Title: Development of Concrete with High Early-Stage Strength

Author(s): J. Ambroise and J. Pera

Publication: Symposium Paper

Volume: 217

Issue:

Appears on pages(s): 257-270

Keywords: calcium sulfoaluminate cement; compressive strength; lithium carbonate; polycarboxylate; workability

DOI: 10.14359/12918

Date: 9/1/2003

Abstract:
A new type of high-performance concrete was developed, based on calcium sulfoaluminate cement. It was designed to reach the following requirements: - high workability: slump higher than 200 mm for at least 50 minutes, - high-early strength: 40 MPa, 6 hours after its preparation, and higher than 55 MPa, after 24 hours. Different polycarboxylate-based superplasticizers and accelerators (lithium carbonate, calcium hydroxide, and normal portland cement) were studied. When the mixture does not contain any accelerator, no strength is recorded after 6 hours. The best accelerating mixture is that containing both lithium carbonate and normal portland cement. The cementitious material is composed of 80% calcium sulfoaluminate cement and 20% normal portland cement. The dosage of lithium carbonate is 0.005% by mass of cementitious material. For a cementitious material content of 600 kg/m3 and W/CM = 0.37, the following performances were obtained: - working time: 65 minutes, - compressive strength: 48 MPa after 6 hours, 57 MPa after 24 hours, and 81 MPa after 60 days.