Performance Criteria for Ready Mixed Concrete: Where Are We Today? (Part 2)-Performance Spec Concrete for a Super-Tall Building (PDF)

Performance Spec Concrete for a Super-Tall Building (PDF)

Pdf Summary

The document outlines the specifics and challenges encountered in constructing a super-tall building, the Vista Tower, using performance-specification concrete. Scheduled to open in April 2020, this 103-story building includes a luxury hotel, condos, and a parking garage, with significant emphasis on using 115,000 cubic yards of concrete. Importantly, concrete deliveries involved 12,800 truckloads and 11,500 tons of rebar.<br /><br />The project required varied concrete mixes tailored to different structural needs and conditions, including temperature, workability, and congestion in dense environments. A critical parameter was the Modulus of Elasticity, essential for the structural integrity of this narrow and tall building. Extensive collaboration took place between structural engineers, builders, and suppliers to ensure concrete met rigorous specifications.<br /><br />ACI 301 revisions facilitated the use of high-slump, highly flowable concrete, accommodating the high pumping rates necessary for tall structures. Mass concrete requirements necessitated individual thermal protection plans due to the substantial sizes of elements like mats, grade beams, and silo walls. The AHS (Adiabatic Heat Signature) was used for simulations predicting temperature outcomes during curing.<br /><br />Mass concrete criteria included conducting a rapid physical testing program to assess risks of DEF (Delayed Ettringite Formation) based on the chemistry of cementitious materials. The construction method involved using wireless sensors for real-time temperature and maturity monitoring of concrete, ensuring safe curing conditions.<br /><br />Test blocks were utilized to refine techniques and confirm simulation predictions under extreme conditions. Foundations and walls were meticulously planned and executed, focusing on structural integrity and thermal management. In summation, the project demanded innovative thinking, rapid information processing, and collaborative efforts for successful completion.

Keywords

Vista Tower

performance-specification concrete

super-tall building

Modulus of Elasticity

high-slump concrete

mass concrete

thermal protection

wireless sensors

structural integrity

collaborative efforts