# Seismic Resilience of CRC- vs. RC-Reinforced Buildings: A Long-Term Evaluation
## 2 Methodology  
In this section, we introduce a novel methodology for assessing the earthquake resistance of the building over an extended period. Our approach is divided into two primary stages, focusing on structures reinforced with conventional steel and those reinforced with CFRP. The methodology aims to capture the changes in material properties due to corrosion and other factors affecting both types of structures. The resistance assessment benefits from the DEM, which quantifies the structure's resistance ratio through the comparison of dissipation energies across different testing periods. This process generates a series of ratios that, over time, are used to construct a predictive curve for seismic resistance. The second stage replicates the first but examines structures reinforced with CFRP to assess the impact of non-corrosive reinforcement on seismic resistance under identical geophysical conditions. This stage follows the same procedural steps as outlined for RC structures, with adaptations to account for the different mechanical properties of CFRP, as depicted in Figure 1. This methodology is grounded in established scientific principles and validated modeling techniques that comprehensively analyze structures reinforced with conventional RC and CFRP.  
**Objective:** The primary goal of this work is to evaluate how corrosion affects the mechanical properties of both RC and CRC structures.  
This objective is achieved by adopting predictive models/equations that can replicate the long-term changes in these properties due to corrosion. The methodology includes the following steps:  
1. We begin by generating detailed geometric models of the structural frames.
2. Identification of the parameters likely to deteriorate due to corrosion, including the steel reinforcement area, the residual cross-section area, the strength and elastic modulus of both reinforced and plain concretes, as well as the residual strength of the CFRP. These parameters are critical as they directly impact the structural integrity and load-bearing capacity of RC and CRC structures. The identified parameters are then used as input for the models so that the simulations are performed in discreet periods throughout the structure's expected lifetime.
3. Simulation of both structures utilizing the POA technique with SAP2000 ver. 17 [28] and Response2000 ver. 1.9.6. beta [29] models to evaluate the response to lateral seismic loads. These simulations utilize the parameters defined in the first step. The analysis yields load-displacement curves for the following step.
4. The simulations generate load-displacement curves, which are then used to calculate dissipation energy ratios. This step is pivotal as it allows us to determine the energy dissipation at any selected time, providing insights into the resilience of the structure and its effectiveness in dissipating seismic energy.  
Figure 1: Methodology framework.  
5. The energy values obtained from integrating the load-displacement curves for each specified age interval (e.g., t = 20,..., t = N) are compared with the structure's non-corrosive state at t = 0. The resulting ratio, the RCF, quantitatively measures the structure's ability to dissipate energy relative to its original condition. This factor is crucial for understanding how corrosion impacts structural resilience and durability, highlighting the long-term effects of environmental and material degradation on structural integrity.
6. The main innovation of this methodology lies in its potential to enhance the motivation for using CFRP as a reinforcement material in concrete structures. This is due to CFRP's superior performance in terms of seismic resistance, particularly over long periods, compared to conventional steel-reinforced concrete.