Parking lots are a cost effective alternative to asphalt that saves owners money in lifetime costs. To encourage good construction of concrete parking lots, the American Concrete Institute (ACI) formed Committee 330, Parking Lots, in 1982. The committee's first document, "Guide for Design and Construction of Concrete Parking Lots," was published in December 1987.


Although concrete parking lots are similar to other pavements, there also are important differences. Most current pavement design methods are based on repetitions of moving loads. But parking lots use half their areas for storing static vehicles; moving load repetitions aren't the only design criterion. Parking lots, like floors, have most loads imposed on interior slabs that are supported on all sides by load transfer to adjacent slabs. However, like streets, parking lots are subjected to the environment. Because of these similarities, ACI's guide borrows construction and design methods from floors and streets.


Narrow, closely spaced joints control cracking, reduce slab curling, and enhance load transfer. Deformed tie bars are suggested across the first longitudinal joint from the pavement edge to form a band to confine the slabs.

Remember that a parking lot is much more than a slab to park cars on. It's a system of slabs, joints, curbs, islands, light poles, and drainage facilities. In the most economical project, these components must function together efficiently.