Location: Milwaukee, Wisconsin
Award: High Performance
Project Team
Owner: Hines
Contractor: W.E. O'Neil Construction
Architect: Solomon Cordwell Buenz (SCB)
Concrete: Riv/Crete Slag Cement: St Marys Cement

This project created a new public access point to the Milwaukee RiverWalk in Milwaukee, WI, USA, by extending the existing path to the corner of St. Paul Avenue and Water Street, providing a connection to the nearby Milwaukee Public Market. The ground level comprises 10,000 ft2 (930 m2) of retail, including space envisioned for a restaurant with significant outdoor seating along the river. Matching its address, the project offers 333 apartment units, ranging from studios to three-bedrooms and penthouses.
Though clearly delineated from the surrounding district by its height, the project’s design was heavily influenced by the architectural character of the Third Ward. The variegated colors and textures of brick, fine-crafted metal detailing, and varying scales of the historic context are reflected within the tower’s modern design. Oriented along the St. Paul Avenue axis to minimize its impact on the roofline of the historic district, it features a layered, industrial-like composition of brick, precast, metal panel, and glass. Along Water Street, a seven-story screened parking structure was intentionally designed to appear as a separate structure, serving as a stylistic transition between old and new.
Slag cement was used throughout the project, including in a 6000 psi (41 MPa) air-entrained mixture for the post-tensioned deck of the parking structure. Slag cement was selected for its durability characteristics, low carbon footprint, and consistent water demand and strength characteristics. The mixture for the parking structure comprised portland-limestone cement and slag cement at a 14.5% cement replacement level. While low water-cementitious materials ratios (w/cm) and high dosages of polycarboxylates can cause sensitivity and fluctuations in total air content, slag cement’s consistency results in a low variability of air entrainment dosage rates from placement to placement.
The deck mixture had an average compressive strength of 7200 psi (50 MPa) at 28 days, exceeding project specifications and allowing the project to remain on schedule.
The project specifications required 8000 and 10,000 psi (55 and 69 MPa) in 56 days for columns and core walls. The cement replacement levels for these mixtures was 9.3% and 12%, respectively. Slag cement was selected for these high-strength applications due to its consistency in short term and long-term strength gain along with its natural water-reducing properties. These mixtures needed to be pumped 31+ stories through hard pipe and a placing boom. Slag cement helped to increase paste volume while providing a placeable and workable mixture.
Application Type
Application Type | Exterior PT Deck Mix |
% Slag Cement Replacement | 14.5% |
% Portland Cement | |
% Portland Limestone Cement | 85.5% |
% Other SCM (if applicable) | |
Aggregate | 3140 |
Water/cement ratio | .36 |
7-day strengths | 5690 psi |
28-day strengths | 7290 psi |
Application Type | 8,000 psi Columns |
% Slag Cement Replacement | 9.3% |
% Portland Cement | |
% Portland Limestone Cement | 65.8% |
% Other SCM (if applicable) | 24.9% |
Aggregate | 3060 |
Water/cement ratio | .31 |
7-day strengths | 7630 psi |
28-day strengths | 9900 psi |
Application Type | 10,000 psi Columns |
% Slag Cement Replacement | 12% |
% Portland Cement | |
% Portland Limestone Cement | 64% |
% Other SCM (if applicable) | 24% |
Aggregate | 3040 lbs. |
Water/cement ratio | .31 |
7-day strengths | 8960 psi |
28-day strengths | 11540 psi |
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