The pilot reported he had been working at an off-airport site installing concrete columns and was departing from the site in the tailwheel-equipped accident airplane. During takeoff from the field, he turned to avoid trees at the end of the field and impacted a concrete column. Examination of the wreckage by a Federal Aviation Administration inspector revealed the right wing and fuselage were substantially damaged. The pilot reported there were no preimpact mechanical malfunctions or anomalies that would have precluded normal operation of the airplane. He stated he had experience taking off on grass, but he had not left enough room to gain sufficient altitude for obstacle clearance.