Automated Damage Detection of a Concrete Member using Image-based Displacement Fields and Topology Optimization
Presented By: Minsoo Sung
Affiliation: Ohio University
Description: Accurate and automated damage detection is critical for the effective Structural Health Monitoring (SHM) of concrete infrastructure. This study presents a novel framework for automated damage detection that integrates image-based displacement fields with a topology optimization for automated damage detection. The methodology employs a digital twin, represented by a Finite Element Model (FEM), where a damage parameter (?) ranging from 1.0 (intact) to 0.0 (damaged) is assigned to each element to characterize local elastic modulus. The optimization algorithm uses full-field displacement measurements under load as a target, iteratively updating the spatial distribution of the damage parameter to minimize the discrepancy between the digital twin’s predicted response and the experimental target values.
The framework was experimentally validated using a concrete beam with prescribed deteriorated zones subjected to a non-destructive four-point bending test (Fig.1a). Full-field surface displacements were captured using Digital Image Correlation (DIC) and served as the direct input for the optimization. The algorithm successfully generated a damage parameter map (Fig.1b) that accurately identified the location and geometry of the deteriorated regions. Furthermore, the digital twin’s predicted displacement and strain fields showed good agreement with the experimental measurements, correctly capturing strain concentrations around the damaged areas (Fig.1).
The calibrated digital twin provides a direct and quantitative means to evaluate the structural performance of the damaged/deteriorated concrete member, including assessing reduction in stiffness and elastic load-carrying capacity. The results demonstrate that this approach offers an efficient method for automated, non-destructive damage assessment in concrete structures.
From Steel to Synthetic: Unlocking the Potential of PVA and Carbon Fibers in Ultra High Performance Concrete
Presented By: Meghana Yeluri
Affiliation: Cleveland State University
Description: Ultra-high-performance concrete (UHPC) is widely recognized for its exceptional strength and durability, making it a preferred material for structural applications. However, the high cost and limited availability of steel fibers hinder its broader adoption. This study investigates the partial replacement of steel fibers with synthetic alternatives—polyvinyl alcohol (PVA) and carbon fibers (CF)—as a strategy to enhance sustainability and reduce material costs. Seven UHPC mixtures were developed with a total fiber volume of 1.5%, incorporating PVA and CF at steel fiber replacement levels of 0%, 33%, 50%, and 75%. All mixtures were proportioned to achieve a target flow of 8 ± 1 inches by adjusting the dosage of high-range water-reducing admixture, while maintaining a constant water-to-cementitious materials ratio of 0.20.
All mixtures met the target compressive strength of 17,500 psi under standard moist curing, with a maximum strength reduction of approximately 10% observed at the 75% replacement level. The modulus of rupture across all mixtures ranged from 1,450 to 2,300 psi. In contrast, the modulus of elasticity and splitting tensile strength declined by up to 5% and 40%, respectively, with increasing levels of synthetic fiber substitution. Notably, the inclusion of PVA fibers in combination with steel fibers proved effective in mitigating drying shrinkage, with a 32% reduction observed at 33% replacement level after 91 days. Additionally, Durability was assessed using sorptivity, rapid chloride permeability, and surface resistivity. Linear regression analysis revealed strong correlations among sorptivity, charge passed, and surface resistivity in UHPC mixtures containing synthetic fibers.
Decoding Mayan Lime Mortar: Role of in?situ Soil in Carbonation Kinetics
Presented By: Md Montaseer Meraz
Affiliation: Oregon State University
Description: The use of locally available materials, such as in situ soils, as fine aggregates in mortar offers a sustainable strategy for optimizing resource use in construction. Historically, the Mayan civilization used local soils to produce lime based mortars for infrastructure; the pyramids in Mexico stand as enduring examples of this practice, particularly the Muyil Pyramid (see Figure 1, top left), are surviving instances of this process. The long term stability of these structures underscores the durability of such materials. This study investigates the mineralogical characteristics of Mayan lime mortars, based on samples collected from the Muyil pyramid, built circa 300?B.C., in Quintana?Roo, Mexico. Specifically, X-Ray Diffraction (XRD), and Thermogravimetric analysis (TGA) of the mortar indicate that the mortar primarily comprises lime and calcareous soil sourced from nearby regions. Identical lime mortars were cast with the soil sources from the same region (as shown in Figure 1). The preliminary results indicate that the calcium carbonate polymorphs present in the soil played a critical role in the kinetics of carbonation. The high amounts of Aragonite and calcite in the in situ soil significantly enhance the carbonation kinetics and contribute to the strength improvement. The strength gain is attributed mainly to the binding of soil particles from calcium carbonate precipitation.
Flexural Behavior of Limestone Calcined Clay Cement Concrete in Reinforced Concrete Members
Presented By: Nikhil Potnuru
Affiliation: Genex Systems LLC
Description: Moderate- to low-purity calcined clay is an emerging alternative supplementary cementitious material (ASCM) that can serve as a replacement for traditional supplementary materials or be incorporated in the production of blended cements. Despite extensive research at the material level on the combined use with limestone to form limestone calcined clay cement, there is a notable lack of research investigating the structural behavior of reinforced concrete elements made with the material. This work investigated the flexural performance of mild steel reinforced beams, with and without primary reinforcement lap splices, fabricated using industrially produced calcined clays as ASCMs in portland limestone cement concretes. Mechanical characterization including compressive, tensile, and flexural strengths, and the modulus of elasticity were benchmarked against existing design code expressions. The flexural behavior of concrete beams including load-deflection response, ultimate capacity, failure modes, and cracking patterns was experimentally investigated. Key parameters affecting design were varied to study mechanical properties, flexural response, stress block behavior, and reinforcement development length. This study begins to address the critical gap in structural-level data for limestone calcined clay concrete, providing essential insights to inform the safe adoption into practice.
Performance of Polymer Concrete Beams Under Fire Exposure
Presented By: MANISH SAH
Affiliation: Michigan State University
Description: Growing interest in sustainable and durable construction materials has brought increased attention to polymer concrete as a promising alternative to conventional concrete. Known since the mid-20th century, polymer concrete offers high strength, low permeability, and improved durability due to the use of polymers as full or partial binders, making it suitable for structural and repair applications in aggressive environments. Recent research has focused on improving its mechanical and durability properties through optimized resin types, mix designs, and curing methods. However, limited studies have investigated its thermal and mechanical properties under fire at the material level, and the fire performance of structural members made from polymer concrete remains largely unexplored. This study addresses this gap by developing a finite element model in ABAQUS to simulate the fire behavior of polymer concrete beams. To simulate realistic fire behavior, the model incorporates mechanical loading, support conditions, and a time-temperature fire curve, along with temperature-dependent thermal and mechanical properties, enabling the evaluation of both thermal and structural responses under fire exposure. Based on defined failure criteria, the model predicts the fire resistance of polymer concrete beams, as illustrated in Figure 1.
Ultrafast Belite (ß-C2S) Production using Biofuel-Based Combusion Synthesis
Presented By: Shubham Agrawal
Affiliation: Arizona State University
Description: This study presents a novel low-temperature combustion synthesis (CS) approach for the rapid production of belite-rich cements. CS leverages the exothermic heat released from the combustion of biofuels such as lignin and/or biomass, intermixed with pelletized limestone and quartz. At an imposed furnace temperature of ~700°C (as opposed to 1200–1300°C required in a conventional kiln), the source materials are rapidly transformed to belite, resulting in energy, emissions, and economic benefits. This work explores the influence of various process parameters, viz., fuel types and contents, airflow rate, porosity, holding temperature, and holding time on the efficiency of CS-based belite synthesis. Through careful optimization of these parameters, including through machine learning
based methods, > 90% belite content is obtained in the synthesized pellets. Advanced analytical tests show that the belite produced from CS closely resembles that obtained from traditional high-temperature processing. CS has the potential to reduce energy consumption and emissions associated with belite production significantly, and to accelerate the synthesis process by three-to-four times as compared to the conventional method.