• Dry curing ( 90 % reduced shrinkage by nearly 15-fold compared to dry conditions. The 70RHA mixture demonstrated the highest shrinkage under low RH, associated with its refined micropore structure and elevated internal surface area. Nitrogen adsorption-desorption analysis revealed that low RH hindered pore refinement, while wet curing promoted gel densification, increasing the fraction of pores below 5 nm and improving compressive strength. At intermediate RH, mesopore volume increased after 28 days, consistent with microstructural changes associated with moisture exchange processes. This work provides a combined analysis of humidity-dependent shrinkage mechanisms and pore structure evolution in hybrid alkaline systems incorporating industrial and agricultural residues. The main contribution lies in identifying two distinct shrinkage regimes governed by pore-scale mechanisms under different RH conditions, offering practical guidance for curing optimisation and dimensional stability control in sustainable cementitious materials.
Moraes et al. (Sun,) studied this question.