Title: Current Challenges in Average Residual Strength Evaluation of K-Silicate-Based Fiber-Reinforced Geopolymer Concrete

Author(s): Harsh Rathod, Rishi Gupta, Chen Yang, Urmil Dave, and Mohit Garg

Publication: Materials Journal

Volume: 115

Issue: 4

Appears on pages(s): 557-564

Keywords: average residual strength; fiber-reinforced geopolymer concrete; flexural toughness; fly ash; geopolymerization; polypropylene fibers; potassium hydroxide; potassium silicate

DOI: 10.14359/51702189

Date: 7/1/2018

Abstract:
The significant CO2 gas emission associated with manufacturing of conventional portland cement and its environmental hazard has led to the development of alternate cement binders, one of which is geopolymer concrete (GC). The research work focused on characterizing GC properties, such as workability, compressive strength, and average residual strength. A fiber reinforced GC manufactured only using fly ash and K-silicate solution alone had poor workability, rapid hardening, low compressive strength, and residual strength at ambient curing conditions. However, for another mixture, the compressive strength was increased by more than three times (from 5.3 to 21.7 MPa [0.77 to 3.15 ksi]) when cured at 60ºC (140°F) for 24 hours. On the other hand, it has been found that GC has more determination capacity than the normal cement concrete. As a result, the current form of ASTM standard C1399 for normal concrete cannot be used for evaluating average residual strength (ARS) of fiber-reinforced GC.