Confined Lightweight Aggregate Concrete using Soft Attention Mechanism-Bidirectional Gated Recurrent Unit for Stress-strain Relationship

The construction industry might play a significant role in reducing waste by utilising plastic waste in different applications, like concrete, as it significantly contributes to environmental pollution. In this work, a strain model and concrete stress under compression for constrained specimens in concrete is developed, and coarse material is replaced by polypropylene plastic. The effects of steel confinement, compressive performance, and stress and strain characteristics were examined in a variety of short-column specimens. The addition of steel confinement improved the section's ductility and compressive strength. By parametrically identifying a stress-strain model developed for normal concrete, novel parameter values for confinement k_1, suitable for sections of lightweight concrete that are square and cylindrical, were produced based on experimental results. When compared to stress-strain modelled by the adjusted coefficients, the experimental cylinder and square column specimen's stress-strain diagrams for lightweight concrete show a good agreement. The data are analyzed using SAM-BiGRU which achieves a less Root Mean Square Error (RMSE) of 0.4536 compared to existing methods like Cross-Attention Mechanism-BiGRU (CAM-BiGRU).