Benefits of using super absorbent polymers in concrete
Super absorbent polymers (SAP) are of increasing interest in the concrete industry. SAP is delivered as a dry powder into the concrete mixer, and the particles are capable of absorbing water about 20-30 times their own weight. The swollen SAP particles hold on to the water during mixing and placement, but give up the water after concrete hardens and after the water of convenience has been used or evaporated. In this way, SAP functions as an internal curing technology similar to porous lightweight aggregates. Benefits include suppression of drying shrinkage, improved durability, and more convenient curing options that can avoid steps such as burlap blankets and water sprinkler systems. SAP is particularly attractive for high performance concrete with lower w/c ratio and applications such as large flat slabs that are vulnerable to drying shrinkage cracking. This presentation will include methods to calculate dosage, lab results demonstrating benefits, and best practices for use in field applications.
David A. Lange, FACI, is Professor Emeritus of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign, Urbana, IL. Lange served as ACI President in 2018-19, and continues service on the ACI Board of Direction. His past positions include Chair of the ACI Technical Activities Committee, Chair of the Publications Committee, and Chair of the Board Outlook 2030 Task Group. Lange received the ACI Wason Medal for Most Meritorious Paper in 2003, 2018, and 2020. Lange is a Fellow of the American Ceramic Society and he received a J. William Fulbright Scholar Award in 2013. Lange holds degrees from Northwestern University (PhD, 1991), Wichita State University (MBA, 1984), and Valparaiso University (BSCE, 1981).