DP-UHSC was assessed by conducting porosity, water absorption, and chloride permeability measurements. Mould-cast specimens were also prepared and tested for comparison purposes. The results indicated …

Editorial, Joseph P. Hupy, Mary M. Fink

Journal of Aviation Technology and Engineering

Editorial for JATE 13.2.

Editorial, Joseph P. Hupy, Mary M. Fink

Journal of Aviation Technology and Engineering

Editorial for JATE 13.1.

Reference At A Remote Field Station: A Case Study Of Ecology, Environmental Science And Geology Fieldwork At An Embedded Library, Thomas Gerrish

Libraries Faculty and Staff Scholarship and Research

Purpose Field station libraries, particularly those serving biological and marine research stations, represent a unique but understudied class of special libraries. This case study investigates reference services at the remote University of Michigan Biological Station (UMBS) to provide a baseline assessment of how such services support the information needs related to research in ecology, geology and environmental science.

Design/methodology/approach The study recorded, coded and analyzed 209 reference transactions from the 2022 and 2023 summer sessions, revealing trends in patron inquiries and the role of the reference desk. Further, the case study examined the organizational structure, community interaction and mission of …

“If I Ruled The World”: Deploying Spatial Imaginaries For Examining Anti-Blackness And Space In Precollege Engineering Education, Christopher Wright, Monet V. F. Harbison

Journal of Pre-College Engineering Education Research (J-PEER)

Engineering’s systemic exclusion of Black people has been a decades-long inquiry. While critical race theory and community cultural wealth have been utilized to examine anti-Blackness in precollege engineering education, critical geographies have been underutilized. This essay contends that the deployment of a spatial imaginaries lens could be used to expand understandings of the spatial imaginary of anti-Blackness in the discipline. Using historical and contemporary data from an engineering high school as well as nonpositivist ways of knowing, the essay contends that examining spatial realities and underpinnings are opportune provocations for redefining purposes, assumptions, and values in precollege engineering education.

Public Perceptions Of Universities As Public Entities During The Covid-19 Pandemic Era, Jinho Jung, Laura Barrett, Nicole Olynk Widmar, Mario Ortez

Department of Agricultural Economics Faculty Publications

Higher education institutions are facing challenges in navigating social, cultural, and political issues. The online presence of higher education presents a new set of opportunities and challenges; knowledge, news, and continuing education are increasingly disseminated online. Additionally, the public, student bodies and stakeholders are increasingly looking at reviews or seeking opinions via online and social media to form opinions on institutions. This analysis uses online and social media to analyze and compare perceptions of two public universities in Indiana, namely Purdue University and Indiana University. These two Indiana institutions are located in the same state, allowing for comparisons of public …

Challenging The School Boundaries: Exploring Challenges And Opportunities In Homeschooling Engineering Education, Luis Montero-Moguel, Cynthia Lima, Guadalupe Carmona, Verónica Vargas-Alejo

Journal of Pre-College Engineering Education Research (J-PEER)

Homeschooling sparks controversy regarding the quality of education when compared to the traditional schooling system. However, homeschooling rates have doubled nationwide since the pandemic, especially among minorities. Funding and curricular material resources may be limited for homeschooling families, especially those from diverse backgrounds. Therefore, this essay discusses the need to expand the current boundaries of engineering education to include homeschooling communities. Drawing from our homeschooling experience, we present three recommendations that respect the cultures and unique characteristics of homeschooling to promote engineering practices in these communities. Our proposal challenges negative perceptions of homeschooling, enhancing our understanding of its unique characteristics …

The Synergy Between Sfrc And Structural Steel In Increasing The Ductility Of Composite Structures, Gonzalo Ruiz, Ángel De La Rosa, Vaibhav W. Masih, Riccardo Zanon

C3 Symposium 2025

Our research on the compressive behavior of steel-fiber reinforced concrete (SFRC) led to a constitutive model in Annex L ofthe new Eurocode 2. This recognition piqued the interest of ArcelorMittal, who requested that we explore the implications of increased compression ductility for composite structures, particularly beams with embedded structural steel sections. The findings from this research demonstrate that the compressive ductility of SFRC enables us to fully utilize the tensile capacity of structural steel in composite structures, resulting in unprecedented levels of structural ductility.

Fiber Reinforced Concrete Composites - Seminal Contributions Of Surendra Shah, Vellore S. Gopalaratnam, Wengui Li

C3 Symposium 2025

The authors review the scholarly contributions of Surendra P. Shah during a prolific six-decade academic career in fiber reinforced concrete composites. This compilation includes discussions on often cited seminal publications encompassing experimental mechanics, analytical modeling, the development of test standards, materials characterization and innovations in the science of fiber reinforced concrete (FRC) materials. Collectively, these contributions have greatly improved our insights on how the nano- and micro-mechanics of such composites and processing techniques affect the macroscopic performance of creatively engineered reinforced cement composites. Starting with his Ph.D. the first contribution to understanding the inelastic behavior and fracture of concrete, the …

Fresh And Mechanical Properties Of The Ultra-High-Performance Concrete With Cellulose Nanofibers, Xiaoli Xiong, Chengcheng Tao, Kamal H. Khayat

C3 Symposium 2025

Water-sensitive cellulose significantly impacts the performance of the ultra-high-performance concrete (UHPC), leading to variations in its fresh and mechanical properties of fresh and hardened concrete materials. In this study, the cellulose nanofibers, a more environmentally friendly class of nanomaterials, are introduced into UHPC. The rheological and mechanical properties of UHPC are investigated, including viscosity, yield stress and compressive strength. The results reveal significant effect of cellulose nanofibers on the properties of UHPC in terms of material performance and sustainability. Advanced characterization techniques, including isothermal calorimetry, thermogravimetric analysis (TGA), and X-ray diffraction (XRD) are employed to study the effect of cellulose …

Upcycled Medical Hemp Fibers For Enhancing Tensile Strength And Fire Resistance Of High-Strength Concrete, Ahmed Almaadawy, Liahneli Knowles, Abigail Lazier, Srishti Banerji, Zach Haber, Bruce Bugbee

C3 Symposium 2025

This research investigates fire and tensile resistance of high-strength concretes employing fibers extracted from waste medical hemp stalks. Environmental impact analysis of hemp-based solutions is also considered.

Hempcrete As Low Carbon Solution For Thermal Retrofitting Of Buildings, Rotem Haik, Dor Lazar, Alva Peled

C3 Symposium 2025

Thermal mortars are developed with hemp shives and pozzolans for thermal retrofitting of cultural heritage buildings, including concrete architecture from the 50s. The goal is to improve the thermal performance of the building, while reducing the carbon footprint. This research is within the framework of European Union’s Horizon 2020 (Sincere). A range of mixtures were developed based on standard mortar for plaster, as a reference. The research investigates the possibility of partly replacing the cement with pozzolans, as well as the sand in the mortar with fine hemp shives, to obtain lower EE and EC of the mixture, as compared …

Durability Of Sisal Fibers Reinforced Cement-Based Plates, Kaio Campos, Kíssila Goliath, L. Souza, F. Teixeira

C3 Symposium 2025

Sustainable materials have been gaining increasing attention in the construction sector due to their environmental advantages and the need for cost-effective solutions. An example of this is vegetable fibers, which are recognized as a sustainable and eco-friendly alternative for the reinforcement of cementitious composites in civil engineering applications. To contribute to our knowledge about the durability of these materials, this study investigated the mechanical behavior of cementitious plates reinforced with 5% long aligned sisal fibers materials after being subjected to accelerated aging. To improve the durability of the composite, 50% of the cement in matrix was replaced by 40% metakaolin …

Viability Of Waste Glass Powder In Inter-Ground Alkali Activated Cement, Andrew Callender, Xander Babcock, Thien Tran, Maria Juenger

C3 Symposium 2025

No abstract provided.

Recovery Of Silica As Scm From Olivine Using Oxalic Acid-Enabled Chemical Comminution, Jie Shi, Hongyan Ma

C3 Symposium 2025

Using supplementary cementitious materials (SCMs) to substitute cement or clinker, as a decarbonization strategy, is limited by the shortage of conventional SCMs like GGBS, fly ash, and silica fume. Meanwhile, mafic/ultramafic minerals are unlimited to be processed for SCMs production. In this study, oxalic acid is used to dissolve olivine ((Mg, Fe)2SiO4) to produce amorphous silica. Results show that high purity amorphous silica could be successfully obtained and the yield can be up to 93.42%. This process endows the extra value of olivine alongside being used for carbon storage.

Oxcem: A Novel Carbon-Negative Cement Based On Oxalic Acid And Steel Slag, Xing Cheng, Jihui Qin, Hongyan Ma

C3 Symposium 2025

The proper disposal of steel slag remains a challenging issue. This study explores a novel carbon-negative cement, utilizing the reaction between steel slag and oxalic acid. The mechanical properties, phase composition, and microstructure of OxCem were investigated through compressive strength tests, TG analysis, XRD, and MIP test. The results indicate that the optimal EAF/OA ratio is 3.5, achieving a 28-day compressive strength of 34.7 MPa. The strength enhancement of the paste is attributed to the influence of the reaction products, ferrous oxalate and calcium oxalate, on the pore structure.

Transforming Agricultural Residues Into High-Performance Scms Through Mechanochemical Activation, Dia Brown, Juan Pablo Gevaudan

C3 Symposium 2025

Despite the abundance of ashed agricultural residues and their potential as supplementary cementitious materials (SCMs), given a high silica content (up to 90 wt.%), their high water demand limits their use. This challenge compromises both the fresh-state workability and mechanical performance of supplemented concrete – a pivotal challenge for countries in the Global South with large agricultural sectors and low production of other industrial SCMs. To address this limitation, we investigate two innovative mechanochemical methods and their effects on the fresh-state workability issues of these ash-based SCMs. This presentation will share our latest results describing how the mechanochemical activation of …

Thermochemical Pre-Treatments On Corn Stover Ash To Boost Its Reactivity, P V P Moorthi, Zhihui Sun

C3 Symposium 2025

When treated properly, corn stover ash (CSA) is known to be an effective source of supplementary cementitious materials (SCM) for use in concrete. The influence of thermochemical pre-treatments on the reactivity of CSA was studied in this project. The result shows that acid pre-treatment was effective and necessary in the removal of organic and inorganic compounds from the corn stover. The pre-treatment conditions including type and concentration of acid used, temperature, pre-treatment duration, and the acid/ash (A/A) ratio are important factors that affect the reactivity of the final product. This study shows that a proper pre-treatment condition will lead to …

Hydrophobic Modification For The Design Of High-Performance And Ultra-High Performance Cementitious Composites, Iman Aghayan, Scott Muzenski, Reed T. Heintzkill, Marina I. Kozhukhova, Habib Tabatabai, Konstantin Sobolev

C3 Symposium 2025

This paper presents a novel method for designing high-performance and ultra-high-performance concrete (HPC/UHPC) through hydrophobic and nanomaterial modification. Three-dimensional hydrophobization of cementitious matrices is achieved by incorporating water-based emulsions of silico-organic compounds containing active hydrogen. The approach enables high-strength matrices with superior flexural performance via fiber reinforcement, further improved by uniformly distributed small air voids that promote multi-cracking and strain-hardening behavior. Incorporating aluminum oxide (Al₂O₃) nanofibers with 1% silica fume (or metakaolin) produces UHPC-grade strength and ductility while reducing chemical shrinkage and simplifying composition. Developed with Type V and I cements at W/CM < 0.3, the composites reached compressive strengths up to 195 MPa, exhibited high flowability, and showed excellent strain-hardening when reinforced with 2% synthetic macrofibers (PVA and HDPE), with HDPE yielding greater ductility. This synergy of hydrophobic modification, nanoengineered matrix, and synthetic fibers offers a cost-effective, sustainable alternative to conventional HPC/UHPC, exceeding durability and environmental performance benchmarks.