I went back to take some photos of a previous job we done beginning of February for Sarah Evans from Hassell Architect.
She wanted to achieved a concrete look but without to many imperfections and been practical and easy to maintain for a kitchen splash back.
We use a two coats system lime render with different aggregate such as quartz silica and finest marble dust for last coat, this a old technic of application I learn back in France, the result is quite amazing if you look to replicate concrete slab or a polished concrete wall, this is the finish you want.
for the easy maintenance we seal the wall with one of our water based low-VOC Polyhurthane sealer
Lime plaster and render are limit less in regard of creativity