PSI - Issue 70

Saurav Kar et al. / Procedia Structural Integrity 70 (2025) 674–681

680

Fig. 4. Sample linear regression analysis conducted using one-way ANOVA

4. Conclusions

This current research work provides statistical interpretation for laboratory test results for concrete mixes with a new mix proportioning technique adopted. Regression analysis can be applied: (a.) to optimize mix proportions for cost and performance, (b) model carbonation depth and chloride penetration or drying shrinkage, (c) support sustainable design decisions in green construction. For this particular substitution of high-volume fly ash with cement, the resultant correlations represent a practical tool to target mechanical properties such as compressive strength for 28-days standard curing conditions. For the F ash substitution from 40%, 50%, 60% and 70% (cem:F ash 1:1), improved workability properties were obtained with increased chemical admixture content (~1 to 2%). Good correlation coefficient (R 2 ) values of 0.9831 or 98.3% are obtained at higher w/b ratios for 28-days curing. Trendline indicates the linear relationship with R 2 value of 0.9831 for higher w/b ratios and 0.974 for lower w/b ratios, suggests a strong negative correlation. This signifies, a better model fit. Higher R 2 values of 0.983 signifies, good model fit, while R 2 values of 0.843 shows 15.7% variance due other properties in concrete such as reduced pozzolanic activity and fly ash reactivity at higher fly ash content beyond 40% and low water-binder ratios. Lower standard deviation values show that the data set is closely tight. For better understanding of behaviour of mix proportion, multiple linear regression analysis can be conducted. Acknowledgements The authors would like to acknowledge Techno India University, Salt Lake, and West Bengal, India for providing technical and financial support to conduct all the experiments at Advanced Concrete Technology. Special appreciation is extended to undergraduate students of Department of Civil Engineering of Heritage Institute of Technology, Kolkata, West Bengal, India, for providing technical assistance. The authors also want to express gratitude towards doctoral student of Department of Civil Engineering, Techno India University, Salt Lake, West Bengal for participation in concrete production and specimen testing, and to the companies that provided material for this work; to FOSROC, India and SIKA, India for provision of chemical admixtures; Uttam Mondal for provision of class F fly ash from SKY Fly Ash bricks Pvt. Ltd., Madhyamgram, Badu, Kolkata, West Bengal, India. References Agwa, I.S., Ibrahim, O.M.O., 2019. Fresh and hardened properties of self-compacting concrete containing of cement kiln dust, Journal of Concrete Research Letters 10, 127-134. Al-Harthy, A.S., Taha, R., Al-Maamary, F., 2003. Effect of cement kiln dust (CKD) on mortar and concrete mixtures. Journal of Construction and Building Materials 17, 353 – 360.