O'Fallon staff urges council to allow asphalt PDR in residential streets to address ACR damage

City street-maintenance staff outlined a multi-pronged approach to persistent pavement damage at a June 26 workshop and asked the O'Fallon City Council to let crews resume asphalt partial-depth repairs (PDR) on residential streets.

Mister Bender, the city's pavement presenter, told the council some neighborhoods are “suffering from a condition called alkali carbonate reaction, ACR,” a chemical process in older concrete that “peels the slab apart from the inside.” He showed photographs of Country Orchard Drive and other streets to illustrate how ACR damage propagates through a slab and causes repeated failures.

Bender walked council members through the city’s toolbox of maintenance options — crack sealing (preventative, done on a five‑year rotation at roughly $300,000 annually), pothole patching, TechCrete rubberized joint repairs (city budgeted about $1,000,000 per year in contracted TechCrete work and $150,000 for in‑house material), asphalt and concrete partial‑depth repair (PDR), and full slab replacement (budgeted at roughly $4,000,000 per year for contracted slab work). He presented per‑100‑foot cost and time comparisons the staff uses to weigh options and life‑cycle value: crack sealing at about $100 and roughly 10 minutes per 100 feet; asphalt PDR near $1,800 and about two hours per 100 feet; and full slab replacement near $23,000 and multi‑day work.

The central policy question for the council was whether to restore asphalt PDR on residential streets after a 2017 council direction halted that practice because some residents objected to the visual contrast of asphalt repairs in concrete subdivisions. Bender said the city stopped using asphalt PDR in subdivisions because “it looked terrible,” but argued the technique is “economical and better for the community” and can last substantially longer than repeated pothole patches.

Councilmember Taylor pressed staff on alternatives such as spray‑injection pothole repair, noting federal guidance and the need for durable fixes. “This spray injection seemed to be something that was better than just filling,” Taylor said; Bender replied that staff would research spray injection and that “all of these are like tools in a toolbox” to be used where appropriate.

Multiple council members — including Ragsdale and Bibb — voiced practical support for returning to asphalt PDR in appropriate residential contexts, noting cost and longevity advantages and examples from streets where repeated work orders have been required. Staff said a policy change would not require an immediate ordinance vote; instead, implementation and funding would be handled through future budget and CIP approvals.

Next steps: staff will research additional techniques raised by council (including spray injection), refine cost and scope estimates, and return implementation details through the city’s budgeting and CIP process.