Many concrete repairs, especially those relying on pigment, initially seem to be a good color match, but do not weather similarly over time. When matching concrete repairs is critical, such as on architecturally significant mid-century modernist buildings and exposed concrete facades, site specific concrete mix designs provide the best long term match to the existing concrete. This process involves matching each constituent ingredient (sand, cement, and course aggregate) in the existing concrete as closely as possible. SGH examined fractured concrete samples and developed trial concrete mixes to evaluate the match. With the knowledge gained from developing the trial mixes, we created a cementitious materials library for our use on future projects.
Profiling the ingredients provides us with a readily accessibly database of sand, coarse aggregate, cement, and alternative cementitious materials that we can refer to as we develop customize concrete mixes.
The initial library we created serves as a starter kit, but we will continue to expand with materials from additional locations and new quarries. We are also looking to study and compare mixes developed with a visual method to those developed using spectrophotometry.
To learn more, contact Lena Currie at HMCurrie@sgh.com.