Please suggest me concrete cracking agents

Which concrete cracking agents are useful to break the concrete easier, and please suggest me good products that are not harmfull for steel reinforcement.
 

vjmahadik When you use the term "agents" do you mean to say "equipment?" What type of work are you performing and on what type(s) of structural elements are you working on?

In that concrete cracking agents means concrete products that are create cracks in concrete. we are using concrete breakers to breaking the M60 grade of column due to honeycomb, but breaking of that column is taking more time and that structure are very hard to breaking. so we find some concrete cracker agents (without effects any steel reinforcement structure) that are generate cracks in concrete for easier breaking of that structure in less duration.