## 6 Integrated Large-Scale Conservation Projects  
### During Decay Diagnosis: The Case of Pythian Apollo Temple in Rhodes  
In the case of the Temple of Pythian Apollo of Rhodes, IRT was used as a part of a large-scale restoration project. The IRT was initially used at the diagnostic campaign, before the compilation of the conservation interventions study, which will be accomplished by Dodecanese Ephrate of Antiquities. The Temple of Pythian Apollo of Rhodes is located in the southern area of the Acropolis of the island and dates from the 3 rd century BC. It is a peripteral Doric order temple, with dimensions of 20.05 m in width and 37.37 m in length, which consists of 6 columns on the small side and 11 on the long side [34]. The temple is orientated from east to west and is entrenched in an artificially shaped rock at its centre [35]. During the first Italian excavations (1912-1936), pieces from the ruins of the temple were revealed. The complete anastylosis of four columns and part of the entablature on the eastern corner of the temple began in 1938 (Figure 26), although the experts, headed by the archaeologist [PERSON] [35], were not sure about the original architectural morphology of the temple. The authentic stone material that was found (a fossil ferrous bioclacarenite stone) was limited. Thus, the restoration works were performed using either an artificial stone made of concrete, or bioclacarenite restoration stones. Concrete and cement products were also used in order to fill the drums (Figure 27). The stone core of the shafts was removed, and reinforced concrete was injected into it. Moreover, cement mortars, metal joints and lattices have been used for the mechanical support and stabilization of the stones. In recent years, scaffolding was put in place by the Greek archaeological service (Figure 28). In this case, IRT was used in the diagnosis of the monument's state of conservation. Firstly, IRT was applied in order to investigate the different materials, especially to identify the authentic stone pieces and the different types of decay. Moreover, it was used to detect moist areas, since the temple is located very close to the sea and in contact with possible underground water sources. Other non-destructive techniques were also applied in situ with portable devices like a digital microscope, Schmidt hammer test, thermohygrometer and colorimeter. Moreover, after sampling, analytical techniques such as optical microscopy, X-Ray Diffraction analysis (XRD), Differential Thermal analysis (DTA)/Thermogravinetry Analysis (TG), Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-Ray Spectrosopy (EDAX) and total soluble salts measurements were used. Metric results were concluded in the GIS program [36], from each implemented technique of the diagnostic study [37]. Finally, finite element analysis (FEM) was performed and, by coupling all the results, final conclusions were derived [37]. During the IRT investigation, multiple peripheral thermal scanning measurements of the columns and the stairs of the monument were performed every hour of every day. Also, a portable thermo-hygrometer (Flir, model MR77) was used in order to calibrate the infrared camera temperature indications and to evaluate the variations of materials temperature and moisture content with height. In this way, thermal maps of the columns were created. Table 3 shows the air temperature and relative humidity during image captions. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Thermogram Figure** & **Time** & **Date** & **Air T** & **Air RH \%** \\ \hline
29 & 12:00 & 13 November 2016 & 18.3 & 59.7 \\
30 & 14:00 & 13 November 2016 & 19.1 & 59.4 \\
31 & 11:00 & 13 November 2016 & 18.0 & 61.2 \\
32 & 13:00 & 13 November 2016 & 18.7 & 60.7 \\
34 & 10:00 & 13 November 2016 & 17.5 & 62.7 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Climatic conditions during IRT captures. Figure 28: The Temple of [PERSON] of Rhodes Today (2017).