Correction: Guo et al. Preparation and Performance Study of Sand-Containing Hollow Concrete with Alkali-Activated Recycled Concrete Powder Based on Target Porosity. Coatings 2026, 16, 313

In the original publication [1], there was a mistake in Figures 2, 5 and 15.

In Figure 2, the names of the substances in the original image were changed from their original names to chemical formulas, making it easier for readers to understand the composition of the substances and making the image clearer. The corrected Figure 2 appears below.

In the case of Figure 5, in Section 2.3.1 of the RCP pre-treatment, the RCP grinding time was set to 0, 10 min, 20 min, and 30 min. However, due to the numerous experiments conducted, in the other experiments, the RCP activity index was tested at 20 min, 40 min, and 60 min. During the plotting, the incorrect data was used, so it needs to be modified; but, the analysis part does not affect it and remains correct. Therefore, this figure has been modified. The corrected Figure 5 appears below.

In Figure 15b, the magnification annotation is incorrect; it should be 500 nm. The annotation has been corrected, and the length of the scale bar has been properly calibrated. The corrected Figure 15 appears below.

The authors state that the scientific conclusions are unaffected. This correction was approved by the Academic Editor. The original publication has also been updated.