Mix Design Levers and Decision Points-Mix Design Levers and Decision Points- part 3

Video Transcription

Video Summary

In this PCI webinar, Charles Munn, Director of Concrete Sustainability at Master Builders Solutions, discusses innovations in producing low embodied carbon precast concrete while maintaining or improving performance. As the construction industry globally aims for net zero carbon emissions by 2050, there is a growing focus on using low-carbon binders, supplementary cementitious materials (SCMs), and admixtures. Key challenges in low carbon mixes include increased water demand, stickiness, delayed set times, and difficulty achieving early stripping strength critical for precast production schedules.<br /><br />Munn highlights two innovative admixtures to address these issues: a calcium silicate hydrate (CSH) nanoparticle-based strength-enhancing admixture, which accelerates hydration and boosts early and late strength, allowing reductions in Portland cement content; and a rheology modifying water-reducer that lowers concrete viscosity, improving flow, workability, finishability, and surface appearance, especially in low-slump applications like hollow core planks.<br /><br />Practical application examples demonstrate how these admixtures enable compliance with GWP and Portland cement limits while attaining required strengths and quality in precast elements. Munn emphasizes the importance of regional SCM knowledge, rigorous trialing, and collaboration with suppliers to optimize mixes for sustainability goals. The presentation concludes with encouragement to leverage PCI’s sustainability resources and engage with ongoing industry efforts to advance lower carbon concrete solutions.

Keywords

low embodied carbon concrete

precast concrete

calcium silicate hydrate nanoparticles

rheology modifying admixtures

supplementary cementitious materials

net zero carbon emissions

concrete sustainability

low carbon concrete mixes