Novel C-A-S-H/PCE nanocomposites: Design, characterization and the effect on cement hydration

Abstract

Concrete is the most widely used building material in the world. With the development of the modern civil engineering construction, the rapid development of early-age strength of concrete is becoming more and more crucial. Nowadays, the early-age strength of concrete is generally enhanced by thermal curing at high temperature. However, the drawbacks of thermal curing include the high energy consumption and the adverse effect on the long-term strength of concrete, which promotes the development of green and highly-efficient accelerator. During the past decade, it has been found that C-S-H (calcium-silicate-hydrates) nanoparticles could act as the seeds for cement hydration and thus effectively enhance the early-age strength of concrete, which has drawn many research interests due to their economic and environmental benefits. This study proposes novel C-A-S-H (calcium-alumina-silicate-hydrates) nanocomposites by incorporating moderate Al into C-S-H in the presence of PCE (polycarboxylate superplasticizer), and find the formed C-A-S-H/PCE nanocomposites could remarkably promote the dispersion retention ability and the effect on early-age strength development of concrete comparing to traditional C-S-H nanoparticles. Moreover, this study also provides a basis for the production of green and cheap nano-seeding materials based on Al-rich wastes.