Cracking, bond, and durability performance of internally cured cementitious grouts for prefabricated bridge element connections

Abstract

The use of cementitious grouts in prefabricated bridge element (PBE) connections is a common practice in the USA. Given the important role that these connections play within the infrastructure, the grout materials used must provide good flowability, mechanical and durability properties, low shrinkage, and good bond to the precast concrete element. However, this type of grout material has shown serviceability issues in the form of volume instabilities (primarily shrinkage). The inclusion of internal curing (IC) in cementitious grouts with the goal of reducing shrinkage has been successfully demonstrated in a previous study. The research presented in this paper extends upon that prior study and assesses the IC effect on properties relevant to PBE grout connections. The paper uses novel experimental techniques such as the dual ring test, formation factor concepts, and microstructural analysis to evaluate improvements in cracking, bond, and durability performance. The results show that, while the IC grouts did not alter the bond performance, they improved their cracking and durability properties. The inclusion of IC in cementitious grouts is presented here as a strategy to increase the durability and thus sustainability of bridge structures.