An attempt is made to connect the link between internal chemical and molecular mechanical property change external physical, rheological for asphalt before after oxidative aging using dynamics (MD) simulation. Intermolecular interactions, density, bulk modulus zero shear viscosity changes of model systems under different compressive tensile stress rates are investigated at room temperature (298 K). Simulation results demonstrate that oxidised functional groups in molecules increase strength...

The moisture damage in polymer modified asphalts has been studied for decades, yet the effects of chemical functional groups on sensitivity are not known. In this study, a nanoscale experiment is conducted to measure these terms adhesive/cohesive forces using an atomic force microscopy (AFM). A base asphalt binder and two polymers such as styrene-butadiene (SB) styrene-butadiene-styrene (SBS) used prepare AFM sample glass substrates. samples conditioned under dry wet conditions. AFM, probed...

Nanoindentation is a relatively new technique which has been used to measure nanomechanical properties of surface layers bulk materials and thin films. In this study, micromechanical such as hardness Young's modulus asphalt binders concrete are determined by nanoindentation experiments. Indentation tests conducted on base binder two polymer-modified performance grade (PG) PG-70-22 PG76-28. addition, Superpave mixes SP-B SP-III designed using these PG binders, the corresponding compacted...

In this study, a four-layer feed-forward neural network is constructed and applied to determine mapping associating mix design testing factors of asphalt concrete samples with their performance in conductance flow or permeability. To generate data for the model, total 100 field cores from 50 different mixes (two replicate per mix) are tested laboratory permeability volumetric properties. The significant that affect identified using simple multiple regression analysis. analyses results show...

In this study, a molecular dynamic (MD) simulation is employed to determine the thermodynamic properties of asphalt binder components, namely, asphaltene and resin, before after oxidative aging. For aging asphaltenes, percentage oxygen considered in MD simulations 0.1, 1, 12, 23, 46.5% asphaltenes. resins, used 5, 15, 25% resins. Using few oxygen, asphaltene, resin molecules as input, are run on system at fixed number pressure predict internal energy, structure, density function temperature....

Limiting the presence of water inside an asphalt concrete (AC) pavement can slow down process involved in diffusion, hydration, adhesion loss, and other mechanisms moisture damage. In past, numerous studies have been conducted on topic damage permeability, but very few related permeability with AC. This study evaluates whether such relation exists. essence, a field survey is to identify set pavements (bad) that suffer from (good) do not exhibit Field tests coring are pavements. Laboratory...

In a nanoindentation test, test sample is indented or loaded by an intender tip and then unloaded, the load-displacement data are recorded. Load-displacement analyzed using common method to determine elastic modulus hardness of materials. The slope unloading curve positive typically follows loading for hard samples such as aluminum silicon. analysis not applicable if negative slope, which case soft viscous materials, asphalt binders polymers. However, past studies have attempted examine...

Objective: Teenage drivers are more likely to be involved in severely incapacitating and fatal crashes compared adult drivers. Moreover, because two thirds of urban vehicle miles traveled on signal-controlled roadways, significant research efforts needed investigate intersection-related teenage driver injury severities their contributing factors terms behavior, vehicle–infrastructure interactions, environmental characteristics, roadway geometric features, traffic compositions. Therefore,...

Polymers are commonly used to modify asphalt binder in order satisfy the performance-grade binder’s rheological properties, such as shear, storage, loss, and bending stiffness. However, it is not known what types percentages of polymers affect these properties under conditions aging. To this end, base binders were modified with styrene-butadiene styrene-butadiene-styrene at 3, 4, 5% then aged laboratory using a rolling thin film oven for short-term aging, pressure aging vessel long-term...

This study evaluates the pore structure of asphalt concrete (AC) samples by measuring different components space and their contributions to permeability moisture damage. Three total namely permeable, dead-end isolated pores are quantified using tracer test, which is a combination permeameter salt concentration meter. Permeable become impermeable if an AC sample compacted below 5% air voids. increase with in radius. It observed from this that permeable has good correlation permeability,...

Asphalt concrete (AC) consists of coarse aggregate, asphalt binder, and fines. The binder creates an film around the aggregate Fines are trapped inside film, which is also known as mastic. Mastic govern most mechanical properties AC. Therefore, researchers have performed various tests on mastic to understand macroscale behavior Nanomechanical characterization more appropriate for mastic, thinness approximately 15–20 μm particle. For this paper, authors conducted nanoindentation integral...

The research reported in this paper investigates the coefficient of thermal contraction (CTE) and expansion asphalt concrete (AC) under different conditions laboratory. As a first step, CTC CTE AC at temperatures ranging between −20 55°C were measured using field samples to examine temperature effect. Then, difference values vertical horizontal directions (cross anisotropy) evaluated samples. influences air void (AV), aggregate type, gradation on also investigated laboratory prepared...

This study evaluates the effects of moisture conditioning on changes in chemical composition and mechanical properties asphalt binder. Moisture is conducted using AASHTO T 283 procedure recently developed moisture-induced sensitivity testing (MIST) device. Chemical analysis performed Fourier transform infrared device by a dynamic shear rheometer. Results show that ageing as well other occurred during conditioning. Changes binder fatigue life damaged modulus are observed. Undamaged cohesive...