Abstract
As concrete buildings age the significance of them becomes more important as they are seen as historic icons and in some countries are protected by local laws. This puts a large demand on their service life requirements as they are expected to last indefinitely. The lifetime of these buildings is most commonly dictated by corrosion of the embedded reinforcing steel cause by carbonation. Challenges with carbonation comes down to dealing with the length of time before corrosion will be initiated and then how long it takes in the propagation phase before damage to the concrete occurs.
The paper will look at various carbonation models used by practitioners which provide a level of prediction to future degradation and evaluate how effective these are in the real world. An emphasis will be on environmental conditions and how this impacts performance of the building. These environmental indexes are required on most structures if any level of accuracy is required. In addition to establishing parameters required by service life models, inspection techniques will be reviewed for their applicability on understanding underlying corrosion conditions.
Understanding the impact of material degradation, rates of deterioration, and condition state changes are critical in making sound repair choices for historic concrete structures. Forecasting remaining service life and planning for durability is critical, particularly when the subject structure is an irreplaceable landmark. By monitoring the long-term performance of a structure, a corrosion and degradation rates can be established. Multiple parameters on the subject reinforced concrete structure are tested and monitored. The data is then utilized in durability and service life models to understand where the structure is in regard to critical performance thresholds and when failures may occur. This approach, when applied to historic structures, can help provide an understanding of ‘anticipated remaining service life’ and to assist in developing a proactive repair.
