You could use textured paints on inside and stone accents for the outer box.

Our structural team working on the new project of steel detailing. take a look at our work. Your feedback is welcome.

Hello mahesh, For an exposed MS Structures we usually suggest a first coating of zinc chromate paint which makes the steel rustfree though regular maintenance is needed ..on top of this you will have to paint with your desired colour paint either matte or glossy as per your preference. If that s already painted and the rusted, completely remove and scrap of the paint before you apply zinc chromate paint. Hope our answer helped your query do contact us for professional help

Following are the reasons for the honeycomb in the pictures shared by you: 1. Bad grade quality concrete mix that is higher portion of coarse aggregates with respect to fine aggregates and cement. 2. Also, it looks like the water cement ratio is less than 0.3. 3. Vibrators are not effectively used for efficient compaction.