Fracture toughness prediction using Weibull statistical method for asphalt mixtures containing different air void contents

Abstract

Brittle fracture of asphalt mixtures at low temperatures is one of the main deterioration modes of pavements. Hence as an important design parameter, it is required that a reliable value for fracture toughness of asphalt mixtures is known. However, because of natural inhomogeneity of asphalt mixtures and inherent sources of scatters such as random distribution of ingredients and preparation process, the use of statistical analyses might provide better estimations for the crack growth resistance of asphalt mixtures. In this paper by conducting several low temperature fracture toughness experiments on three types of asphalt mixtures with different air void contents, the effects of air void percentage on mode I fracture toughness are studied statistically. Fifty six edge cracked semi‐circular bend specimens containing 4, 5 and 7% air voids were tested, and the corresponding two and three‐Weibull distribution parameters were determined for each set of data. It was shown that the Weibull model can be used successfully for predicting the statistical nature of tensile cracking phenomenon in asphalt mixtures. The mean fracture toughness values and the Weibull parameters were reduced by increasing the air void content. Furthermore, the distribution parameters obtained experimentally for the mixtures containing 4% and 5% voids were also predicted quite well in terms of the Weibull parameters of a reference mixture containing 7% air void.

Evaluation of interfacial bond strength between Portland cement concrete and asphalt concrete layers using bi-material SCB test specimen

“…The specimen has been frequently used in the past but only for the simple case of homogeneous material (single material) in order to obtain fracture toughness for several engineering materials including, rocks, concrete, asphalt, polymers, etc. (Ayatollahi et al, 2006;Lim et al, 1994;Li & Marasteanu, 2005, Aliha & Fattahi Amirdehi 2017,2015b, Aliha & Ayatollahi 2013. In order to evaluate tensile/ shear bond strength between the PCC and AC using interfacial fracture mechanics concepts, it is necessary to define the state of mode mixity by calculating the mode I and mode II stress intensity factors (KI and KII) for different loading positions and crack lengths.…”

Numerical evaluation of mode I/II SIF of quasi-brittle materials using cracked semi-circular bend specimen

“…The SCB specimen has a simple geometry, loading arrangement, the capability of applying various mode mixity by changing the pre-crack inclination angle relative to the applied load Chong & Kuruppu, 1984;Kuruppu & Chong, 2012;Rashidi Moghaddam et al, 2017). It provides a simple and effective technique for conducting mixed mode fracture tests in brittle materials (Aliha et al, 2010Elghazel et al, 2016;Ameri et al, 2012Ameri et al, , 2016Fathipour Azar et al, 2015;Kataoka et al, 2017;Wei et al, 2016Aliha & Ayatollahi, 2013Aliha & Saghafi, 2013;Aliha & Fattahi Amirdehi, 2017;Fakhri et al, 2018;Roy et al, 2017a,b;Abd-Elhady 2013;Mirsayar et al, 2017;Funatsu et al, 2014;Artamendi & Khalid, 2006). Nevertheless, the crack properties such as location, size, inclination and loading configuration have a pronounced effect on the crack extension.…”

Tangential strain‐based criteria for mixed‐mode I/II fracture toughness of cement concrete

“…This paper examines the fracture resistance of concrete focusing on the strain‐based criteria, using edge cracked semicircular bend (SCB) specimens. The SCB specimen has been widely used for mixed‐mode fracture analysis of different engineering materials such as poly(methyl methacrylate), rock, concrete, and asphalt concrete . The mixed‐mode I/II stress intensity factors as well as the first nonsingular tangential strain term around the crack tip are calculated by using the numerical simulation for the SCB specimens.…”