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A fundamental multiple-stage ANN-based sensitivity analysis to predict the dynamic modulus of hot mix asphalt considering the effect of confining stress

Ali Heidaripanah, Abolfazl Hassani
Journal PapersMaterials and Structures , Volume 54 , Issue 1, 2021 February , {Pages 15-Jan }

Abstract

Dynamic modulus| E*|, of Hot Mix Asphalt (HMA) is a crucial parameter in the pavement design and analysis. The Witczak regression-based model adopted by the Mechanistic-Empirical Pavement Design Guide (MEPDG) could be considered as the most fundamental and widely used model to estimate the dynamic modulus of HMA. However, the effect of confining stress has not been considered in this model as an effective parameter. In this paper, attempts were undertaken to develop a new predicting model for| E*| of HMA considering the effect of confining stress. Artificial Neural Networks (ANNs) was administrated as the computational tool for this modeling using 1320| E*| test results performed at the University of Maryland. Asphalt mix parameters, test f

Evaluation of the Effect of Macro-Synthetic Fibers on Thickness and Cost Index of Jointed Concrete Pavements Considering the Impact of Post-Cracking Flexural Strength

Abolfazl Hassani, Seyed Javad Vaziri Kang Oleyaei, Mohammad Reza Hajizadeh
Journal PapersAmirkabir Journal of Civil Engineering , 2021 January 6, {Pages }

Abstract

Considering the effect of post-cracking strength and the cost of pavement construction in designing the thickness of jointed concrete pavements lead to more effective and economical pavement design. Therefore, this study evaluates the effect of the addition of macro-synthetic fibers on the thickness and construction cost of jointed concrete pavements, considering the impact of post-cracking flexural strength. The effect of polypropylene macro fibers in the amounts of 0, 1, 2, and 3 kg/m3 on changes of thickness and construction cost index of jointed concrete pavements was studied considering the modulus of rupture and equivalent flexural strength ratio of each mix design in pavement thickness design. It was observed that the addition of mac

The Influence of Aggregate Gradation Curve on Predicting the Indirect Tensile Strength of HMA Mixtures Using Soft Computing Approach

Ali Heidaripanah, Abolfazl Hassani, Maziar Moaveni
Journal Papers , Issue TRBAM-21-04158, 2021 January , {Pages }

Abstract

Indirect Tensile Strength (ITS) of HMA mixtures is a fundamental parameter in pavement design and evaluating the pavement distresses. Researchers have proposed some predictive models to estimate the ITS of asphalt mixtures. However, the impact of aggregate size distribution has not been directly considered in those models. In this research, attempts were undertaken to develop a new predictive model for ITS of HMA mixtures considering the effect of aggregate gradation curve. Artificial Neural Networks (ANN) was used as the computational tool using 259 ITS test results from LTPP database in which Indirect Tensile Tests (IDT) have been conducted according to AASHTO T-322 standard. The new ANN model could successfully predict the ITS of HMA wit

Failure behavior of functionally graded roller compacted concrete pavement under mode I and III fracture

M Ahmadi, GA Shafabakhsh, P Di Mascio, A Hassani
Journal Papers , , {Pages }

Abstract

Development of procedure for design and preparation of open-graded asphalt mixture used in semi-flexible pavement

M Taghipoor, A Hassani, MM Karimi
Journal Papers , , {Pages }

Abstract

Adaptive Neuro-Fuzzy Inference System to Predict the Dynamic Modulus of Hot Mix Asphalt

A Heidaripanah, A Hassani
Journal Papers , , {Pages }

Abstract

Effect of bacteria on self-healing of bio-concrete by increasing compressive strength

A Noori Shahrabadi, A Hassani, B Bakhshi
Journal Papers , , {Pages }

Abstract

An Investigation of the Relationship among Skid Resistance, Mean Texture Depth and Abrasion Resistance for Different Macrotextures of Concrete Pavements

R Jalalkamali, MM Dibaee, MH Jalal Kamali, A Hassani
Journal Papers , , {Pages }

Abstract

Laboratory Evaluation of Alkali-Activated Slag Concrete Pavement Containing Silica fume and Carbon Nanotubes

AM Janaki, G Shafabakhsh, A Hassani
Journal Papers , , {Pages }

Abstract

A state of the art of semi-flexible pavements: Introduction, design, and performance

Abolfazl Hassani, Mohammad Taghipoor, Mohammad M Karimi
Journal Papers , Volume 253 , 2020 August 30, {Pages 119196 }

Abstract

Semi-flexible pavement (SFP) is a new pavement technology consisting of open-graded asphalt concrete with a high air void content filled by injecting special grouting materials. The SFP is constructed without expansion, contraction, and construction joints and also demonstrates prominent rutting and shoving/corrugation resistances. These new pavement materials simultaneously possess flexible characteristics of asphalt pavements and the high strength (hardness) of concrete pavements. The main purpose of this study is to provide comprehensive review on design, construction, and performance of semi-flexible pavements based on laboratory and field scales evaluation. The first part of this paper presents the introduction of semi-flexible pavemen

Fracture and mechanical performance of Two-Lift Concrete Pavements made of Roller Compacted Concrete and Polypropylene Fibers

Mohsen Ahmadi, Gholam Ali Shafabakhsh, Abolfazl Hassani
Journal PapersConstruction and Building Materials , 2020 October 26, {Pages 121144 }

Abstract

The present study has examined the two-lift concrete pavement (2LCP) fracture and mechanical behavior by casting the Roller Compacted Concrete (RCC) as the bottom lift and the conventional or fibrous Portland cement concrete (PCC, FPCC) as the top lift. To this end, the three-point bending test was carried out on notched beams by considering different thicknesses for both layers. Results showed that fibers had no positive effects on the compressive and flexural strength, but improved the post cracking behavior considerably. Compared to full-depth RCC/PCC, 2LCP specimens had similar flexural strengths, but an increase in the FPCC top-layer thickness increased the fracture energy noticeably.

Presenting an experimental model to investigate the effect of changing the dimensions of macro-synthetic-fiber-reinforced concrete on fracture energy

Abolfazl Hassani, Mohammad Daneshfar
Journal PapersJournal of Structural and Construction Engineering , Volume 7 , Issue 1, 2020 March 20, {Pages 72-87 }

Abstract

Concrete has a brittle behavior as one of the most frequently used construction materials. Adding fibers to concrete can enhance its ductility and some of its mechanical properties. For this purpose, a laboratory study was conducted in order to present an experimental model to investigate the effect of size of micro-synthetic-fiber-reinforced concrete on fracture energy changes. In this study, concrete beam specimens were manufactured and evaluated with three different thicknesses and widths. Results indicated that by increasing the thickness of the specimens, fracture energy was respectively increased by 15.3-63.1%. Moreover, by increasing the width of the specimen, fracture energy was respectively increased by 42.04-50.72 %.Fiber-reinforc

Evaluation of Recycled Plastic (PET) Effects on Mechanical Properties and Abrasion Resistance of Concrete Pavements

Bashir Moradi, Abolfazl Hassani, Hamed Rooholamini
Journal PapersJournal of Transportation Research , 2020 May 2, {Pages }

Abstract

The vulnerability of non-biodegradable wastes and their exploiting to reduce contamination of environment has been abundantly attracted the engineers’ attention. In addition, the abrasion resistance of concrete pavement is one of the prominent factors of durability causing non-affordable maintenance and rehabilitation costs. Thus, utilizing plastic wastes either as aggregate replacement or fiber is considered as an eco-friendly idea. Recently, numerous studies have been carried out to investigate the effects of PET (with different shapes and sizes) on mechanical properties and durability characteristics of concrete. In the present research, 5%, 10%, 15%, 20%, 25% and 30% by volume fraction of natural river sand in concrete mixes were repl

The Influence of Moisture content and Compaction level on LWD Modulus of Unbound Granular Base Layers

A Kavussi, M Qorbaninik, A Hassani
Journal PapersTransportation Geotechnics , 2019 June 13, {Pages 100252 }

Abstract

Resilient behavior of Unbound Granular Material (UGM), as defined with stiffness modulus, is considered to be one of the major parameters in pavement analysis. This itself is affected by several other factors.In this research, the effects of compaction level, moisture content and stress state were investigated on UGM resilient behavior using a Light Weight Deflectometer (LWD). For each of these parameters, three levels were selected. Response Surface Method (RSM) was applied and based on the results 17 test designs were determined.The results showed good correlation between stiffness modulus and compaction level, moisture content, compaction-moisture interaction and stress state (drop weight of LWD in this research) at 90% significant level

Investigating the Relation among British Pendulum Number, Mean Texture Depth and Asphalt Content in Hot Mix Asphalt

Jalal Kamali, Mohammad Hossain, Abolfazl Hassani, Javad Sodagari
Journal PapersJournal of Rehabilitation in Civil Engineering , 2019 June 10, {Pages }

Abstract

Pavement surface texture and its skid resistance are two key safety parameters of highways, which both are influenced by pavement characteristics. This research is done on a newly constructed asphalt pavement (Qom-Garmsar freeway) in Iran. The goal is investigating the relation between skid resistance and pavement texture in order to asphalt content changes in Hot Mix Asphalt. Mean Texture Depth (MTD) and British Pendulum Number (BPN) are being used to quantify pavement texture and skid resistance, respectively. The results show that the asphalt content has a significant effect on MTD and consequently, BPN in loaded pavements, as well as non-loaded pavements. The result showed that the lowest BPN value obtained when the asphalt content is a

Mechanical and fracture properties of concrete containing treated and untreated recycled concrete aggregates

F Kazemian, H Rooholamini, A Hassani
Journal PapersConstruction and Building Materials , Volume 209 , 2019 June 10, {Pages 690-700 }

Abstract

This paper presents the results of an experimental research into concrete produced by replacing the natural aggregates with treated and untreated coarse Recycled Concrete Aggregates (RCA). The compressive and flexural strength as well as fracture energy tests were carried out. In order to determine the efficiency of treated and untreated RCA on fracture properties of concrete, single edge notched beam, semi-circular bend, and edge notched disc bend geometries were employed. The results indicated that although Treated Recycled Concrete Aggregates (TRCA) might push to more effort in production process, there are significant benefits in using TRCA in concrete mixtures. Denser microstructure and stronger interfacial transition zone in TRCA enha

the effect of specimen size on Flexural Fatigue Life of macro-synthetic-fiber-reinforced concretes

Abolfazl Hassani
Journal PapersModares Civil Engineering journal , Volume 19 , Issue 1, 2019 May 15, {Pages 0-0 }

Abstract

Concrete is one of the most widely used building materials for fragile behavior. The addition of fiber to concrete affects the behavior of tensile strength, tensile strength, flexural strength, modulus of elasticity, impact resistance and some other mechanical properties of concrete. For this purpose, an experimental research was carried out to provide an experimental model of the flexural fatigue life of reinforced concrete with macrosynthetic fibers by constructing concrete joists with three different thicknesses of 80, 100 and 150 mm. SN models (stress-loading) and HN (thickness-loading) was presented. The results showed that increasing the thickness of concrete samples and adding fibers to concrete mixture increases the fatigue life. Al

Evaluation of Recycled Products from Worn Tires Effect on the Mechanical Properties of Concrete Pavement

Ali Zarei, Abolfazl Hassani
Journal PapersModares Civil Engineering journal , Volume 18 , Issue 6, 2019 March 15, {Pages 0-0 }

Abstract

In this research, 0, 5, 10, 15 and 20 percent of crumb rubber mix was used as a fine grained substitute for concrete pavement. Also, in another state, half percent of the steel fibers recovered from worn tires were added to these samples. The results of this study indicate that the compressive strength of samples with 5, 10, 15 and 20% crumb rubber in comparison with the control sample was reduced by 1.6, 36.9, 49.9% and 63.1%, and samples with 0, 5, 10, 15 and 20% crumb rubber and 0.5% steel fibers, respectively, decreased by 0.3, 11.2, 33.7, 5/41% and 44.3% respectively. Therefore, it is observed that the compressive strength of concrete containing crumb rubber and steel fibers is better than specimens with crumb rubber. Also, by replacin

Investigating the mechanical and hydraulic characteristics of pervious concrete containing copper slag as coarse aggregate

Ali Rezaei Lori, Abolfazl Hassani, Reza Sedghi
Journal PapersConstruction and Building Materials , Volume 197 , 2019 February 10, {Pages 130-142 }

Abstract

In this research, the mechanical and hydraulic characteristics of pervious concrete incorporating copper slag coarse aggregate were investigated. Generally, seven main mixes including 0%, 20%, 40%, 50%, 60%, 80%, and 100% replacement of dolomite aggregate with copper slag were considered in this study. The results of mechanical strength tests revealed that the highest increase in strength compared to the control mix was related to 60% replacement, in which compressive strength, flexural strength, and splitting tensile strength increased 31%, 19% and 18%, respectively. Also, the results of the Pull-off adhesion test showed that the bonding strengths of mixes incorporating 60% copper slag (median percentage) were similar to control mixes; whi

Laboratory evaluation of treated recycled concrete aggregate in asphalt mixtures

Amir Kavussi, Abolfazl Hassani, Farbod Kazemian, Mohammad Taghipoor
Journal PapersInternational Journal of Pavement Research and Technology , Volume 12 , Issue 1, 2019 January 1, {Pages 26-32 }

Abstract

Recycled Concrete Aggregate (RCA) is considered to be a potential substitute for natural aggregates in asphalt mixtures. Despite some contradictory results achieved by researchers, it is believed that RCA treatment can improve quality of recycled asphalt mixes considerably. In this research, a two-stage treatment was applied on coarse RCA materials in order to improve their properties. The treatment was consisted of first soaking RCAs in Hydrochloric Acid (HCl); second impregnating the treated RCAs into Calcium Metasilicate (CM). The pores of RCAs were filled with CM particles. Substituting virgin aggregates with different amounts of coarse RCA materials into HMA resulted in increased tensile properties of mixes as tested in

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