Open research questions in Innovative concrete reinforcement materials

What the literature leaves open

• One of the challenges is the difficulty in understanding the internal structural changes at the microscale that occur in composite concrete materials. Another challenge is the lack of standard protocols for testing the tensile strength of concrete mixtures with varying levels of rubber and steel fiber content.

  Experimental Study on Macroscopic and Microscopic Tensile Strength Characteristics of Steel-Fiber-Reinforced Rubber Concrete · 2026 · DOI

• It highlights the need to balance computational efficiency with the accuracy of the simulation results.

  The effect of external force on the thermal and mechanical behavior of glass fiber reinforced concrete panels using molecular dynamics simulation · 2026 · DOI

• Further studies could investigate the effect of other factors on the thermal and mechanical behavior of the composite. The study of the composite's behavior under different environmental conditions could be explored. The development of more complex models that include minor constituents could be a future research direction.

  The effect of external force on the thermal and mechanical behavior of glass fiber reinforced concrete panels using molecular dynamics simulation · 2026 · DOI

• Lack of a unified framework governing the reclamation and reuse of concrete, metals, plastics, and timber in new construction. Limited understanding of the flexural behavior of concrete beams containing tire-recycled steel fibers and reinforced with reused steel.

  Flexural Behavior of Concrete Beams Containing Tire-Recycled Steel Fibers and Reinforced with Reused Steel · 2026 · DOI

• Evidence remains limited for direct comparisons of untreated, alkali-treated, and hornified fibers across the same length-content matrix. The study aims to address this gap by examining one fiber-free C40 concrete and 27 fiber-reinforced conditions.

  Effects of Fiber Length, Content, and Surface Treatment on the Compressive and Flexural Response of Date Palm Fiber-Reinforced Concrete · 2026 · DOI

• The calculation of crack initiation toughness needs to account for the effect of initial crack height, - The crack initiation toughness for specimens without pre-existing cracks (α = 0) cannot be calculated. The fracture toughness of rubber concrete was constrained by the applicable range of each theory.

  Fracture Behavior Assessment of Rubberized Concrete Using Non-Standard Specimens: Experimental Investigation and Model Optimization · 2025 · DOI

• The environmental impact of traditional concrete production is a significant challenge to the sustainability of the construction industry. There is a need to reduce the carbon footprint of concrete while maintaining or enhancing its performance. The effects of different fibers on high-performance concrete incorporating zeolite are not well understood.

  Impact of Fibers on the Mechanical and Environmental Properties of High-Performance Concrete Incorporating Zeolite · 2025 · DOI

• Enhancing the damping capacity of concrete while maintaining its other desirable properties is a challenge. Optimizing fiber content and mechanical properties to increase concrete's damping capacity is a complex task. The study identifies the need for further research to develop high-damping concrete composites.

  Damping Behavior of Fiber-Reinforced Concrete: A Comprehensive Review of Mechanisms, Materials, and Dynamic Effects · 2025 · DOI

• Need for robust predictive models that can generalize across various material and reinforcement variations.

  Predicting and Unraveling Flexural Behavior in Fiber-Reinforced UHPC Through Based Machine Learning Models · 2025 · DOI

• The study had a limited number of specimens (12 for each mixture). The study did not consider other factors that may affect the properties of polymer-modified concrete.

  Mechanical and Impact Strength Properties of Polymer-Modified Concrete Supported with Machine Learning Method: Microstructure Analysis (SEM) Coupled with EDS · 2025 · DOI

• The complexity of the composite materials and the need for accurate prediction of their elastic moduli. The limited availability of experimental data for training and testing the FNN model. The need to account for large-scale manufacturing defects and strength properties essential for analyzing failure and damage tolerance.

  Predicting the Elastic Moduli of Unidirectional Composite Materials Using Deep Feed Forward Neural Network · 2025 · DOI

• The existing methods for calculating elastic moduli have limitations. There is a need for a more accurate and efficient method for predicting the elastic moduli of unidirectional composites. The current models do not account for large-scale manufacturing defects and strength properties essential for analyzing failure and damage tolerance.

  Predicting the Elastic Moduli of Unidirectional Composite Materials Using Deep Feed Forward Neural Network · 2025 · DOI

• The lack of studies on the use of coral sand as a substitute for conventional aggregates in ultra-high performance concrete preparation. The need to investigate the effects of different fibers on the mechanical properties of coral sand ultra-high performance concrete.

  Effect of Polyethylene and Steel Fibers on the Fracture Behavior of Coral Sand Ultra-High Performance Concrete · 2025 · DOI

• The need for a comprehensive evaluation of different UHPC shear resistance models. The lack of a utilization tensile stress prediction equation for the FHWA method.

  Performance Evaluation of Current Design Models in Predicting Shear Resistance of UHPC Girders · 2025 · DOI

• The study aims to address this gap by investigating the effects of steel fiber volume content and electrification duration on mechanical properties and corrosion mechanisms.

  Corrosion Characteristics and Strength Degradation Mechanism of Metro Steel Fiber-Reinforced Cementitious Materials Under the Low-Carbon Target · 2025 · DOI

• The research involves only eighteen types of ECC with different mix ratios. The study does not provide a comprehensive comparison with other types of cementitious composites. The cost reduction of fibers is limited to 24.3%. The experimental average crack spacing at the ultimate state can be calculated by Equation (6).

  High-Performance Cementitious Composites with Tensile Strain Capacity Up to 18% · 2025 · DOI

• Further research is needed to explore the causes of UHTCC’s ultra-high tensile strain. The new constitutive model needs to be verified to be applicable to more types of UHTCC. The effect of fiber type, specimen size, loading mode, and high temperature on tensile properties of ECC needs to be further studied. The application of UHTCC in engineering fields needs to be further explored.

  High-Performance Cementitious Composites with Tensile Strain Capacity Up to 18% · 2025 · DOI

• Lack of published articles on the rheology of ultra-high-performance concrete with a multi-scale approach. Limited understanding of the effect of cement type, supplementary cementitious materials, and water-to-binder ratio on UHPC rheology.

  Multi-Scale Experimental Investigation of UHPC Rheology: From Cement Paste to Fiber-Reinforced Mortar Scale · 2025 · DOI

• The size and uniformity of the speckles on the specimen surface can significantly influence the measurement accuracy of the digital image correlation method. The study needs to address the challenge of quantifying the effects of basalt fibers on the damage behavior of foam concrete.

  Statistical Analysis of Tensile Damage of Basalt Fiber Foam Concrete Based on DBSCAN Clustering Method · 2025 · DOI

• The need to develop new lightweight composite building materials for floating structures. The lack of effective composite ECC with improved properties.

  Composite Reinforced Expanded Clay and Basalt Fiber Concrete for Floating Platforms · 2025 · DOI

• The lack of understanding of the effect of sulfate attack on the fatigue performance of concrete. The need for experimental and theoretical foundations for the application of hybrid fiber-reinforced rubber concrete in engineering structures.

  Experimental Study on the Cyclic Loading Behavior of Hybrid Fiber-Reinforced Rubber Concrete in Sulfate Environment · 2025 · DOI

• Limited deformability and reduced compressive toughness of traditional concrete. Difficulty in predicting the failure crack strength of polymer-modified concrete. Complexity of analyzing the microstructure of polymer-modified concrete mixtures.

  Mechanical and Impact Strength Properties of Polymer-Modified Concrete Supported with Machine Learning Method: Microstructure Analysis (SEM) Coupled with EDS · 2025 · DOI

• Shear thickening behavior in UHPC mixtures, which can affect their rheological properties. Particle-particle hydrodynamic interactions, which can dominate under high shear. Limited accuracy of the modified Bingham model in representing the observed curvature at higher shear.

  Multi-Scale Experimental Investigation of UHPC Rheology: From Cement Paste to Fiber-Reinforced Mortar Scale · 2025 · DOI

• Limited to 17 concrete mixtures, - No quantitative analysis of internal damage, porosity, or fiber-matrix bond strength, - No long-term durability tests under aggressive environments, - Small sample size for some mixture…

  Experimental Study on Macroscopic and Microscopic Tensile Strength Characteristics of Steel-Fiber-Reinforced Rubber Concrete · 2026 · DOI

• Investigating the effects of other factors on the corrosion of steel fiber-reinforced cementitious materials, - Exploring the use of different types of fibers or fiber combinations to improve corrosion resistance, - Developing more accurate models to predict the corrosion behavior of steel fiber-reinforced cementitious…

  Corrosion Characteristics and Strength Degradation Mechanism of Metro Steel Fiber-Reinforced Cementitious Materials Under the Low-Carbon Target · 2025 · DOI

Most-cited papers in Innovative concrete reinforcement materials

• New development of ultra-high-performance concrete (UHPC) · Composites Part B Engineering · 2021 · 922 citations
• Predicting concrete compressive strength using hybrid ensembling of surrogate machine learning models · Cement and Concrete Research · 2021 · 686 citations
• Machine learning prediction of mechanical properties of concrete: Critical review · Construction and Building Materials · 2020 · 659 citations
• Durability of ultra-high performance concrete – A review · Construction and Building Materials · 2020 · 650 citations
• Efficient machine learning models for prediction of concrete strengths · Construction and Building Materials · 2020 · 525 citations
• Review of ultra-high performance concrete and its application in bridge engineering · Construction and Building Materials · 2020 · 438 citations
• UHPC evolution, development, and utilization in construction: a review · Journal of Materials Research and Technology · 2020 · 408 citations
• Machine learning-based prediction for compressive and flexural strengths of steel fiber-reinforced concrete · Construction and Building Materials · 2020 · 401 citations
• Seawater sea-sand engineered/strain-hardening cementitious composites (ECC/SHCC): Assessment and modeling of crack characteristics · Cement and Concrete Research · 2020 · 356 citations
• International Perspective on UHPC in Bridge Engineering · Journal of Bridge Engineering · 2020 · 344 citations

Most recent work

• Serpentine-induced synergistic enhancement of tensile strength and ductility in high-strength Engineered/Strain-Hardening Cementitious Composites (ECC/SHCC) · Cement and Concrete Composites · 2026
• Durability assessment of UHPC with varying steel fiber contents under sulfuric acid Attack: Macro-Micro characterization · Engineering Failure Analysis · 2026
• Machine learning models with monotonic constraints for predicting bond strength between reinforcing bars and UHPC · Structures · 2026
• Rate-dependent flaw effect and cracking behavior of Ultra-High-Strength Engineered Cementitious Composites (UHS-ECC) with seawater and sea-sand · Cement and Concrete Composites · 2026
• Study on the flexural performance of 4D steel fiber-reinforced concrete under freeze-thaw cycles · Construction and Building Materials · 2026
• Dynamic mechanical properties and a predictive DIF model of seawater-coral sand ECC: Effects of water-to-binder and sand-to-binder ratios · Construction and Building Materials · 2026
• Interfacial shear behavior between precast UHPC girder and cast-in-place NC slab with large groove and rebars · Structures · 2026
• Multi-objective design method of concrete mix ratio based on machine learning: forward prediction and reverse design · Archives of Civil and Mechanical Engineering · 2026
• Concrete Material Variability and Machine Learning Model Performance: A Comprehensive Review · Buildings · 2026
• Dynamic compressive behavior of ECC with PET fine aggregate: Experimental investigation and constitutive modeling · Construction and Building Materials · 2026

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