## 5 Conclusions  
A long-term measurement experiment was conducted for thin-walled concrete temperature as well as environmental factors, and the measured data were analyzed using various methods; the detailed conclusions were as follows:  
1. For green and environmentally friendly resource consumption in the temperature measurement experiment, a concrete block specimen with a layer of thermal insulation material on the lateral surface was used to simulate thin-walled concrete. Furthermore, this method was verified by a result showing that the vertical temperature difference was the dominant difference in the whole temperature field.
2. Seasonally, the Tm was highest in summer and lowest in winter, while the \(T_{\rm m}\) in spring had the most drastic fluctuations. Two extreme gradient temperature patterns, \(T_{\rm g}^{+}\) and \(T_{\rm g}^{-}\), occurred in summer and winter, respectively. The \(T_{\rm g}^{-}\) in winter was \(-0.26\) times the \(T_{\rm g}^{+}\) in summer, which is close to the AASHTO LRDF-recommended value. In addition, the \(T_{\rm g}^{+}\) and \(T_{\rm g}^{-}\) in all seasons could be expressed by an exponential function with parameters composed of the corresponding \(T_{\rm gb}\) and \(T_{\rm gt}\), as well as \(a=11.5\).
3. Random forest regression was applied to analyze the specimen's sensitivity to environmental factors, which found that wind speed was negligible for the thin-walled concrete temperature field. Moreover, air temperature controlled the concrete Tm, while solar radiation was the dominant factor for \(T_{\rm gb}\) and \(T_{\rm gt}\).
4. Regarding the mean temperature, \(T_{\rm m}^{\rm min}\), \(T_{\rm m}^{\rm avg}\), and \(T_{\rm m}^{\rm max}\) were all linearly and positively correlated with the average air temperature and the correlation ratios (\({}^{\circ}\)C/\({}^{\circ}\)C) were, respectively, 0.97, 1.02, and 1.08, with a difference of less than 11.3%, indicating that fluctuations in the mean temperature within a day were small.
5. The patterns of gradient temperature changes were different for different elevations. For the bottom shadowed surface, \(T_{\rm gb}^{\rm min}\) and \(T_{\rm gb}^{\rm avg}\) were both linearly and negatively correlated with the average solar radiation with correlation ratios (\({}^{\circ}\)C/kW) of \(-11.4\) and \(-5.37\), respectively. At the top radiated surface, both \(T_{\rm gt}^{\rm max}\) and \(T_{\rm gt}^{\rm avg}\) had a positive linear correlation with the average solar radiation, and the correlation ratios (\({}^{\circ}\)C/kW) were 35.0 and 9.6, respectively.  
Conceptualization, W.Y. and H.X.; methodology, H.X. and M.P.; software--algorithm development, W.Y. and M.X.; validation, H.X. and L.Z.; formal analysis, W.Y. and J.P.; investigation, W.Y. and J.P.; resources, H.X. and M.P.; data curation, L.Z. and W.Y.; writing--original draft preparation, W.Y.; writing--review and editing, H.X. and M.P.; visualization, M.X. and L.Z.; supervision, H.X. All authors have read and agreed to the published version of the manuscript. This research received no external funding. This research received no external funding. Not applicable. Informed Consent Statement: Informed consent was obtained from all subjects involved in the study. The data that support the findings of this study are available from the first author, [PERSON], upon reasonable request. The authors declare no conflict of interest. Author [PERSON] and [PERSON] were employed by the company Power China Chengdu Engineering Corporation Limited. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.