[TowerTalk] Extending a concrete base?

[Paul Kelley N1BUG]

Here's another (maybe stupid) question...

I have a 25G tower with the bottom section partially embedded in 
concrete. Problem is the concrete was poured with the top only about 
an inch above ground. The base never moves but the surrounding earth 
frost heaves up slightly in winter. Spring snow melt and rain then 
deposits dirt and debris on top of the concrete where it then 
surrounds the tower legs. The tower is on sloped ground which 
promotes this action. I am tired of cleaning the dirt and debris off 
it every year and wonder what I can do to eliminate this situation.

If I clean (wire brush?) the top of the existing concrete, build a 
wood form around it and simply pour another few inches of concrete 
on top, will I be helping or making matters worse? I am wondering if 
the new concrete will adhere to the old stuff adequately, or if 
water may tend to get in between old and new layers (where it would 
no doubt freeze and cause bigger problems).

I have worked with concrete quit a bit, but have never poured new on 
top of old. Any advice would be appreciated.

Thanks & 73,

Paul N1BUG