Abstract
This paper aimed to determine the softening laws and fracture toughness of slag-based geopolymer (SG) concrete and mortar (SGC and SGM) as compared to those of Portland cement (PC) concrete and mortar (PCC and PCM). Using three-point bending (TPB) tests, the load vs. mid-span displacement, crack mouth opening displacement, and crack tip opening displacement curves (P-d, P-CMOD, and P-CTOD curves) were all recorded. Bilinear softening laws of the PC and SG series were determined by inverse analysis. Furthermore, the cohesive toughness was predicted using an analytical fracture model. The cohesive toughness obtained by experimental study was consistent with that predicted by analytical method, proving the correctness of the tension softening law obtained from inverse analysis. In addition, both initial and unstable fracture toughness values of SG mortar were lower than those of PC mortar given the same compressive strength. Moreover, the initial fracture toughness of SG concrete was generally lower than that of PC concrete, whereas the unstable fracture toughness exhibited an opposite trend.
Highlights
Slag-based geopolymer (SG) is an attractive alternative to Portland cement (PC)
The initial cracking load Pini was determined using a graphical method in this study, referring to the load value where non-linearity started on the presents the obtained average load–displacement (P-d) curves [11]
The inverse analysis adopts evolutionary algorithms, which is a biologically motivated iterative stochastic optimization method, and the core concept is to separate the variation of the object to be optimized from its evaluation as we find it in nature
Summary
Slag-based geopolymer (SG) is an attractive alternative to Portland cement (PC) It can reuse the industrial by-product, i.e., ground granulated blast furnace slag (GGBFS), in an efficient way using alkali activation [1,2,3]. It reduces significantly the CO2 emissions produced during the production of PC, making it a greener solution [4,5]. Extensive studies have demonstrated that SG can exhibit similar mechanical strength with or even perform better than PC does in many aspects, including low hydration heat, high early strength, good durability, and resistance to chemical attack [2,6]. SG exhibits a brittle behavior similar to that of PC
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
