The Effect of a Superplasticizer Admixture on the Mechanical Fracture Parameters of Concrete.

článek v časopise ve Web of Science, Jimp

angličtina

This paper focuses on the mechanical fracture parameters obtained from records of three-point bending tests on concrete specimens with a central edge notch. The tests were conducted on four sets of specimens made of different materials. The concrete of the specimens was different in the dosage of Portland cement CEM I 42.5 R (305 kg/m3 or 355 kg/m3) and superplasticizer (none or 0.25 % of the mass of the cement). The consistency class of fresh concrete determined using a slump test and a flow-table test was the same for all the mixtures. Three specimens in each set were tested after aging for 28 d. Increasing the dosage of cement and superplasticizer admixture influences the mechanical fracture properties of the concrete in both positive and negative ways. It follows that it is proper to monitor not only the effect of the superplasticizer admixture on the compressive strength values, but also focused attention on the fracture parameter values. The resistance to stable and unstable crack propagation, which is evidently connected with the durability of material, was quantified using a double-K fracture model.

concrete, mechanical fracture parameters, superplasticizer, fracture test, double-K model

ŠIMONOVÁ, H.; HAVLÍKOVÁ, I.; DANĚK, P.; KERŠNER, Z.; VYMAZAL, T.

2015

15. 5. 2015

Institute of Metals and Technology

Ljubljana

1580-2949

Materiali in tehnologije

49

3

Slovinská republika

417

421

5