IF it's confirmed that it will hit Earth, blowing it up is a viable solution.No it wouldn't. The shower of smaller fragments would have considerably greater surface area, allowing for both more complete burnup in the atmosphere (less mass reaches the ground) and lower impact velocity for those fragments that DO reach the ground. It would be slightly more dangerous to orbiting spacecraft and satellites, but considerably less so for anyone on the ground.Besides that, turning it into smaller rocks blasting in every direction would make it more dangerous. Good job.
You're turning an asteroid that definitely won't hit Earth into a gazillion of smaller ones that will hit Earth.
If it's not going to hit Earth, blowing it up is neither a hazard nor a solution but is just a waste of time; the debris field will not scatter far enough or fast enough to hit Earth anyway and would only be a hazard to spacecraft and probes in high orbit.