BCD works with concrete and steel to create custom furniture, countertops, frames, and more. Although they usually mix their own concrete, they were willing and excited to try casting the Ragland conference table out of SMARTUP.
The basic table design was provided by BCD and modified to NCC’s specifications. The table top is approximately 16 ft by 4ft, with openings to accommodate electric and computer data wires from the conference room. All three columns and the arches of the table base are hollow, allowing the cables to connect from the floor through the table’s outlets without being seen. NCC decided to leave the UHPC its natural dark gray color, made even darker by the waterproof sealant applied by BCD after casting.
The table was cast and delivered in two pieces (base and top), then assembled in the conference room. The formwork for the top was simple, consisting of a border for the shape and shear keys along the perimeter to prevent the UHPC from pushing the border outward. The formwork for the base was much more complex to create the hollow columns and rounded arches. It was also heavily reinforced with wood cross pieces, as the pressure head from several vertical feet of UHPC would be large.
SMARTUP provided its material ingredients and a representative to help mix the UHPC. BCD had worked with UHPC and other high flow mixes before, so they were knowledgeable about the process. BCD used their own high-shear vertical shaft mixer to mix the UHPC, and a small pump to move the UHPC from the mixer discharge to the formworks. This was our first experience pumping SMARTUP, and it pumped well albeit slowly. It took approximately 20 minutes to move each batch of 4 cubic feet. The pump was lifting the UHPC nearly 7 ft off the ground and was only approximately 2 inches in diameter, so a larger pump with a lower elevation gain would undoubtedly perform faster.
The table was cast all in one day and the formworks were removed 48 hours later. BCD then applied sealant and used their equipment to transport the two pieces from their shop in Irondale to the conference room at Ragland.