*Article* **Predicting the Rheological Properties of Super-Plasticized Concrete Using Modeling Techniques**

**Muhammad Nasir Amin 1,\*, Ayaz Ahmad 2, Kaffayatullah Khan 1, Waqas Ahmad 3, Saqib Ehsan <sup>4</sup> and Anas Abdulalim Alabdullah <sup>1</sup>**


**Abstract:** Interface yield stress (YS) and plastic viscosity (PV) have a significant impact on the pumpability of concrete mixes. This study is based on the application of predictive machine learning (PML) techniques to forecast the rheological properties of fresh concrete. The artificial neural network (NN) and random forest (R-F) PML approaches were introduced to anticipate the PV and YS of concrete. In comparison, the R-F model outperforms the NN model by giving the coefficient of determination (R2) values equal to 0.92 and 0.96 for PV and YS, respectively. In contrast, the model's legitimacy was also verified by applying statistical checks and a k-fold cross validation approach. The mean absolute error, mean square error, and root mean square error values for R-F models by investigating the YS were noted as 30.36 Pa, 1141.76 Pa, and 33.79 Pa, respectively. Similarly, for the PV, these values were noted as 3.52 Pa·s, 16.48 Pa·s, and 4.06 Pa·s, respectively. However, by comparing these values with the NN's model, they were found to be higher, which also gives confirmation of R-F's high precision in terms of predicting the outcomes. A validation approach known as k-fold cross validation was also introduced to authenticate the precision of employed models. Moreover, the influence of the input parameters was also investigated with regard to predictions of PV and YS. The proposed study will be beneficial for the researchers and construction industries in terms of saving time, effort, and cost of a project.

**Keywords:** concrete; plastic viscosity; yield stress; modeling; machine learning
