Bill and Melinda Gates Foundation Courtyard Words: Dan KamysThe Bill and Melinda Gates Foundation Campus features a 70,000-square-foot stone paver plaza, constructed with several Quikrete underlayment and grouting products. Quikrete Sand/Topping Mix was used for the two-inch-thick paver underlayment over a cast-in-place concrete slab for all exterior installations. Quikrete Polymer Modified Veneer Stone Mortar then was mixed and pumped into the one-half-inch paver joints. The veneer stone mortar was factory pre-blended with integral colors to compliment the natural stone colors. Additionally, a white polymer modified veneer stone mortar formulation was manufactured to match an imported German limestone. Quikrete Multi-Purpose Thin Set, a polymer modified thin set, was used for the installation of all interior stone tile. Quikrete Polymer Modified Veneer Stone Mortar exceeds the ASTM C 270 requirements for Type S Mortar and exhibits two-times the sheer bond strength of standard Type S Mortar. The general contractor on the project was Johnston Construction and commenced in March 2010, with completion in September 2010. Quikrete products used included 3,000-pound Sand Topping Mix (447 bulk bags); 50-pound Multi-Purpose Thin Set (5,229 bags); and 80-pound Polymer Modified Veneer Stone Mortar — Colored (966 bags green, 1,050 bags charcoal and 84 bags white).