Reassessing early-age strength development of high-volume fly ash concretes for precast buildings
- Illinois Institute of Technology, Chicago, IL (United States)
- Valparaiso University, IN (United States)
Increasing beneficial use of fresh or landfilled fly ash as a replacement for Portland cement can be more challenging for the construction of precast buildings or similar applications requiring rapid strength development. Therefore, the framework presented in this paper aims to reassess high-volume fly ash concretes but in the context of facilitating more sustainable precast buildings. More specifically, the framework was used to characterize strength development of concrete mixes with a target minimum 24-hour compressive strength of 24.1 MPa (3500 psi), selected as an example strength development metric to demonstrate the framework, and comprised of 40% Class C, Class F, and landfilled (harvested) fly ash – as a high-volume replacement of Type III or Type IL cement. High-early strength was driven by optimized dosages of commercial grade gypsum and accelerating admixtures, in addition to optimal aggregate packing and mix proportioning strategies. Early-age mechanical properties including compressive strength, modulus of rupture, and modulus of elasticity were reevaluated within 24 hours of batching with respect to common precast production demands. Simple data analyses were then used to highlight cases where currently accepted design provisions for the aforementioned properties are either overly-conservative or unconservative with respect to test data. Furthermore, the framework and demonstration of example mixes presented herein aim to promote confidence for using larger fractions of fresh or landfilled fly ashes for precast buildings to further enhance environmental benefits without sacrificing pertinent early-age structural performance.
- Research Organization:
- Illinois Institute of Technology, Chicago, IL (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- FE0031931
- OSTI ID:
- 2496678
- Alternate ID(s):
- OSTI ID: 2497364
- Journal Information:
- Journal of Building Engineering, Journal Name: Journal of Building Engineering Vol. 100; ISSN 2352-7102
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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