A concerned passerby decided to call police when they saw a man angrily smashing a concrete driveway with a sledgehammer last month.
Horace Hughes got into an argument on January 13, the Whanganui District Court heard yesterday.
He grabbed a tomahawk, went outside, and began smashing the concrete, police prosecutor Sergeant Drew Morrison said.
The tomahawk then broke, so Hughes found a sledgehammer and continued smashing the driveway.
Mr Morrison said a passerby called police.
When spoken to by police, Hughes said he was trying to intimidate the person he argued with.
He pleaded guilty yesterday to possessing an offensive weapon. While the summary of facts said Hughes had argued with his flatmate, defence lawyer Anna Brosnahan said the argument was actually with family.
"He had family and friends at his address," Ms Brosnahan said.
"There had been some ongoing family issues in relation to his daughter. He felt he had been left out of those discussions and got frustrated."
She said Hughes was last before the court in 2001.
Judge David Cameron ordered Hughes to come up for sentence if called upon within six months, and ordered the destruction of the tomahawk and sledgehammer.