## 6 Discussion of Results  
Several assumptions were made in the process of implementing the framework in the Weikendorf Bridge. Along with a discussion of the obtained results, this chapter provides clarification for some of these assumptions, as well as a study of their effect on the obtained results. One of the stated assumptions is that the highest measured carbonation depth should trigger corrosion first, which does not have to be the case. Due to this assumption, the parameters in Table 14 were chosen so that they match the highest measured value in point W4, thus influencing the subsequently determined \(t_{ini}\). However, when the mean of the measured values presented in Table 12 is observed, the duration of the initiation phase \(t_{ini}\) becomes significantly longer than the one obtained in Table 15. Hence, in order to understand the influence of duration of initiation phase, the range of mean values of \(t_{ini}\) = 20, 30...100 years, with the coefficient of variation \(c_{v}\) = 0.5, was analyzed. Figure 10 depicts the probabilities that the process will assume one of the condition states \(i\) for the subsequent period \(k\) = 50 years, taking into account the condition state CS1 at the age of 0 years.  
Other important implications assumed in the article are the corrosion rate \(v_{corr}\) and duration of propagation periods being based on recommendations given in [7]. These recommendations lead to the mean value of corrosion rate \(v_{corr}\) = 22 \(\upmu\)m/year being used in the analysis. However, according to [62], corrosion rates higher than 1 \(\upmu\)A/cm\({}^{2}\) (\(\approx\) 16 \(\upmu\)m/year) are seldom measured, while values between 0.1-1.0 \(\upmu\)A/cm\({}^{2}\) (\(\approx\) 1.6-16.0 \(\upmu\)m/year) are the most frequent. Therefore, the mean corrosion rate was altered in the range \(v_{corr}\) = 4, 8...16 \(\upmu\)m/year, with coefficient of variation \(c_{v}\) = 0.5, in order to understand the behavior of the process for lower corrosion rates. For such ranges of corrosion rates, the probabilities that the process will assume one of the condition states \(i\) for the subsequent period \(k\) = 50 years, taking into account the condition state CS1 at an age of 0 years, are depicted in Figure 11. As can be seen in Figure 11, the probabilities of collapse for the corrosion rate \(v_{corr}\) < 4 \(\upmu\)m/year are almost equal to zero for the first 50 years.  
The analysis of the duration of the collapse period was performed for the robustness class ROC3, which assumes a 25% cross-section loss, as presented in Tables 17 and 18. However, it should be noted that different collapse modes are possible in other bridge elements.  
It is important to mention that due to lack of data before 2005, it was assumed that the bridge entered in CS3 in 2005 and stayed in the same state until the last inspection in 2013, before it was repaired. Nonetheless, it is possible that the bridge was already in the state CS3 prior to inspection in 2005. For this reason, to account for the recorded (past and present) duration of the bridge being in a certain state, sojourn times of these states have to be adjusted according to records.  
Figure 10: Probability that the process will assume one of the condition states \(i\) at the age of 50 years, given for different durations of initiation phase \(t_{ini}\).  
When analyzing the obtained results presented in Figure 9, one has to bear in mind that these results show the condition forecast only for the case of carbonation-induced corrosion. However, the Weikendorf Bridge was affected with other deterioration processes, as well, such as chloride ingress. In fact, very often a structure is affected by multiple deterioration processes at once. Unfortunately, the combined effects of various deterioration processes have not yet been studied in detail. Hence, at the moment, to account for multiple deterioration processes, only possible solution is to summon the probabilities of reaching the same condition state caused by different processes.