JOURNAL OF CLEANER PRODUCTION, cilt.558, ss.1-20, 2026 (SCI-Expanded, Scopus)
The transition toward low-carbon and environmentally responsible construction materials has amplified the
importance of biochar-modified cementitious composites (BMCC), which provide long-term carbon sequestration
due to the stable retention of biogenic carbon. However, predicting the compressive strength (CS) of BMCC is
challenging because mixture components—especially biochar-related properties—interact in nonlinear and nonmonotonic
ways. Such complex behavior limits the applicability of traditional empirical correlations and illustrates
the importance of advanced artificial intelligence (AI)-based modeling. This paper develops an explainable
AI-guided framework using four base learners and ten stacking machine-learning (ML) models to estimate the CS
of BMCC based on a curated dataset of 482 instances compiled from 26 independent studies. Among the evaluated
model configurations, the SM-8 stacking model, integrating Extreme Gradient Boosting (XGB), Random
Forest (RF), and Extra Trees Regressor (ETR) base learners, achieved the highest predictive accuracy, yielding
superior test-phase performance with R = 0.972, R2 = 0.945, RMSE = 3.90, MAE = 2.68, and MAPE = 7.84%.
Explainability analyses using SHAP and ICE identified age, w/c, cement, SP, and biochar characteristics as the
dominant factors influencing CS, while also highlighting nonlinear relationships and optimum-performance regions
for critical parameters. In addition, cradle-to-gate life-cycle carbon footprint and production cost indicators
were quantified to support sustainability-oriented mixture assessment. To enhance practical accessibility, a userfriendly
tool was developed, enabling real-time predictions, guided parameter ranges, model selection, and
simultaneous reporting of environmental and economic indicators. Overall, the proposed explainable AI
framework enables accurate BMCC mix optimization, supporting sustainable construction and practical engineering
decision-making.