Evaluation of Three-Point Bending Fracture Tests of Selected Concrete: Mechanical Fracture and Acoustic Emission Parameters

Evaluation of Three-Point Bending Fracture Tests of Selected Concrete: Mechanical Fracture and Acoustic Emission Parameters

Abstrakt

Authors focus attention on mechanical fracture and acoustic emission (AE) parameters obtained from records of three-point bending fracture tests on concrete specimens with initial notch. Total nine sets of specimens were tested. Three specimens at the age of 28 days were tested in each set. Concrete of each set of specimens was different in dosage of Portland cement CEM I 42.5 R and amount of used superplasticizer which resulted in different water to cement ratio of particular mixtures. The Effective Crack Model (ECM) was used to evaluate the load vs deflection diagrams to obtain modulus of elasticity, effective fracture toughness and specific fracture energy. Modulus of elasticity, tensile strength and specific fracture energy were also subject of identification via inverse analysis based on artificial neural network, which aim is to transfer the input data obtained from the fracture test to the desired material parameters. Resistance to stable and unstable crack propagation was quantified via evaluation of load vs crack mouth opening displacement diagrams using Double-K fracture model supported by identified parameters. The similar results for fracture toughness obtained by two different methods, ECM and Double-K model, was observed. The AE technique was used to monitor damage process taking place in specimens.

Authors focus attention on mechanical fracture and acoustic emission (AE) parameters obtained from records of three-point bending fracture tests on concrete specimens with initial notch. Total nine sets of specimens were tested. Three specimens at the age of 28 days were tested in each set. Concrete of each set of specimens was different in dosage of Portland cement CEM I 42.5 R and amount of used superplasticizer which resulted in different water to cement ratio of particular mixtures. The Effective Crack Model (ECM) was used to evaluate the load vs deflection diagrams to obtain modulus of elasticity, effective fracture toughness and specific fracture energy. Modulus of elasticity, tensile strength and specific fracture energy were also subject of identification via inverse analysis based on artificial neural network, which aim is to transfer the input data obtained from the fracture test to the desired material parameters. Resistance to stable and unstable crack propagation was quantified via evaluation of load vs crack mouth opening displacement diagrams using Double-K fracture model supported by identified parameters. The similar results for fracture toughness obtained by two different methods, ECM and Double-K model, was observed. The AE technique was used to monitor damage process taking place in specimens.

fracture test, concrete, double-K model, acoustic emission

fracture test, concrete, double-K model, acoustic emission

ŠIMONOVÁ, H.; TOPOLÁŘ, L.; HAVLÍKOVÁ, I.; MATYSÍK, M.; DANĚK, P.; LEHKÝ, D.; KERŠNER, Z.; PAZDERA, L.

2017

28.09.2016

Inštitut za kovinske materiale in technologie

Ljubljana

978-961-94088-0-3

Program and book of abstracts 24th Int. Conf. on Materials and Technology

111

111

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