Ultrasonic NDT determination of initial and final setting time of cement paste

Petr Misák,Tomáš Vymazal,Dalibor Kocáb,Barbara Kucharczyková,K Kotrasová,E Kormaníková,S Kmeť

doi:10.1051/matecconf/202031000027

Petr Misák, Tomáš Vymazal + Show 5 more

Open Access

https://doi.org/10.1051/matecconf/202031000027

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Journal: MATEC Web of Conferences	Publication Date: Jan 1, 2020
Citations: 4	License type: CC BY 4.0

Affiliation: Brno University of Technology

Abstract

There are several methods for determination of the setting and early hardening in the cementitious composites. The most common method is using the Vicat apparatus. The major disadvantage of this method is that it is invasive and therefore the measurement results exhibit high variability. The paper deals with the continual monitoring of the process of setting and early hardening of a cement paste using the ultrasonic measurement. The innovative method of using the ultrasonic NDT method for determination of the setting times of cement paste is presented in the paper.

Highlights

The process of setting and hardening of binders is a complex process influenced by internal chemical and physical processes and external curing conditions
The aim of this paper is to present the possibilities of using the ultrasonic pulse method for continuous monitoring of the process of setting and hardening of cement paste by Vikasonic apparatus
In the case of CEM I 42.5 R cement, the value of Initial setting time (IST) obtained using the Vikasonic apparatus corresponds very well to the IST given in the technical sheet of cement

Summary

Introduction

The process of setting and hardening of binders is a complex process influenced by internal chemical and physical processes and external curing conditions. It is known that the setting times of cement (binder) are different from the setting times of the final product, such as mortars or concrete [1]. There are several standardized methods for determining the setting time of binders, mortars and concrete [3,4,5,6]. All mentioned methods are based on the measurement of the penetration depth of the penetration needle (testing of binders) or resistance against penetration (testing of mortars and concrete). The most widely used and standardized method for determining the setting times of cement is using the Vicat apparatus according to EN 196-3 [3]. The setting time is considered as a time after which the needle penetrates the cement paste of normal consistency to the specific depth [3]

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