This Week's Featured Presentation
New Innovations in Chemical Admixtures (ACI Spring 2018 Convention, Salt Lake City, UT) Since the introduction of polycarboxylate based high-range water reducers in the mid-1990s, scientists have made significant progress in the design of polymer structures and the ability of these polymers to affect the performance of concrete. Advances in the understanding of the polymer structure and its relationship to the performance in concrete have expanded the capabilities of new generation high-range water reducers to incorporate a broader range of design criteria and applications. From speed of dispersion to rheology improvement, polymers are developed to meet the demanding placement conditions of concrete contractors and the high-performance specifications from architects and engineers. The science of polymer design has grown to a purposeful manipulation of the polymer structure at the molecular level and has pushed these materials to achieve performance beyond the apparent performance boundaries. Maximizing dispersion speed, extending workability retention without impacting initial workability or causing adverse effects on time of setting or early-age compressive strength, and positively influencing the rheological properties of concrete are among some of the most recent technological developments in polymer-based high-range water reducers. This presentation will cover new polymer innovations and how they are being used to address the needs of concrete producers to improve operational efficiency, maximize contractors’ placement ability, and enable architects and engineers to expand design potential. These polymer innovations are challenging the industry to re-think high-range water reducer performance expectations.
March 2 - 8
A New Generation of Micro-Particulate-Based Admixtures for Concrete
by Christopher John Eagon, BASF; and Paul Horst Seiler, BASF Corp.
New Innovations in Chemical Admixtures (ACI Spring 2018 Convention, Salt Lake City, UT) In recent years, there has been significant research and product development in the field of nanotechnology – using particles of approximately 1 and 100 nm in size. From medicines, to electronics and coatings, the answers to ‘big problems’ are being provided by ‘tiny solutions.’ In the cement and concrete field, nano-structural models of Calcium Silicate Hydrate (C-S-H), have allowed researchers to develop particles to improve and increase C-S-H formation. The practical challenge continues to be how to introduce these micro- and nanoscale particles into the concrete matrix. A logical option is in the form of a liquid admixture added to the concrete mixture during batching. This presentation will focus on the current and emerging micro- and nanoscale particulate-based admixture technologies for concrete and their effects on the hydration process and long-term durability of concrete. The information to be presented will show that the use of these particulate-based liquid admixtures offer different options for modifying and improving the fresh, hardened and durability properties of concrete.