The effect of fines content on force transmission and fabric development gap-graded mixtures under triaxial compression has been studied using the discrete-element method. Results were used to define load-bearing soil fabrics where relative contributions coarse fine components are explicitly quantified in terms transmission. Comparison with previous findings suggests that lower particle size ratios result higher interaction between components. A potential for instability was detected...

During asphalt mixture compaction, loads in the material are mainly transferred through contact between stones and interaction binder. The behaviour of such materials is suitable to model using Discrete Element Method (DEM). In this study, a new DEM modelling approach has been developed for studying compaction process, incorporating damage laws based on granular mechanics. simulations, aggregate fracture handled by recently method particle DEM, previously performed experiments granite...

Asphalt concrete (AC) exhibits significant tension–compression (TC) asymmetry and aggregate contacts can be one of the critical contributors to this behavior. Nevertheless, underlying mechanisms are still unclear, there has been no study quantify To fill research gap, multiscale characterization modeling on AC were performed in study. At microscale level, nanoindentation tests conducted characterize contact characteristics region (CR). The CR was found have a sandwich-like structure...

Permanent deformation of unbound granular materials plays an essential role in the long-term performance a pavement structure. Stability is defined by particle-to-particle contact system, particle size distribution and packing arrangement. This paper presents gradation model based on theory to evaluate permanent materials. The framework was evaluated using 10 from different countries. disruption potential, which determines ability secondary structure (SS) disrupt primary (PS), introduced....

In the present paper a robust and general computational framework that captures dynamic response of flexible pavements to moving vehicle is presented. A finite element method relied upon in order establish function for linear viscoelastic pavement structure with effects taken into account. characterise loads induced on by traffic, quarter car model combined measured road profiles used. Once both traffic functions are known, stresses strains can be obtained frequency–wavenumber domain through...

Over the past several decades, California bearing ratio (CBR) value has been used in many countries for empirical pavement designs and still are using it unbound granular materials strength measurement as input to their design chart. Furthermore, CBR of material is frequently correlated with its fundamental mechanical properties such resilient modulus, which turn often an a mechanistic procedure. In present study, effect aggregate packing on values investigated. A theory-based framework that...

Asphalt concrete (AC) is a composite material consisting of binder, aggregates and air voids. The quantitative effect aggregate-to-aggregate contact on the mechanical performance AC an important complex issue, which has not been fully understood yet. To fill this gap, study aims to characterize aggregate contacts in evaluate their effects viscoelastic behavior through micromechanical finite element (FE) modeling. end, 3D microstructural models were generated digital image processing (DIP)...

Interlayers in asphalt pavements are potential structural damage initiators. In order to better understand the quantitative role of interlayer parameters, such as surface roughness, binder type, content and loading type on shear strength, this paper focuses effects particle interlock contact conditions strength through experimental numerical modelling. Experimentally, box tests a model material consisting stiff blended with steel balls performed without normal force confinement. A Discrete...

Asphalt concrete (AC) exhibits significant tension-compression (TC) asymmetry, which is currently not considered in pavement design. This study develops a novel temperature-dependent dual viscoelastic model to quantitatively capture the behaviour of AC. Unlike conventional constitutive model, proposed decomposes strain into tensile and compressive components characterise AC's TC asymmetry. Additionally, systematic modelling framework with intrinsic asymmetry developed for first time predict...

Enhancing the quality of granular layers is fundamental to optimise structural performance pavements. The objective this study investigate whether previously developed packing theory-based aggregate parameters can evaluate resilient modulus unbound materials. In study, 19 differently graded materials from two countries (USA and Sweden) were evaluated. This validated both porosity primary structure (PS) contact points per particle (coordination number) as key for evaluating showed that...

In this paper, a new mechanics-based top-down fatigue cracking analysis framework is presented for asphalt pavements. A mixture morphology-based set of material sub-models characterising key properties and their change over time. Predicting the load induced crack initiation (CI) time by utilising comprehensive creates possibility optimising morphology while taking into account its subsequent effect on long-term pavement performance. The was calibrated subsequently validated against number...

A new micromechanical model for predicting viscoelastic properties of mastic is proposed and validated with experiments. The developed based on the finite element method allows by means fundamental mechanical geometrical its constituents. influence modelling parameters model's accuracy evaluated optimal parameter combinations are identified. It shown that can capture measured behaviour mastics range loading, temperature material examined. Accordingly, it may be a useful tool optimizing...