In Lawrence, CSI doesn’t just refer to the crime scene investigators who have become the rage on television shows these days.

It also could very well refer to a concrete science inspector, which also is becoming more of the rage at City Hall. City officials several years ago realized they needed to take more steps to ensure that the city’s curbs and gutters didn’t crumble prematurely.

“It has been a point of emphasis for me,” City Manager Mike Wildgen said of efforts to improve the durability of the often-times expensive curbs and gutters.

The result is that now it is common for a city employee to be on job sites poking, prodding and shaping concrete to make sure that it is up to snuff. The city now has five construction inspectors in the public work’s department, up from two just three years ago.

“Basically all they were getting done before is putting out fires,” said Ed Ogle, the city’s engineering supervisor. “Now we’re really able to do some testing.”

The inspectors have been busy lately. Crews hired by the city have been working this summer on replacing curbs and gutters in approximately one dozen areas of town.

Ogle said some of the curbs and gutters have been replaced after less than 15 years in service, which is about half as long as engineers would expect a curb to survive.

Ogle said that, with the help of the inspectors, the city has changed its standards for concrete. Ogle said the city is putting more coarse aggregates – like granite – into the cement mix and less of the area’s native limestone, which is a softer rock. Changes in the type of sand also have been made.

As for the inspections, Ogle said city employees now check the temperature of the concrete before it is poured, check for a proper amount of air in the mix – which allows the concrete to expand and contract during freezing – and do tests to determine how well the concrete holds its shape before it sets.

Wildgen said he thought the efforts were helping, though he said he still fields questions about curbs that have deteriorated after just two or three years. He said those cases are few and far between. He said some curbs installed in the Foxfire neighborhood in West Lawrence were a disappointment and failed far too soon.

Ogle, though, said many times city residents who complain about crumbling curbs are mistaken about how long it has been since an area received new curbs. For example, a portion of Bob Billings Parkway east of Kasold Drive is slated for new curbs even though the street had a major repaving in 2002. But curbs weren’t part of that project.

Wildgen said the city would take action against contractors who provided faulty workmanship, but said that he didn’t believe that had been the problem with crumbling curbs.

“That hasn’t been the situation really,” Wildgen said.

Ogle said the city’s policy of salting and sanding each street during snowstorms and on-street parking added to the deterioration of curbs.