This expedited award for novel research is to investigate construction and design problems of concrete core slipforming with a cross-disciplinary approach. Slipforming is a method of rapidly forming and placing concrete using hydraulic jacking units to raise a custom-made form. It has revolutionized the construction of bridge piers, silos, and building cores. Major problems are: to keep the form level; precise elevation measurements are required; thicker walls pose a stripping problem; construction problems due to the uneven rate of hardening of the concrete itself; precisely locating many different shaped penetrations; and another major construction problem is caused by the fact that the tolerances of the concrete core and steel frame are not compatible. The following ideas will be explored: a) the use of tapered fiberglass block-outs; b) application of vertical and horizontal lasers will be investigated; c) thermocouples embedded in the concrete of winter-constructed slipforms to constantly monitor concrete temperature for curing; d) the effect of varying the forces exerted by each jacks and changing the amount of steel rebar on the top deck to steer the core straight; and e) new ideas for designing embed plates for out of placement of horizontal and vertical directions will be tested. This research is expected to stimulate more creative and innovative construction researches by exploring new methodologies for automation of construction processes. The research activity is not merely a general academic study of core slipforming. The Sundt Corp., which has built the IBM Tower Core, in Atlanta, GA has expressed a strong interest in this research, and has agreed to provide an opportunity to the investigator to study these problems during the next few months, and to explore innovative ideas in the field to maintain the competitiveness of the U.S. slipforming construction in international and domestic markets.
