GSC South River Tunnel

CTLGroup was engaged by GSC Atlanta to provide materials consulting for the South River Tunnel Project. Our team developed structural concrete mixtures, first “on-paper” then in our laboratory using the information provided, which included: the project specifications, the client’s input, property data for aggregates, available admixtures, and available cementitious material mill certifications.

Our team used their expertise to provide concrete mixtures to meet the assumed and stated needs of the project based on the design strengths requested. The concrete was developed to be flowable based on the stated pumping requirements. The client visited our laboratory during the batching of the concrete mixtures to verify the trial batches were consistent with the requirements. Our client also participated in the trial batching process. The concrete batching and fresh property testing was performed in the CTLGroup laboratory to verify that the on-paper mixtures obtained sufficient workability and mechanical properties. We assessed workability, flowability, compressive strength, time of set, and drying shrinkage for selected mixtures.


Civil Infrastructure

Water and WasteWater

Consulting Services

Concrete + Cement-Based Materials

Concrete Mixture Development & Qualification

Durability & Service Life

Project Specification Review & Development

Mass Concrete & Thermal Control

Rheology, Pumpability, and Constructability

Laboratory Services

Concrete + Cement-Based Materials

Durability & Service Life

Specialized Testing

As part of the $4-Billion Clean Water Atlanta Program, the city constructed the tunnel to collect water flows from sanitary sewers and transport them to a newly constructed, pumping station.


Project Completion

111 M

Project Cost

9,000 FT

Tunnel Length

Learn more about this project

Project Detail Form

Project Detail Form