Mechanical Fracture and Fatigue Characteristics of Fine-Grained Composite Based on Sodium Hydroxide-Activated Slag Cured under High Relative Humidity

Hana Šimonová,Martin Lipowczan,Vlastimil Bílek,Lucie Malíková,Petr Miarka,Barbara Kucharczyková

doi:10.3390/app11010259

Hana Šimonová, Martin Lipowczan + Show 4 more

Open Access

https://doi.org/10.3390/app11010259

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Journal: Applied sciences	Publication Date: Dec 29, 2020
Citations: 7	License type: CC BY 4.0

Affiliation: Brno University of Technology

Abstract

A typical example of an alternative binder to commonly used Portland cement is alkali-activated binders that have high potential as a part of a toolkit for sustainable construction materials. One group of these materials is alkali-activated slag. There is a lack of information about its long-term properties. In addition, its mechanical properties are characterized most often in terms of compressive strength; however, it is not sensitive enough to sufficiently cover the changes in microstructure such as microcracking, and thus, it poses a potential risk for practical utilization. Consequently, the present study deals with the determination of long-term mechanical fracture and fatigue parameters of the fine-grained composites based on this interesting binder. The mechanical fracture parameters are primarily obtained through the direct evaluation of fracture test data via the effective crack model, the work-of-fracture method, the double-K fracture model, and complemented by parameter identification using the inverse analysis. The outcome of cyclic/fatigue fracture tests is represented by a Wöhler curve. The results presented in this article represent the complex information about material behavior and valuable input parameters for material models used for numerical simulations of crack propagation in this quasi-brittle material.

Highlights

Accepted: 25 December 2020 Portland cement and its blends are and in the near future will be the most common binders in practical applications around the world because of their availability, versatility, and tradition, there are increasing efforts to search for some alternative binders.A typical example is alkali-activated binders that have high potential as a part of a toolkit for sustainable construction materials, especially in applications where resistance to elevated temperatures or aggressive environments is required [1]
The main aim of the present research is to investigate the long-term mechanical, fracture, and fatigue behavior of a fine-grained composite based on sodium hydroxideactivated slag under relative humidity (RH) ≥ 95%
The structures made of quasi-brittle materials are usually loaded in a mixed-mode manner in civil engineering applications; the attention in the performed experimental campaign was focused on this issue

Summary

Introduction

A typical example is alkali-activated binders that have high potential as a part of a toolkit for sustainable construction materials, especially in applications where resistance to elevated temperatures or aggressive environments is required [1]. One group of alkali-activated materials is alkali-activated slag (AAS), which sets and hardens rapidly even at room temperatures and reaches high strengths [2]. There is a lack of information about the long-term properties, fracture characteristics, or fatigue of AAS. Its behavior is characterized most often in terms of its compressive strength; this is not sensitive enough to sufficiently cover the changes in microstructure such as microcracking, and it poses a potential risk for practical utilization. The present study deals with the determination of long-term mechanical fracture and fatigue parameters of the fine-grained composites based on this interesting binder

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Conclusion