Evaluation of Fracture Mechanics Parameters of Light-weight Concrete by Implementing Natural Pumice Stone as Coarse Aggregate

1, a  Azhar Jawad Nimat     2, a  Azad Abdulkadir Mohammed  3, a  Ahmed Salih Mohammed  

a  University of Sulaimani, College of Engineering, Civil engineering Department


The concrete material softening response curve is essential for accurate numerical analysis of concrete. The tensile strength, initial fracture energy, and total fracture energy are the three parameters of interest in defining such softening response. Among them, the fracture energy is usually regarded in any analytical program that attempts to model reinforced concrete (RC) structures' behavior. The brittleness and fracture characteristics of lightweight concrete (LWC) produced from 19 mm maximum size natural pumice stone aggregate were investigated via testing notched beam specimens under three-point bending test. Fracture parameters were analyzed and explained using the size effect method (SEM) and the work of fracture method (WFM), and the results were compared to those found in the published literature. The results show mean total fracture energy (GF) of 145.65 N/m and a mean characteristic length (Lch) of 590.34 mm. Later, by correlating the result obtained via this method to the SEM approach, the initial fracture energy (Gf) was determined with a mean value of 58.26 N/m and the fracture toughness (KIC) was found to be 38.47 MPa.mm0.5. Lightweight concrete was found to be more ductile and need more energy to propagate fracture across the specimen, as shown by a comparison of current data to that acquired from literature.


Fracture mechanics; Notched beam; Lightweight concrete, Work of fracture method.



[1] A. Abolhasani, H. Nazarpour, M. Dehestani, The fracture behavior and microstructure of calcium aluminate cement concrete with various water-cement ratios. Theoretical          and Applied Fracture Mechanics, 109 (2020) 102690.

[2] M. Karimaei, F. Dabbaghi, A. Sadeghi-Nik, M. Dehestani, Mechanical performance of green concrete produced with untreated coal waste aggregates, Construction and               Building Materials, 233 (2020) 117264. 

[3] F. Dabbaghi, M. Dehestani, H. Yousefpour, H. Rasekh, S. Navaratnam, Residual compressive stress–strain relationship of lightweight aggregate concrete after exposure to           elevated temperatures, Construction and Building Materials, 298 (2021) 123890.

[4] K.S. Youm, J. Moon, J.Y. Cho, J.J. Kim, Experimental study on strength and durability of lightweight aggregate concrete containing silica fume, Construction and                       Building Materials, 114(2016) 517-527.

[5] V. Nežerka, P. Bílý, V. Hrbek, J. Fládr, Impact of silica fume, fly ash, and metakaolin on the thickness and strength of the ITZ in concrete, Cement and concrete                            composites, 103 (2019) 252-262.

[6] F. Dabbaghi, H. Fallahnejad, S. Nasrollahpour, M. Dehestani, H. Yousefpour, Evaluation of fracture energy, toughness, brittleness, and fracture process zone properties for         lightweight concrete exposed to high temperatures, Theoretical and Applied Fracture Mechanics, 116 (2021) 103088.

[7] A.S. Rao, G.A. Rao, Fracture mechanics of fiber reinforced concrete: an overview. International Journal of Engineering Innovations and Research, 3(4) (2014) 517.

[8] Z.P. Bazant, J. Planas, Fracture and size effect in concrete and other quasibrittle materials. Routledge (2019).

[9] Y.S. Jenq, S.P. Shah, Features of mechanics of quasi-brittle crack propagation in concrete. In Current trends in concrete fracture research (pp. 103-120). Springer,                        Dordrecht (1991).

[10] J. Sri Kalyana Rama, M.V.N. Sivakumar, A. Vasan, C. Garg, S. Walia, A review on studies of fracture parameters of self-compacting concrete, Advances in Structural                  Engineering, (2015) 1705-1716.

[11] M.H. Beygi, M. T. Kazemi, I.M. Nikbin, J.V. Amiri, The effect of water to cement ratio on fracture parameters and brittleness of self-compacting concrete. Materials & Design, 50 (2013) 267-276.

[12] J.Z.G. Choi, S. Hino, K. Yamaguchi, S. Kim, Influence of fiber reinforcement on strength and toughness of all-lightweight concrete, Construction and Building Materials, 69 (2014) 381-389.

[13] Z. Shi, Crack analysis in structural concrete: theory and applications. Butterworth-Heinemann (2009).

[14] D. Roylance, Introduction to fracture mechanics (2001).

[15] L. Reis, M. Fonte, M. Freitas, V. Infante, XV Portuguese Conference on Fracture (XV PCF). Theoretical and Applied Fracture Mechanics, (85) (2016) 1.

[16] C. Carloni, Analyzing bond characteristics between composites and quasi-brittle substrates in the repair of bridges and other concrete structures. In Advanced composites in bridge construction and repair (pp. 61-93). Woodhead Publishing (2014).

[17] H. Fallahnejad, M.R. Davoodi, I.M. Nikbin, The influence of aging on the fracture characteristics of recycled aggregate concrete through three methods. Structural                    Concrete, 22 (2021)  E74-E93.

[18] M. Karamloo, M., Mazloom, G. Payganeh, Influences of water to cement ratio on brittleness and fracture parameters of self-compacting lightweight concrete. Engineering           Fracture Mechanics, 168, (2016) 227-241.

[19] H. Salehi, M. Mazloom, an experimental investigation on fracture parameters and brittleness of self-compacting lightweight concrete containing magnetic field treated water. Archives of Civil and Mechanical Engineering, 19(3) (2019) 803-819.

[20] I.M. Nikbin, M. Farshamizadeh, G.A. Jafarzadeh, S. Shamsi, Fracture parameters assessment of lightweight concrete containing waste polyethylene terephthalate by                   means of SEM and BEM methods. Theoretical and Applied Fracture Mechanics, 107 (2020) 102518.

[21]   R. Ince, Determination of concrete fracture parameters based on peak-load method with diagonal split-tension cubes. Engineering Fracture Mechanics, 82 (2012) 100-114.

[22] B.L. Karihaloo, H.M. Abdalla, Q.Z. Xiao, Size effect in concrete beams. Engineering fracture mechanics, 70(7-8) (2003) 979-993.

[23] Y. Yan, Q. Ren, N. Xia, L. Shen, J. Gu, Artificial neural network approach to predict the fracture parameters of the size effect model for concrete. Fatigue & Fracture of Engineering Materials & Structures, 38(11) (2015) 1347-1358.

[24] D.R. RILEM, Determination of the fracture energy of mortar and concrete by means of three-point bend tests on notched beams. Materials and structures, 18(106) (1985) 285-290.

[25] A. Carpinteri, Fractal nature of material microstructure and size effects on apparent mechanical properties. Mechanics of materials, 18(2) (1994) 89-101.

[26] N. Trivedi, R.K. Singh, J. Chattopadhyay, Investigation on fracture parameters of concrete through optical crack profile and size effect studies. Engineering Fracture Mechanics, 147(2015) 119-139.

[27] Z.P. Bažant, E. Becq-Giraudon, Statistical prediction of fracture parameters of concrete and implications for choice of testing standard. Cement and concrete research, 32(4) (2002) 529-556.

[28] J. Planas, M. Elices, G.V. Guinea, Measurement of the fracture energy using three-point bend tests: Part 2—Influence of bulk energy dissipation. Materials and Structures, 25(5) (1992 305-312.

[29] M. D'ESSAI, M. É. T. H. O. D. E. S., & DE LA RILEM, P. D. R. (1990). Size-effect method for determining fracture energy and process zone size of concrete. Materials           and Structures, 1(1), 7.

[30] S. Khalilpour, E. BaniAsad, M. Dehestani, A review on concrete fracture energy and effective parameters. Cement and Concrete research, 120 (2019) 294-321.

[31] A. Hillerborg, M. Modéer, P.E. Petersson, Analysis of crack formation and crack growth in concrete by means of fracture mechanics and finite elements. Cement and                   concrete research, 6(6) (1976) 773-781.

[32] Bazant, Z. P., & Kazemi, M. T. (1990). Determination of fracture energy, process zone longth and brittleness number from size effect, with application to rock and                      concrete. International Journal of fracture, 44(2), 111-131. [33] CEB-FIP

[33] Ceb-Fip. CEB-FIP model code 1990 1990:460. doi:10.1680/ceb-fipmc1990.35430.

[34] Bažant, Z. P., & Becq-Giraudon, E. (2002). Statistical prediction of fracture parameters of concrete and implications for choice of testing standard. Cement and concrete research, 32(4), 529-556.

[35] Japan Society of Civil Engineers. STANDARD SPECIFICATIONS FOR CONCRETE STRUCTURES 2007 ‘‘Design”. 2007; 15:1–503.

[36] CEB –FIP, Model Code -Final draft: Volume 1. Vol. 65. fib Fédération internationale du béton, 2012. Cent Siegmar Kästl eK, Ger 2010.

[37] ASTM C33. (2003). ASTM C33 standard specifications for concrete aggregates. ASTM Standard Book.

[38] Standard, A. S. T. M. (2010). Standard test method for compressive strength of cylindrical concrete specimens. ASTM C39.

[39] ASTM C496. (2004). Standard test method for splitting tensile strength of cylindrical concrete specimens. Annual Book of ASTM Standards.

[40] Standard, A. S. T. M. (2014). ASTM C567, Standard Test Method for Determining Density of Structural Lightweight Concrete. ASTM Int.

[41] ASTM Standard C469/C469M-14 (2014) Standard Test Method for Static Modulus of Elasticity and Poisson’s Ratio of Concrete in Compression. Annual Book of ASTM Standards, Vol. 09.49, ASTM International, West Conshohocken.

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