Retail foot-traffic relief is coming to the downtown Santa Rosa construction zone, as concrete for key sidewalks linking shops around the Courthouse Square reunification project is being poured starting Thursday.

Crews from concrete contractor Conco pumped brown-tinted concrete into forms in front of the 50 Old Courthouse Square building. The project to reunify the square started in May after about 20 years of discussion. It was supposed to be finished in November before the holiday shopping period, but delays for redesigned electrical outlets and discovery of a buried heating-oil tank pushed the completion date into spring 2017.

The city’s closure of the walkway between Third and Fourth streets about 10 days before Christmas in preparation for the concrete work being done today made it tough for customers to get to retail merchants on Fourth Street.

“It will be great when it’s done,” said Kelley Rajala, majority owner of Made Local Marketplace across from the square. Rajala said she was upset when the city closed the walkway.

Pouring concrete for the new walkway along the east end of the square will take two days, according to a foreman on the job. The northeastern part of the walkway will be done Thursday and the rest poured Friday.

Fresh concrete can be walked on after about two days, he said, and it continues curing indefinitely. Most of its strength is attained in less than four weeks of curing.

New sidewalks in front of the Empire Building on the west end of the rejoined square will follow, requiring closure of that walkway.

A sign for Booze Barrel indicated that the restaurant will open soon at 614 Fourth, on the corner of the square. Flavor bistro, located along the walkway closed since Dec. 16, closed in November after a dozen years in business.

Conco has offices in San Francisco.