12th Avenue runs through the heart of the residential district of Hiawatha and connects a popular shopping area to the community’s medical park. The surface of 12th Avenue was experiencing severe surface cracking and deterioration, with deep fissures posing a threat to vehicular and pedestrian safety along the corridor. Occasional season fill and patch had sufficed, but the City recognized that this popular thoroughfare required more than just a quick fix.

MSA had been providing Hiawatha with municipal engineering services for over a decade, and was selected to rehabilitate the avenue with a full depth repair and upgrades to pedestrian and multi-modal safety with new ADA-compliant sidewalk and curb ramps.

Residents throughout the neighborhood voiced concerns that vehicles would drive at faster speeds along 12th Avenue if the road was resurfaced and smooth. Additionally, they were concerned that the proposed crack and seating process would be a noise distraction during construction. MSA worked with the City to host public educational and open-house sessions in which to inform residents about the crack and seating process, ease concerns and gain greater public approval.

Crack and seat is a cost-efficient method that provides a smooth new street surface without a full reconstruction. The purpose is to minimize the occurrence and severity of reflection cracks in the overlay caused by slab movement. This is achieved by first cracking the concrete slabs to reduce their effective size, and then seating the cracked slabs to reestablish support between the subbase and slabs. Once in place, the street is resurfaced and smoothed. Reflection cracks can still occur over time, but the crack and seat method is considered very effective in reducing reflective overlay cracking.

The result of the 12th Avenue project was the rehabilitation of 1,900 feet of pavement, with new ADA-compliant sidewalk ramp upgrades and a full depth repair at the intersection of Twelfth Avenue and Eisenhower Road. The project was completed under a condensed time frame and finished prior to the end of 2019 as the City desired.