The Buckhorn Office Building uses a curtain wall system comprised of several different materials. The majority of the façade is comprised of a metal panel system using 5 different colors of panels. The panels come in 4’ x 4’ sections and are attached to an underlying EIFS backing system. The metal panels are accompanied by rigid metal paneling that is constructed in 25’ increments and covers the top two-thirds of the building. This rigid metal paneling is also attached to the skin of the building via an underlying EIFS backing system. Along with metal panel construction, there is an architectural feature located at the front entryway that uses a more complex curtain wall layout comprising of metal panels, anodized aluminum mullions and glazing. The glazing used for the curtain wall is insulated and tinted. The glazing is provided by Atlantica and is Low E glazing. This curtain wall feature runs vertically from the front entrance to the roof.

Structural Steel Frame
The structural system of the Buckhorn Medical Office Building is structural steel. The floor system is a 1.5-inch 20 gauge composite deck with 2.5 inches of normal weight concrete topping. The decking is reinforced with 6x6 W2.1xW2.1 WWF. The total floor thickness is 4 inches. The roof construction consists of 1.5-inch, 20 gauge, Type “B” metal roof decking with 2 layers of 2-inch rigid insulation installed with staggered joints. On top of the rigid insulation is a fully adhered Sur-Weld (TPO) roof membrane. The roof’s 30 PSF snow load is supported mainly by 24K5 K-Series joists with W21x50 girders along the north and south elevations and W18x35 girders along the east and west elevations. Throughout the main building typical W18x35 beams sit on W24x76 girders. Typical W10x39 columns are placed in 30’x30’ bays across the entire building footprint. W10x68 columns are used at the elevator shafts and stairwells. Located along the northern and southern elevations, two types of x-bracing are used. Two HSS4x4x3/8 AESS cross brace on all three floors (2 per floor) along the north and south elevations in one bay. Two 4x4x1/2 angles cross brace on all three floors along the north and south elevations in one bay as well. The entrance canopy is supported by three C12x20.7 girders and six W12x19 beams.

The crane being used for all steel placement is a Kobelco CK850-III hydraulic crawler crane with a maximum lift capacity of 75 tons and a max boom length of 200 feet. The crane starts by placing all of the columns and then works from west to east placing all of the girders and then again placing all of the beams. Due to the low total height of the building (43’-0”) there are no logistical issues placing any pieces of steel with the provided crane. No additional overhead protection is necessary due to the size of the site during crane picks.

Cast-in-Place Concrete
Most of the cast-in-place concrete is used in the pouring of the spread footings. 12’x12’x2’-4” spread footings are placed at 30’x30’ bays. The exterior walls are supported by 3’ strip footings with a 1’ foundation wall on top of it that connects the perimeter spread footings. All foundation concrete is 3000 PSI with 5% air entraining and a 4-inch slump. Reusable plywood forms and 2x4s are used for all foundation formwork. The slab-on-grade consists of a 5-inch concrete slab with 6x6W2.9xW2.9 WWF over compacted 2A sub-base over a 10 mil vapor barrier. The second and third floors also have a concrete slab poured on a 1.5-inch 20 gauge composite deck. All slab concrete is 3500 PSI with a 4-inch slump. All foundations are placed by direct chute from the truck, and all decks are placed by pump. All foundations are then mechanically vibrated to ensure proper aggregate and air settlement.