Machine Learning Prediction Models to Evaluate the Strength of Recycled Aggregate Concrete

Xiongzhou Yuan; Yuze Tian; Waqas Ahmad; Ayaz Ahmad; Kseniia Iurevna Usanova; Abdeliazim Mustafa Mohamed; Rana Khallaf

doi:10.3390/ma15082823

Machine Learning Prediction Models to Evaluate the Strength of Recycled Aggregate Concrete

Materials (Basel). 2022 Apr 12;15(8):2823. doi: 10.3390/ma15082823.

Authors

Xiongzhou Yuan¹, Yuze Tian², Waqas Ahmad³, Ayaz Ahmad^{3

4}, Kseniia Iurevna Usanova⁵, Abdeliazim Mustafa Mohamed^{6

7}, Rana Khallaf⁸

Affiliations

¹ School of Traffic and Environment, Shenzhen Institute of Information Technology, Shenzhen 518172, China.
² School of Civil Engineering, University of Science and Technology Liaoning, Anshan 114051, China.
³ Department of Civil Engineering, COMSATS University Islamabad, Abbottabad 22060, Pakistan.
⁴ MaREI Centre, Ryan Institute, School of Engineering, College of Science and Engineering, National University of Ireland, H91 TK33 Galway, Ireland.
⁵ Peter the Great St. Petersburg Polytechnic University, 195291 St. Petersburg, Russia.
⁶ Department of Civil Engineering, College of Engineering in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia.
⁷ Building & Construction Technology Department, Bayan College of Science and Technology, Khartoum 11115, Sudan.
⁸ Structural Engineering and Construction Management, Faculty of Engineering and Technology, Future University in Egypt, New Cairo 11845, Egypt.

Abstract

Compressive and flexural strength are the crucial properties of a material. The strength of recycled aggregate concrete (RAC) is comparatively lower than that of natural aggregate concrete. Several factors, including the recycled aggregate replacement ratio, parent concrete strength, water-cement ratio, water absorption, density of the recycled aggregate, etc., affect the RAC's strength. Several studies have been performed to study the impact of these factors individually. However, it is challenging to examine their combined impact on the strength of RAC through experimental investigations. Experimental studies involve casting, curing, and testing samples, for which substantial effort, price, and time are needed. For rapid and cost-effective research, it is critical to apply new methods to the stated purpose. In this research, the compressive and flexural strengths of RAC were predicted using ensemble machine learning methods, including gradient boosting and random forest. Twelve input factors were used in the dataset, and their influence on the strength of RAC was analyzed. The models were validated and compared using correlation coefficients (R²), variance between predicted and experimental results, statistical tests, and k-fold analysis. The random forest approach outperformed gradient boosting in anticipating the strength of RAC, with an R² of 0.91 and 0.86 for compressive and flexural strength, respectively. The models' decreased error values, such as mean absolute error (MAE) and root-mean-square error (RMSE), confirmed the higher precision of the random forest models. The MAE values for the random forest models were 4.19 MPa and 0.56 MPa, whereas the MAE values for the gradient boosting models were 4.78 MPa and 0.64 MPa, for compressive and flexural strengths, respectively. Machine learning technologies will benefit the construction sector by facilitating the evaluation of material properties in a quick and cost-effective manner.

Keywords: compressive strength; flexural strength; gradient boosting; random forest; recycled aggregate concrete; sustainable aggregate.

Grants and funding

No. 075-15-2020-934/Ministry of Science and Higher Education of the Russian Federation