*Article* **Application of Soft-Computing Methods to Evaluate the Compressive Strength of Self-Compacting Concrete**

**Muhammad Nasir Amin 1,\*, Mohammed Najeeb Al-Hashem 1, Ayaz Ahmad 2, Kaffayatullah Khan 1, Waqas Ahmad 3, Muhammad Ghulam Qadir 4, Muhammad Imran <sup>5</sup> and Qasem M. S. Al-Ahmad <sup>1</sup>**


**Abstract:** This research examined machine learning (ML) techniques for predicting the compressive strength (CS) of self-compacting concrete (SCC). Multilayer perceptron (MLP), bagging regressor (BR), and support vector machine (SVM) were utilized for analysis. A total of 169 data points were retrieved from the various published articles. The data set was based on 11 input parameters, such as cement, limestone, fly ash, ground granulated blast-furnace slag, silica fume, rice husk ash, coarse aggregate, fine aggregate, superplasticizers, water, viscosity modifying admixtures, and one output with compressive strength of SCC. In terms of properly predicting the CS of SCC, the BR technique outperformed both the SVM and MLP models, as determined by the research results. In contrast to SVM and MLP, the coefficient of determination (R2) for the BR model was 0.95, whereas for SVM and MLP, the R2 was 0.90 and 0.86, respectively. In addition, a k-fold cross-validation approach was adopted to check the accuracy of the employed models. The statistical measures mean absolute percent error, mean absolute error, and root mean square error ensure the validity of the model. Using sensitivity analysis, the influence of input factors on the intended CS of SCC was also explored. This analysis reveals that the highest contributing parameter towards the CS of SCC was cement with 16.2%, while rice husk ash contributed the least with 4.25% among all the input variables.

**Keywords:** concrete; self-compacting concrete; compressive strength; prediction models; machine learning
