Fast Setting, Low Carbon Infrastructure Rehabilitation Using Belitic Calcium Sulfoaluminate (BCSA) Concrete

Abstract

Rapid-setting binders such as Belitic Calcium Sulfoaluminate (BCSA) are increasingly important as the demand for rehabilitation and fast return to service of roads and bridges grows. Speed of construction, low shrinkage, and low carbon footprint are the key features of BCSA concrete. The binder was first developed in the United States in the mid-seventies. It allows pavement, bridge decks or other concrete infrastructure to be replaced and returned to service in a matter of hours. BCSA concrete slabs placed at the Seattle International Airport (SEA) in the 1990s are still in service 20 years later. The binder also allows innovation in pavement design. Taking advantage of the low shrinkage of BCSA concrete, a single 40 ft x 40 ft airport slab without joints was placed at this airport, as an alternative to the placement of four contiguous conventional-size portland slabs. BCSA was also to be the basis for the design of various rapid-setting performance-engineered concretes, such as low-permeability or UHPC concrete. This paper will review recent concrete applications based on BCSA cement, and the opportunities they offer in building a more resilient, lower carbon concrete infrastructure.