scholarly journals Effect Of Resilient Modulus on Permanent Deformations Using VESYS 5W Program

2022 ◽  
Vol 961 (1) ◽  
pp. 012007
Author(s):  
Hasan H Joni ◽  
Yassir K Hadi
Keyword(s):  
Surface Layer ◽  
High Temperatures ◽  
Resilient Modulus ◽  
Base Layer ◽  
Asphalt Mixes ◽  
Potential Value ◽  
Traffic Loads ◽  
Pavement Layers

Abstract Due to high temperatures and increased traffic loads, most of Iraq’s streets suffer from permanent distortion problems, especially in streets where there are checkpoints, therefore, there are needs for reports and researches specialized in improving the pavement layers and increasing their resistance to temperatures and high traffic loads to reduce the rut depth. In this research, the VESYS 5W program was used to find a potential value for rut depth, where ordinary asphalt mixes and improved asphalt mixes were used using SBS polymer at 4% by weight of asphalt were it is evaluated according to different properties of these mixture and the resilient modulus one of these properties for it is importance. The results showed that when the value of the resilient modulus increases, the rut depth decreases, as the rut depth was reduced by 42.5% for the surface layer and 73% for the base layer

Integrating the Dynamic Modulus of Asphalt Mixes in the 1993 AASHTO Design Method

2017 ◽  
Vol 2640 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Yara S. Hamdar ◽  
Ghassan R. Chehab
Keyword(s):  
Dynamic Modulus ◽  
Resilient Modulus ◽  
Design Method ◽  
Asphalt Mixture ◽  
Base Layer ◽  
Asphalt Mixes ◽  
Design Guide ◽  
Abstract Measure ◽  
Pavement Structures ◽  
Structural Coefficient

The AASHTO Guide for Design of Pavement Structures 1993 (1993 Design Guide) remains the most widely used pavement design manual by highway agencies and design consultants around the world. As defined in the 1993 Design Guide, the structural coefficient of a pavement layer ( ai) is an abstract measure of the relative ability of a unit thickness of a given material to function as a structural component of the pavement. Nevertheless, the assumed ai values of the asphalt layers and a proposed relationship between ai and the resilient modulus do not account for the mechanical and physical properties of asphalt materials, traffic volume and speed, layer thicknesses (thin versus thick pavements), climate, and unbound layer properties. The purpose of this research was to enhance the design methodology incorporated in the 1993 Design Guide by integrating asphalt mixture properties in the design process. The objective was to devise a relationship between the structural coefficient ( ai) of the asphalt layer and the effective dynamic modulus (|E*|eff.) of the corresponding asphalt mix to yield a more realistic estimate of the structural capacity of the asphalt layer. The paper illustrates the development of a multilinear relationship between ai, (|E*|eff.), and the resilient modulus of the aggregate base layer. Pavement structural designs for various asphalt mixes and design inputs using the developed ai–(|E*|eff.) relationship yielded asphalt layer thicknesses that were generally smaller than those obtained using the typical ai value of 0.44 for the asphalt layer and closer to thicknesses obtained with the AASHTO mechanistic–empirical design method using the Pavement ME software.

Consideration of the Cross-Anisotropy of Different Materials of the Asphalt Surface Layer and Temperature to Determine Pavement Responses

2021 ◽  
Vol 13 (1) ◽  
pp. 140-151
Author(s):  
Minrui Guo ◽  
Xinglin Zhou
Keyword(s):  
Surface Layer ◽  
High Temperatures ◽  
Low Temperatures ◽  
Compressive Strain ◽  
Fatigue Cracking ◽  
Element Model ◽  
Rate Of Change ◽  
Temperature Relationship ◽  
The Cross ◽  
Cross Anisotropy

The effects of the cross-anisotropy of different materials of the asphalt surface layer and the depth-temperature relationship on pavement responses and damage are investigated. A three-dimensional Finite-Element Model (FEM) of the pavement, which considers the depth-temperature relationship of the surface layer under moving tire load, is developed. Pavement damage models are established to evaluate the damage ratio for primary rutting and fatigue cracking. The results show that the compressive strain at the bottom of the surface layer increases as the temperature increases, and the cross-anisotropy (n-value) decreases, indicating that a decrease in the horizontal modulus of different materials of the surface layer increases the damage ratio for primary rutting at high temperatures. The tensile strain at the bottom of the surface layer declines as the n-value increases to 1. For the same change in the n-value, the rate of change of the damage ratio for fatigue cracking is greater at low temperatures than at high temperatures, demonstrating that the number of allowable load repetitions is more sensitive at low temperatures. In addition, the effect of cross-anisotropy and temperature on the vertical stress are larger on the top of the base than in the subbase and subgrade.

scholarly journals Performance Evaluation of Hot Mix Asphalt with Different Proportions of RAP Content

2018 ◽  
Vol 34 ◽  
pp. 01026
Author(s):  
Ahmad Kamil Arshad ◽  
Haryati Awang ◽  
Ekarizan Shaffie ◽  
Wardati Hashim ◽  
Zanariah Abd Rahman
Keyword(s):  
Hot Mix Asphalt ◽  
Resilient Modulus ◽  
Design Method ◽  
Asphalt Pavement ◽  
Cost Savings ◽  
Volumetric Analysis ◽  
Public Works ◽  
Asphalt Binders ◽  
Moisture Susceptibility ◽  
Asphalt Mixes

Reclaimed Asphalt Pavement (RAP) is old asphalt pavement that has been removed from a road by milling or full depth removal. The use of RAP in hot mix asphalt (HMA) eliminates the need to dispose old asphalt pavements and conserves asphalt binders and aggregates, resulting in significant cost savings and benefits to society. This paper presents a study on HMA with different RAP proportions carried out to evaluate the volumetric properties and performance of asphalt mixes containing different proportions of RAP. Marshall Mix Design Method was used to produce control mix (0% RAP) and asphalt mixes containing 15% RAP, 25% RAP and 35% RAP in accordance with Specifications for Road Works of Public Works Department, Malaysia for AC14 dense graded asphalt gradation. Volumetric analysis was performed to ensure that the result is compliance with specification requirements. The resilient modulus test was performed to measure the stiffness of the mixes while the Modified Lottman test was conducted to evaluate the moisture susceptibility of these mixes. The Hamburg wheel tracking test was used to evaluate the rutting performance of these mixes. The results obtained showed that there were no substantial difference in Marshall Properties, moisture susceptibility, resilient modulus and rutting resistance between asphalt mixes with RAP and the control mix. The test results indicated that recycled mixes performed as good as the performance of conventional HMA in terms of moisture susceptibility and resilient modulus. It is recommended that further research be carried out for asphalt mixes containing more than 35% RAP material.

scholarly journals Utilization of copper fiber waste to increase compressive strength and split tensile strength of rigid pavement

2021 ◽  
Vol 878 (1) ◽  
pp. 012052
Author(s):  
H Ndruru ◽  
R M Simanjuntak ◽  
S P Tampubolon
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Surface Layer ◽  
Concrete Slab ◽  
Residential Areas ◽  
Split Tensile Strength ◽  
Rigid Pavement ◽  
Traffic Loads ◽  
Pavement Construction ◽  
Low Traffic

Abstract The rigid pavement is a pavement construction in which a concrete slab is used as the top layer, which is located above the foundation or directly above the subgrade, without or with an asphalt surface layer. One type of rigid pavement used in Indonesia is rigid pavement without using reinforcement which is usually used in areas with low traffic or residential areas. Pavement without using reinforcement is the small split tensile strength so that the part of the plate will experience cracks due to stresses that cannot be avoided from traffic loads. Therefore, it is necessary to have reinforcement on the concrete slab so that the cracks do not extend. In this research, the use of copper fiber waste from electronic cables as a substitute solution for reinforcement to be used as a mixture in concrete. The experiments were carried out using fiber with variations of 0%, 0.5%, 1%, and 1.5% of the total weight of concrete mixture material and then tested at 28 days of concrete age. This research showed the variation of fiber weight until 1,5% increase the split tensile strength up to 32,46% and the compressive strength up to 9,16%.

Effect of Coarse Aggregate Morphology on the Resilient Modulus of Hot-Mix Asphalt

2005 ◽  
Vol 1929 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Tongyan Pan ◽  
Erol Tutumluer ◽  
Samuel H. Carpenter
Keyword(s):  
Surface Texture ◽  
Coarse Aggregate ◽  
Resilient Modulus ◽  
Asphalt Binder ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
Asphalt Mixes ◽  
Aggregate Morphology ◽  
The Relationship

The resilient modulus measured in the indirect tensile mode according to ASTM D 4123 reflects effectively the elastic properties of asphalt mixtures under repeated load. The coarse aggregate morphology quantified by angularity and surface texture properties affects resilient modulus of asphalt mixes; however, the relationship is not yet well understood because of the lack of quantitative measurement of coarse aggregate morphology. This paper presents findings of a laboratory study aimed at investigating the effects of the material properties of the major component on the resilient modulus of asphalt mixes, with the coarse aggregate morphology considered as the principal factor. With modulus tests performed at a temperature of 25°C, using coarse aggregates with more irregular morphologies substantially improved the resilient modulus of asphalt mixtures. An imaging-based angularity index was found to be more closely related to the resilient modulus than an imaging-based surface texture index, as indicated by a higher value of the correlation coefficient. The stiffness of the asphalt binder also had a strong influence on modulus. When the resilient modulus data were grouped on the basis of binder stiffnesses, the agreement between the coarse aggregate morphology and the resilient modulus was significantly improved in each group. Although the changes in aggregate gradation did not significantly affect the relationship between the coarse aggregate morphology and the resilient modulus, decreasing the nominal maximum aggregate size from 19 mm to 9.5 mm indicated an increasing positive influence of aggregate morphology on the resilient modulus of asphalt mixes.

scholarly journals Analysis of Loading Stress of Pavement Structure using One-Step Forming Cement-Stabilized Macadam Base

2019 ◽  
Vol 136 ◽  
pp. 04042
Author(s):  
Yue Qin ◽  
Yongjun Meng ◽  
Zubiao Lu ◽  
Qixiong Zhao ◽  
Hongliu Rong
Keyword(s):  
Surface Layer ◽  
Working Conditions ◽  
Maximum Shear Stress ◽  
Thin Layers ◽  
Base Layer ◽  
Pavement Performance ◽  
Principal Stresses ◽  
Large Thickness ◽  
One Step ◽  
Pavement Structure

Layered construction of large thickness cement-stabilized macadam base makes the base change from designed being forced by whole layer to being forced by two thin layers, the existence of interfacial friction between two thin layers reduces the pavement performance of the base, which finally cause the reduction of pavement performance of whole pavement structure. To analyze the load responses of large thickness cement-stabilized macadam base asphalt pavement under different working conditions, pavement surface deflection, maximum principal stresses of surface layer bottom and base layer bottom, minimum principal strain of soil base top and maximum shear stress of surface layer bottom under two different working conditions(layered construction and one-step forming) are taken as indexes and are obtained by finite element analysis method in this paper.

scholarly journals Finite Element Analysis of Geogrid-Stabilized Unpaved Roads

2020 ◽  
Vol 12 (5) ◽  
pp. 1929
Author(s):  
Giovanni Leonardi ◽  
Dario Lo Bosco ◽  
Rocco Palamara ◽  
Federica Suraci
Keyword(s):  
Finite Element ◽  
Fem Analysis ◽  
Base Layer ◽  
Element Analysis ◽  
Unpaved Roads ◽  
Unpaved Road ◽  
Traffic Loads ◽  
Granular Fill ◽  
Wheel Loading ◽  
Granular Base

The need to increase the durability of unpaved roads and the need to improve driver comfort have led to this research: to focus more attention on the use of reinforcements for this type of road. Unpaved roads are created by using an unbound granular base layer placed on compacted cohesive soils. When the subgrade is weak, due to its poor consistency and high compressibility, generally, a geosynthetic reinforcement (geogrid and/or geotextile) is placed over the subgrade, followed by a compacted granular fill layer. The use of geosynthetics can produce several benefits, such as draining, reinforcement, filtering, separation, and proofing. This paper aims to present a numerical investigation using 3-D Finite Element Modeling (FEM) to analyze the improvement, in terms of the rutting reduction of an unpaved road system, reinforced by a geogrid, under repeated traffic loads. 3-D FEM analysis was carried out on two unpaved road sections, one reinforced and the other unreinforced, with both subjected to an impulsive wheel loading. It can be concluded that a significant improvement in pavement behavior is obtained by placing a geogrid layer at the base–subgrade interface. In fact, the obtained results show that geogrid reinforcement can provide a relevant contribution to the reduction of permanent deformations.

Variations in Measured Resilient Modulus of Asphalt Mixes

1992 ◽  
Vol 4 (4) ◽  
pp. 343-352 ◽  
Author(s):  
Faisal H. Al‐Sugair ◽  
Jamal A. Almudaiheem
Keyword(s):  
Resilient Modulus ◽  
Asphalt Mixes

scholarly journals Laboratory characterization of reclaimed asphalt pavement for road construction in Egypt

2017 ◽  
Vol 44 (6) ◽  
pp. 417-425 ◽  
Author(s):  
E. Mousa ◽  
A. Azam ◽  
M. El-Shabrawy ◽  
S.M. El-Badawy
Keyword(s):  
Resilient Modulus ◽  
Asphalt Pavement ◽  
Road Construction ◽  
California Bearing Ratio ◽  
Base Layer ◽  
Coefficient Of Determination ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Load Duration ◽  
The Impact

This paper presents the engineering characteristics of reclaimed asphalt pavement (RAP), blended with virgin aggregate for unbound base and subbase layers. The proportions of RAP were 0%, 20%, 60%, 80%, and 100% by total mass of the blend. The experimental laboratory testing included index properties such as gradation, modified Proctor compaction, California Bearing Ratio, and hydraulic conductivity. Repeated load resilient modulus testing was conducted on the blends. The impact of load duration on resilient modulus was also investigated. A strong inverse trend was found between resilient modulus and California Bearing Ratio. An accurate model was proposed for the prediction of the resilient modulus as a function of stress state and reclaimed asphalt pavement percentage with coefficient of determination of 0.94. Finally, multilayer elastic analysis of typical pavement sections with the base layer constructed of virgin aggregate and reclaimed asphalt pavement blends showed good performance.

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