Location: Washington, DC
Award: Architectural
Project Team
Owner: Redbrick LMD Contractor: Miller & Long
Architect: Winstanley Architects
Engineer: SK&A
Concrete: Monumental Concrete Slag Cement: Heidelberg Materials
Whitman-Walker Health (WWH) provides primary medical, behavioral health, and dental care, as well as a range of health-related legal and support services to more than 20,000 individuals and families annually in the greater Washington, DC, USA region. WWH is a nonprofit community center with expertise in HIV/AIDS and LGBTQ+ care. This new facility was built on the St. Elizabeth Campus in Ward 8, which is in an underserved community.
The plot of land allotted for the building is a small triangular shape. To maximize the building’s usable space, the architect built a unique concave building façade that sculpturally curves with the landscape. The partial red stone façade harmoniously blends in with the historical St. Elizabeth’s campus while modernizing the campus architecture.
Slag cement was used in the footings, strap beams, columns, slab-on-ground, shear walls, foundation walls, and miscellaneous concrete. The mixtures contained 40 to 50% slag cement to lower carbon emissions and slow the initial curing process.
Using slag cement helped minimize the thermal differential in large slab placements, helping to avoid thermal cracking. Slag cement also extended the setting times, as temperatures are typically 85 to 100℉ (30 to 38℃) during the summer months in Washington, DC. The 28-day strength exceeded the design strength, and using slag played an integral role in lowering embodied carbon in the project.
Application Type
Application Type | Footings |
% Slag Cement Replacement | 50% |
% Portland Cement | 50% |
% Portland Limestone Cement | |
% Other SCM (if applicable) | |
Aggregate | 67 Gravel |
Water/cement ratio | .48 |
7-day strengths | 2433 psi |
28-day strengths | 4870 psi |
| |
Application Type | Slabs, Columns, Walls |
% Slag Cement Replacement | 40% |
% Portland Cement | 60% |
% Portland Limestone Cement | |
% Other SCM (if applicable) | |
Aggregate | 57 Stone |
Water/cement ratio | .38 |
7-day strengths | 5300 psi |
28-day strengths | 7900 psi |