Kambiz Daneshvar

One of the practical ways to overcome the adverse environmental effects of plastic bottle waste is to implement bottles into concrete, one of the most widely used materials in the construction industry. Plastic bottles are mainly made of polyethylene terephthalate (PET) and can be used as a fiber to reinforce concrete. In recent years, PET fiber-reinforced concrete (PFRC) has attracted researcher attention, and several experimental studies have been conducted. This paper aims to present the benefits of using PET fiber as a reinforcing element in concrete using a machine learning approach. By considering the effect of PET fibers in concrete, engineers and stakeholders may be encouraged to further use these recycled materials. The proposed network was successfully able to capture the response of PFRC with high accuracy (mean squared error (MSE) of 7.11 MPa and R coefficient of 98%). The results of the proposed network show that the amount of PET fiber usage in concrete has a significant effect on the compressive strength of PFRC. Moreover, the PFRC’s response considering the variation of mechanical and geometrical properties of PET fiber mainly depends on the fiber’s shape. The most effective shapes of PET fiber are shapes with deformation, followed by embossed and irregular shapes.

Shear walls are lateral load–resisting systems that provide lateral strength and stiffness in order to reduce the horizontal sway of a building. Over recent years, composite shear walls with steel-encased profiles (CSRCWs) have attracted increasing attention. This paper aims to numerically investigate the impact of axial loads on the seismic behavior of shear walls. Numerical modeling was carried out via OpenSees. Five composite shear walls with different shapes of steel-encased profile and one typical reinforced concrete (RC) shear wall subjected to lateral cyclic displacements and different levels of axial load in the range of 10%–40% of axial load capacity were investigated. The findings revealed that increasing the axial compressive load ratio has a negative effect on the seismic behavior of shear walls. In addition, the results showed that shear walls with steel-encased profiles have more flexibility, stiffness, and energy dissipation compared with typical RC shear walls under the same axial load.