## 4 Conclusions  
The experimental objectives of this study are to investigate the relationship between properties and pore structures in alkali-activated shield machine much solidified bodies under carbonation curing at varying temperature-humidity conditions, the connection between pore solution alkalinity and temperature-humidity conditions, and the effects of temperature and humidity on carbonation and hydration products. Additionally, the mechanistic roles of temperature and humidity were summarized and analyzed:  
1. The proportion of harmful pores (>1000 nm) exhibited a highly significant negative correlation with compressive strength, while pores <1000 nm showed a weaker positive correlation. Reducing harmful pore content constitutes the key to improving mechanical performance in alkali-activated slag shield machine much solidified bodies;
2. The 28-day compressive strength demonstrated a distinct initial increase followed by a decrease across the tested temperature-humidity gradient range. The maximum strength occurred at 20 \({}^{\circ}\)C/70% RH, showing a 36.1% enhancement when compared with standard curing, fully confirming that controlled temperature-humidity conditions during carbonation curing can effectively improve mechanical properties of alkali-activated slag shield machine much solidified bodies;
3. The temperature-humidity conditions during carbonation curing showed negligible but measurable effects on the alkaline environment of pore solutions. These effects primarily manifested through humidity-controlled pore solution dilution and ion migration processes, as well as temperature-regulated Ca\({}^{2+}\) dissolution and pore solution evaporation;
4. The carbon absorption rates gradually increased with a rising temperature and decreasing humidity, indicating intensified carbonation reactions. The crystalline carbonation product was identified as calcite, while the hydration product remained the C-A-S-H gel phase. Under high-temperature/low-humidity conditions, an accelerated decomposition of C-A-S-H gel through carbonation promoted continuous growth and a coarsening of calcite crystals, leading to non-uniform deposition. This ineffective filling of harmful pores ultimately degraded mechanical performance.  
K.W.: Writing--original draft, Visualization, Software, Investigation, Data curation; S.H.: Writing--Investigation, review and editing: Y.L.: Writing--review and editing, Resources, Supervision, Funding acquisition; Z.X.: Conceptualization; J.Q.: Investigation; B.Y.: Writing--review and editing, Resources, Supervision, Funding acquisition. All authors have read and agreed to the published version of the manuscript.  
This work was supported by the Natural Science Foundation of Hunan Province, China (Grant No. 2024J9079) and the National Key Research and Development Program of China (Grant No. 2022 YFC3803402).  
Not applicable.  
The original contributions presented in the study are included in the article; further inquiries can be directed to the corresponding author.  
Authors [PERSON] and [PERSON] were employed by the company China Construction Fifth Engineering Bureau Co., Ltd. (Changsha, China). 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.