## 2 Experimental
### Pilot Programme  
(1) Specim Preparation  
According to the specification requirements for specimen preparation, the specimens are to be cut evenly along the width of the membrane, with the long edge of the specimen aligned with the longitudinal direction of the web and at least 150 mm from the edge [27]. The cut specimens are classified into three types: A, B, and C. Type A specimens measure 25 mm \(\times\) 150 mm and are used for low-temperature flexibility tests and Fourier infrared \begin{table}
\begin{tabular}{c c} \hline \hline
**Property** & **Measured Values** \\ \hline Thicknesses (mm) & 3.0 \\ Tensile strength (N/50 mm) & 620/500 \\ Elongation at maximum tension (\%) & 39 \\ Soluble matter content (g/m\({}^{2}\)) & 2208 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Characteristics of self-adhesive asphalt waterproofing membranes. spectroscopy after thermo-oxidative and freeze-thaw cyclic aging. Type B specimens measure 50 mm \(\times\) 300 mm and are used for tensile testing after thermo-oxidative and freeze-thaw cyclic aging. Type C specimens measure 50 mm \(\times\) 200 mm and are used for peeling tests following thermo-oxidative and freeze-thaw cyclic aging. 2. Aging process This paper examines the changes in the properties of self-adhesive membranes under two distinct aging conditions: thermo-oxidative aging and freeze-thaw cycle aging. The test uses a thin film oven (TFO) to simulate the high temperatures encountered by roofs and facades during summer, with aging duration as the test variable. Based on measurements of external wall temperatures during peak summer conditions [28], the test temperature was set at 80 \({}^{\circ}\)C, and the aging durations were 2, 5, 7, 14, and 28 days. After completing the thermo-oxidative aging test, the specimens were placed in a constant temperature and humidity incubator for 24 h before undergoing the freeze-thaw cycle aging test. The freeze-thaw cycle aging was conducted in a freeze-thaw cycle tester (FTCT), where the test conditions involved freezing at -20 \({}^{\circ}\)C for 12 h, followed by stabilization at a constant temperature of 23 \({}^{\circ}\)C (\(\pm\)2) for 12 h. The freeze-thaw cycle duration for each specimen corresponded to its thermo-oxidative aging time. Specimens that have undergone both thermo-oxidative aging and freeze-thaw cycles are to be subjected to low-temperature flexibility tests, Fourier infrared spectroscopy (FTIR), and mechanical property tests. The flowchart of the test is shown in Figure 2.
3. Test Methods The tensile performance and seam peeling performance tests were conducted in accordance with the \"Test Methods for Building Sheets for Waterproofing\" (GB/T 328.8-2007 and GB/T 328.20-2007) [29; 30]. An electronic universal testing machine was used as the testing instrument. The dimensions of the peeling specimen were 200 mm \(\times\) 50 mm, with a seam width of 100 mm. The fixture spacing was set at 100 mm, and the fixture movement during the test was maintained at a constant rate of 100 mm/min. Fourier Transform Infrared Spectroscopy (FTIR) tests were performed using a Bruker B420 spectrometer (Bruker Corporation, Billerica, MA, USA) equipped with an attenuated total reflection (ATR) diamond accessory. The wavenumber range for the FTIR test was 4000 cm\({}^{-1}\) to 340 cm\({}^{-1}\), with 16 scans conducted for each measurement. The chemical properties of waterproofing membranes can be further analyzed by calculating the functional group index based on the following formula derived from the results of the infrared test spectra: Carbonyl functional group index: \[I_{C=O}=\frac{\text{Carboniferous peak }\left(\text{Centred at 1700 cm}^{-1}\right)\text{area}}{\text{ Peak area between 600 and 2000 cm}^{-1}}\] (1)  
Figure 2: A flowchart of the experimental study sequence.