1. Features and application of concrete poles There are many advantages of pre-stressed concrete poles, so they are developing rapidly. Compared with common concrete poles, their strong points are as follows: A. Saving a great deal of steel, about 30~70% (employing cold drawn steel wire can save 30%~60%; employing high stress steel wire can save 40%~69%); B. Crack resistance increased 3~5 times; C. Rigidity increased 1~3 times; D. Reducing the cost (using cold drawn steel wire can reduce 25%~40%; using high stress steel wire can reduce 12%~21%); E. Good durability, can delay the existence and expansion of cracks; F. Protect the environment on which human beings depend on for existence, and reduce the deforestation. 2. A summary of pre-stressed poles development trend Pre-pressed concrete poles are produced strictly according to two standards namely gb396-94 circular reinforced concrete pole and gb4623-94 circular pre-stressed concrete pole of p.R.C., which guided enterprises and construction units for manufacture and