Study of Aggregate Size Effect on Fracture Toughness of Petreous Macrocomposites (Concrete)

Article Preview

Abstract:

The present study investigates the effect of rock aggregate size on the fracture toughness of a petreous macrocomposite material (concrete). The effect of aggregate size on the fracture properties of concrete was studied by analysing the fracture toughness KIC results obtained using single edge notched beam (SENB) specimens submitted to 4-point bending test. The results were obtained according to the methodology proposed by Srawley and Gross for monolithic ceramic materials. Additionally, the effect of aggregate size has been analysed by performing fractographic examination of unnotched beam specimens also submitted to 4-point bending test. KIc values obtained via linear elastic fracture mechanics (LEFM) theory applied to the fractographic data were comparable to those obtained by SENB method. The obtained results show that the fracture toughness of concrete depends on the aggregate particle size, although KIC is not linearly related with the particle size. Fracture behaviour depends on the interaction between the used mortar (a mixture of portland cement with sand and water) and the different rock (aggregate) particle sizes. This kind of studies allows further extending the knowledge on the failure mechanisms of concrete, which permits to improve the characteristics of these macrocomposite materials by understanding the effects related to the modification of their structure.

You might also be interested in these eBooks

Info:

Periodical:

Materials Science Forum (Volumes 636-637)

Pages:

1342-1348

Citation:

Online since:

January 2010

Export:

Price:

[1] P.M. Amaral, L.G. Rosa and J.C. Fernandes: Assessment of Fracture Toughness in Ornamental Stones, International Journal of Rock Mechanics and Mining Sciences, Vol. 45(4) (2008), p.554.

DOI: 10.1016/j.ijrmms.2007.05.009

Google Scholar

[2] D.J. Green: An introduction to the mechanical properties of ceramics (Cambridge Solid State Science Series, Cambridge University Press, 1998).

Google Scholar

[3] P.M. Amaral: Mechanical Behaviour of Ornamental Stones (Doctor Engineering Thesis, Technical University of Lisbon, Instituto Superior Técnico, Lisboa, 2004).

Google Scholar

[4] J.H. Hanson and A.R. Ingraffea: Standards for fracture toughness testing of rock and manufactured ceramics: What can we learn for concrete?, Journal of Cement, Concrete and Aggregates, Vol. 19(2) (1997), p.103.

DOI: 10.1520/cca10322j

Google Scholar

[5] C. Li and Y. Wai: Fracture Toughness Determination for Marble Using a Round Bar Specimen, International Journal of Rock Mechanics and Mining Sciences, Vol. 27(1) (1990), p.71.

DOI: 10.1016/0148-9062(90)90011-p

Google Scholar

[6] R.J. Fowell and C. Xu: The Cracked Chevron-4otched Brazilian Disc Test - Geometrical Considerations for Practical Rock Fracture-Toughness Measurement, International Journal of Rock Mechanics and Mining Sciences, Vol. 30(7) (1993) p.821.

DOI: 10.1016/0148-9062(93)90029-d

Google Scholar

[7] R.J. Fowell, J.A. Hudson, C. Xu and J.F. Chen, Suggested Method for Determining Mode-I Fracture-Toughness Using Cracked Chevron-4otched Brazilian Disc (CC4BD) Specimens, International Journal of Rock Mechanics and Mining Sciences, Vol. 32(1) (1995).

DOI: 10.1016/0148-9062(94)00015-u

Google Scholar

[8] RILEM Technical Committee 89-FMT: Fracture mechanics test methods for concrete, edited by S.P. Shah and A. Carpinteri (Chapman and Hall, 1991).

Google Scholar

[9] J.E. Srawley and B. Gross, in: Cracks and Fracture, ASTM STP601, American Society for Testing and Materials (1976) p.559.

Google Scholar

[10] J. C Fernandes, L.G. Rosa and C.P. Silva: Kc from Fractography of Al2O3 and Al2O3/ZrO2, Proc. ECERS 2, 2nd European Ceramic Society Conference, Augsburg, Germany, edited by G. Ziegler and H. Hausner, Deustche Keramische Gesellschaft e.V., (1992).

Google Scholar

[11] ASTM C 1322, Standard Practice for Fractography and Characterization of Fracture Origins in Advanced Ceramics (American Society for Testing and Materials, 2002).

Google Scholar

[12] Information on http: /www. sv. vt. edu/classes/MSE2094_NoteBook/97ClassProj/exper/ gordon/www/fractough. html.

Google Scholar