Clarifying early period hydration process of ultra‐low W/B cementitious composite subjected to underwater circumstance

Abstract An innovative method is proposed in this study that combines long sequence precision prediction model with experiments to study how early hydration affects ultra‐low water‐binder ratio cementitious composite (ULWBRCC) properties. To be specific, by using heat release and degree of hydration as variables and introducing various temporal models to analyze the early hydration process, the micro‐ and macroscopic properties of specimens at different ages are assessed in detail. The obtained results can be summarized as follows: The long‐sequence accurate time series model can predict the earliest hydration process of underwater ULWBRCC, and the predicted late‐stage hydration pattern matches the experimental results. The underwater environment optimizes ULWBRCC's hydration process and increases its early compressive strength by 19.6%. The hydration of ULWBRCC is predicted using a time series model in the paper, filling the gap of uncertainty in the earliest performance of underwater rapid repair cement‐based composite materials, and the MSE of the Informer is improved by 92.88% compared with other models.