iStock.com/Marcus Lindstrom In 1962, retailers began building large suburban stores surrounded by parking lots, and the “big-box” store was born. Since then, supercenters and megastores have continued to achieve success in the retail environment. Aside from their eponymous big and boxy design, big-box stores have several identifying features: they are usually single-story structures with warehouse-style construction, have few interior columns (thus maximizing floor space), and have a concrete slab foundation. One of the largest online retailers…has added a requirement for ACI commercial/industrial flatwork finishers on every project. The concrete slabs often measure 100,000 sq. ft. or more and require sophisticated construction methods compared to conventional floors. Floor flatness is a critical consideration because the floors must accommodate ultra-high-density, tall-rack storage. Warehouse sections within big-box buildings may have the additional demands of narrow aisles. Robotic equipment, ultra-high-density, and buffering systems, as well as wire-guided lift trucks, may need to operate along pre-defined paths. Also to be considered are the demands from extreme loading via heavy installed equipment in addition to loading from stocked items.