Evaluating Early-Age Volume Change and Performance of Polymer Modified Belitic Calcium Sulfoaluminate (BCSA) Cements: Field and Lab testing

Abstract

Bridge deck cracking is an increasingly prevalent issue, with limited repair times due to mobility and safety constraints restricting the use of conventional high-early-strength concrete (HESC). This study developed a HESC overlay mix using a belitic calcium sulfoaluminate (BCSA) cement-based system and identified key challenges to its reliable field implementation. Four BCSA systems were evaluated for fresh properties, mechanical strength, and durability performance: CSA with Integral Low-PTM (CSAP), CSA with Liquid Low-PTM (LLP), and latex-modified CSA at 25% (LM25) and 100% (LM100) of the standard latex quantity. The CSAP and LLP mixes were applied as overlays on mini-bridge decks to assess their performance and compatibility with existing substrates under simulated field conditions. In laboratory testing, LLP showed comparable or better strength to CSAP, improved durability over the latex-modified mixes, reduced shrinkage, better air content, and acceptable workability. However, on mini-bridge decks, LLP exhibited significant cracking and underdeveloped mechanical properties. While laboratory results indicate potential for both LLP and CSAP, further research is needed to evaluate the long-term durability and mechanical performance under field conditions. A deeper understanding of the interactions between polymer types and air-entraining admixtures is also essential to improve performance and ensure reliable application.