Large rupture strain fiber-reinforced polymer (LRS-FRP)-confined concretes are increasingly used in safety–critical infrastructure due to their high ductility and load-carrying capacity; however, accurate prediction of compressive strength (CS) in non-circular sections remains challenging due to non-uniform confinement induced by geometric irregularities, which limits the reliability of existing empirical models and design codes developed mainly for circular sections. To address this limitation, this study develops a reliability-oriented, data-driven framework that combines Bayesian-optimized ensemble machine learning, model interpretability, and uncertainty quantification. Six algorithms including random forest (RF), extremely randomized trees (ERT), extreme gradient boosting (XGBoost), histogram based gradient boosting (HistGBM), light gradient boosting machine (LightGBM) and categorical boosting (CatBoost) were trained using an experimental database of 174 non-circular LRS-FRP-confined concrete specimens. Model interpretability was achieved using Shapley additive explanations (SHAP), while predictive reliability was systematically evaluated through uncertainty-aware performance assessment. All models demonstrated strong generalization, with testing coefficients of determination (R
2
) ranging from approximately 0.96–0.99, and boosting-based methods consistently outperforming bagging approaches. CatBoost (testing R
2
≈ 0.985) exhibited the best overall performance, the lowest prediction errors, and the most reliable uncertainty estimates. Accordingly, the overall performance ranking was identified as CatBoost > HistGBM > XGBoost > ERT > LightGBM > RF. The results clearly indicate that high predictive accuracy alone is insufficient for reliable modeling of non-circular LRS-FRP-confined concrete and that uncertainty-aware evaluation is essential. SHAP-based analysis yielded physically consistent insights, identifying LRS-FRP thickness, unconfined concrete strength, and section corner radius as the dominant contributors to CS, while highlighting the critical role of post-transition LRS-FRP stiffness in sustaining effective confinement. Overall, the proposed framework offers an interpretable and reliability-aware alternative to conventional models and provides a robust predictive tool for engineering design and assessment of non-circular LRS-FRP-confined concrete.
An interpretable and uncertainty-aware machine-learning framework for estimating the shear capacity of FRCM-strengthened beams enables accurate, transparent, and uncertainty-aware assessment of shear capacity in FRCM-strengthened concrete beams.
Xiangsheng Liu, G. Figueredo, G. Gordon et al.· Journal of composites for co...· 0 citations
Among all ML models, eXtreme gradient boosting demonstrated superior predictive performance, effectively capturing the nonlinear and multivariate interactions governing confinement effectiveness.
Javad Shayanfar, J. Barros· Journal of Composites Scienc...· 0 citations
Accurate prediction of shear capacity in reinforced concrete beams is crucial for structural safety assessment. Conventional theoretical methods exhibit significant variability due to the complexity of shear failure mechanisms. This study presents an interpretable machine learning (ML) framework to enhance shear capacity prediction. A comprehensive database of 1175 beam specimens was developed, including normal concrete (NC) and ultra-high-performance concrete (UHPC) beams across three distinct cross-sectional geometries. The ML algorithms–support vector regression, artificial neural network, K-Nearest neighbors, decision tree, random forest, gradient boosting machine, light gradient boosting machine, adaptive boosting, categorical boosting, and extreme gradient boosting (XGBoost)–were optimized using 10-fold cross-validation and random search. The XGBoost algorithm demonstrated superior performance, achieving an R2 of 0.986 on the aggregated data set. Interpretability analysis with Shapley additive explanations identified beam depth (h), shear-span ratio (m), cross-sectional area (Ac) and fibre factor (λf) as critical features, highlighting their individual and interactive contributions. Moreover, a unified ML-based shear strength prediction model was developed that simultaneously captures the shear behaviour of both NC and UHPC beams, incorporating physically meaningful input features derived from the data set, thereby overcoming the limitations of separate empirical formulations. The proposed ML-based model significantly improved the accuracy of shear strength predictions compared to traditional empirical methods, enhancing reliability in structural design.
Qizhi Xu, Yan Tang, Shimin Ding et al.· Proceedings of the Instituti...· 0 citations
This study proposes an experiment-driven machine learning (ML) framework to address experimental limitations in estimating compressive strength within a controlled experimental domain of locally sourced fiber-reinforced concrete (FRC). Concrete mixes incorporating 1, 2, and 3% lathe scrap steel fibers were prepared using a standard 1:2:4 mix with brick chips as coarse aggregate. Due to practical constraints, intermediate fiber contents (e.g., 1.5% and 2.5%) were not experimentally cast. To overcome this limitation, supervised ML models were employed to interpolate compressive strength at fractional fiber dosages, thereby reducing experimental cost and time. A total of 48 experimental observations obtained from laboratory-tested cylindrical specimens were used to develop and evaluate four ML algorithms—Gaussian Process Regression (GPR), Artificial Neural Network (ANN), Support Vector Machine (SVM) and Random Forest (RF)—under a five-fold cross-validation framework. Among these, GPR exhibited the best performance among the evaluated models (R² = 0.884, RMSE = 1.647 MPa), effectively capturing the nonlinear relationship between curing age, fiber content, and compressive strength. SHAP-based interpretability analysis indicated that curing age is the primary governing factor in strength development, while fiber content contributes through secondary nonlinear effects. The results further indicate that moderate fiber inclusion improves compressive strength, whereas excessive fiber content may reduce performance due to workability loss, fiber clustering, and increased matrix heterogeneity. These findings are consistent with established concrete mechanics, where fiber reinforcement plays a more dominant role in tensile behavior than in compressive strength. The proposed framework demonstrates the capability of probabilistic ML models for accurate interpolation within controlled experimental conditions using high-quality laboratory data. This study provides a practical, data-driven approach for strength estimation and mix optimization of low-cost, locally sourced FRC, supporting sustainable construction practices and efficient utilization of industrial waste materials.
A comprehensive data-driven framework integrating ensemble machine learning models with systematic hyperparameter sensitivity analysis and explainable artificial intelligence techniques is proposed, demonstrating that the XGB model significantly outperforms the other approaches, achieving superior accuracy and robust generalization.
Qaim Shah, Waheed Ali Khoso, Fawad Iqbal et al.· Discover Artificial Intellig...· 0 citations