The phrase "first concrete" means the initial or earliest example of something specific or tangible. It refers to the very first time something real or material is seen or experienced. Full definition
These training sessions are the school district's first concrete steps toward replacing its age - old teacher evaluation system, which is widely regarded as a failure. (articles.latimes.com)
Their typical build time from first concrete to commercial operation is less than five years. (johnquiggin.com)
Translated from Spanish, it said, «First concrete action should be take cash out of Banrural and bankrupt the bank of the corrupt.» (legalblogwatch.typepad.com)