Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7883540 | Cement and Concrete Composites | 2018 | 45 Pages |
Abstract
This paper aims to advance research on the use in concrete of a high volume of fly ash, with a high loss on ignition value, aiding in sustainable low carbon footprint construction. To this end, the work explores the benefits that may be achieved in terms of long-term concrete performance from the incorporation of fly ash along with a chemical activator. Durability tests are performed on concrete with an activated hybrid cementitious system: Portland cement (PC) and high volume fly ash with sodium sulfate. The chloride diffusion coefficient significantly decreased over time for the activated system (50% PC - 50% fly ash with added sodium sulfate) compared to the control samples (100% PC and 80% PC - 20% fly ash) at the same water to cementitious material ratio. This behavior is particularly evident in samples cured under controlled laboratory conditions (100% RH and 23â¯Â°C). However, outdoor curing increases the permeability for all concretes. Long term carbonation is also investigated under natural exposure conditions, and samples that are cured outdoors exhibit a significant carbonation depth. The compressive strength is correlated with the durability parameters: the durability performance improves as the compressive strength increases, indicating that as is the case for Portland cement (but not always for alkali-activated binders), the microstructural factors which yield high strength are also contributing to durability properties.
Related Topics
Physical Sciences and Engineering
Engineering
Industrial and Manufacturing Engineering
Authors
Diego F. Velandia, Cyril J. Lynsdale, John L. Provis, Fernando Ramirez,