Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
Effect of Combined Sulfate-Chloride Attack on Concrete Durability-A Review
103
110
EN
A.A.
Ramezanianpour
Civil Engineering, Amirkabir University of Technology, Tehran, Iran
aaramce@aut.ac.ir
E.
Riahi Dehkordi
Civil Engineering, Amirkabir University of Technology, Tehran, Iran
erfan.riahi@aut.ac.ir
10.22060/ceej.2017.12315.5165
ABSTRACT: Chloride and sulfate ions damage the reinforced concrete in marine environment due to<br />the corrosion and formation of expansive products, respectively. Interaction of chloride-sulfate ions on<br />concrete deterioration is very complicated. Little research has been conducted in this respect.<br />In this study, the effect of chloride ions on sulfate attack and effect of sulfate ions on chloride attack were<br />reviewed. According to the results, contradictory reports were observed in studies. However, most of the<br />researchers believed that chloride ions mitigate the sulfate attack in combined chloride- sulfate solutions.<br />On the other hand, regarding the influence of sulfate ions on chloride attack, some of the researchers<br />reported the mitigating effect, but others referred to the accelerating effect. Tricalcium aluminate (C3A)<br />content, water to cement ratio (w/c), duration of submerging, corrosive ions concentrations, cation type,<br />type of pozzolan and its replacement are important parameters that could affect the concrete performance<br />against combined chloride-sulfate solution.
Review,Combined effect,Sulfate,Chloride,Concrete durability
https://ajce.aut.ac.ir/article_2725.html
https://ajce.aut.ac.ir/article_2725_e9b084e27cd5e6c854a485d8e3d91a7e.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
A Framework for Project Safety Management by Applying Social Network Analysis
111
120
EN
H.
Abbasianjahromi
0000-0003-3249-2882
Civil Engineering Department, K. N. Toosi University of Technology, Tehran, Iran
habasian@kntu.ac.ir
M.
Sepehri
Graduate School of Management, Sharif University of Technology, Tehran, Iran
A.
Etemadi
Department of Civil Engineering, Kish International Branch, Islamic Azad University, Kish Island, Iran
10.22060/ceej.2017.13322.5375
ABSTRACT: Projects need a network of various resources such as human, equipment and material<br />which should be used together to achieve some goals. Today, in order to better manage this network, the<br />idea of applying social network analysis (SNA) has been introduced in the project management. Since<br />safety issues cause important challenges in projects, in this paper, the SNA is applied to promote the<br />project’s safety level. The main idea of this research is to find the most influential person who has the<br />high potential for creating accidents. Specifically, to solve this problem, the authors address three main<br />subjects: firstly, to identify the existing links in the social network of projects according to different<br />causes of accidents, secondly to analyze the network by applying the SNA and the third, to present<br />some strategies to manage the most influential persons based on the results of the SNA. By applying the<br />proposed framework with six steps, firstly the accidents can be prioritized based on their density and<br />secondly, the most influential person can be identified based on centrality. To implement the proposed<br />framework, a case study has been reviewed and the results showed that the falling from height and HSE<br />man are the most important accident and the most influential person, respectively.
Safety Management,Social Network Analysis,Construction industry,HSE,Centrality
https://ajce.aut.ac.ir/article_2726.html
https://ajce.aut.ac.ir/article_2726_ecdf66ef1771d1667e79df614934aacf.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
A Robust Optimization Model for Improving Reliability of Tuned Mass Damper
121
128
EN
Mohsen
Balanian
Department of Civil Engineering, University of Isfahan, Isfahan, Iran
Maryam
Daei
Department of Civil Engineering, University of Isfahan, Isfahan, Iran
m.daei@eng.ui.ac.ir
Hossein
Tajmir Riahi
Department of Civil Engineering, University of Isfahan, Isfahan, Iran
10.22060/ceej.2017.12346.5180
ABSTRACT: One of the most promising and effective passive vibration control dampers is the Tuned<br />Mass Damper (TMD). Many conventional optimization criteria are based on the implicit assumption that all<br />parameters involved are deterministically known. Removing this assumption means to convert a conventional<br />optimization into a robust one. In this paper, a model for the robust optimum design of TMD is provided so<br />that the optimal design of damper by considering the uncertainties possible in the earthquake load and also<br />the structure properties can be achieved. The structural vibration control of the main system with a single<br />linear TMD under a stochastic dynamic load is investigated. The dynamic input is represented by a random<br />base acceleration, modeled by a stationary filtered white noise process. It is assumed that not only mechanical<br />parameters of the main structure but also the input spectral contents are affected by uncertainty. The standard<br />deviation of displacement of the protected main structure (dimensionless by dividing to the unprotected one) is<br />calculated as the deterministic objective function (OF), and to achieve a robust design the mean and standard<br />deviation of OF are considered as a multi-objective function which shall be minimum. The damping ratio and<br />the frequency of TMD have been selected as design parameters. The results provide the different choices for<br />designers to select an optimal TMD based on the priority of minimum mean of the maximum displacement of<br />the structure or the minimum dispersion in a random space.
Tuned Mass Damper,State Space Equation,Passive control,Uncertainty,Robust Optimization
https://ajce.aut.ac.ir/article_2727.html
https://ajce.aut.ac.ir/article_2727_233d686a55b2823f8bd0e9503582cf8c.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
Comparison of Rut Susceptibility Parameters in Modified Bitumen with PPA
129
134
EN
M.
Khodadadi
Department of Civil & Environmental Engineering, Amirkabir University of Technology (Polytechnic), Tehran, Iran
F.
Moghadas Nejad
0000-0003-3830-4555
Department of Civil & Environmental Engineering, Amirkabir University of Technology (Polytechnic), Tehran, Iran
moghadas@aut.ac.ir
A.
Khodaii
Department of Civil & Environmental Engineering, Amirkabir University of Technology (Polytechnic), Tehran, Iran
ABSTRACT:
10.22060/ceej.2017.12383.5198
Pavement as a multi-layer structure is subjected to various distress mechanisms such<br />as permanent deformation (Rutting) in its service time. Rutting resistance evaluation is one of the<br />important components of pavement management system which plays a substantial role in the effective<br />strategic development of pavement rehabilitation and maintenance. Improving the rheological properties<br />of bitumen using one of the various additives is one of the practical approaches to reduce the rutting<br />potential in the asphalt mixture. In this study, basic bitumen with an 85/100 penetration grade (PG58-22)<br />was modified by 0.5, 1.0 and 1.5% poly phosphoric acid by weight of bitumen. The rutting resistance<br />improvement of modified bitumen was investigated according to Superpave protocol. For this purpose,<br />temperature sweep and frequency sweep tests were performed on all bitumen at 46, 52 and 58 oC. Also,<br />rutting resistance improvement ratio was calculated based on the Superpave specification (|G*|/sinδ),<br />Shenoy specification (|G*|/[1-(1/sinδ×tanδ)]) and zero shear viscosity. This ratio was employed to rank<br />these specifications. The results of this study represent an improvement in rutting resistance of modified<br />bitumen. According to specification ranking results, it can be concluded that zero shear viscosity has more<br />potential and credibility to predict rutting damage occurrence as compared to Superpave specification<br />and Shenoy specification.
Rutting of Asphalt Mixture,Rheological Properties of Modified Bitumen,Superpave Protocol,Zero Shear Viscosity,Poly Phosphoric Acid
https://ajce.aut.ac.ir/article_2736.html
https://ajce.aut.ac.ir/article_2736_e0fe1ef2bfb7664bdee7070c0ce8f7ee.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
Validation of Smartphone-Based Pavement Roughness Measures
135
144
EN
S.
Firoozi Yeganeh
School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran
sfiroozi@aut.ac.ir
A.
Mahmoudzadeh
Zachry Department of Civil Engineering, Texas A&M University, Texas, USA
a.mahmoudzadeh@aut.ac.ir
M. A.
Azizpour
Manchester Business School, Manchester, United Kingdom
aminazp@yahoo.com
A.
Golroo
Department of Civil and Environment Engineering, Amirkabir University of Technology, Tehran, Iran
agolroo@aut.ac.ir
10.22060/ajce.2017.13105.5328
Smartphones are equipped with sensors such as accelerometers, gyroscope and GPS in<br />one cost-effective device with an acceptable level of accuracy. There have been some research studies<br />carried out in terms of using smartphones to measure the pavement roughness. However, a little attention<br />has been paid to investigate the validity of the measured pavement roughness by smartphones via other<br />subjective methods such as the user opinion. This paper aims at calculating the pavement roughness<br />data with a smartphone using its embedded sensors and investigating its correlation with a user opinion<br />about the ride quality. In addition, the applicability of using smartphones to assess the pavement surface<br />distresses is examined. Furthermore, to validate the smartphone sensor outputs objectively, the Road<br />Surface Profiler is applied. Finally, a good roughness model is developed which demonstrates an<br />acceptable level of correlation between the pavement roughness measured by smartphones and the ride<br />quality rated by users.
Pavement roughness,smartphone,user opinion
https://ajce.aut.ac.ir/article_2728.html
https://ajce.aut.ac.ir/article_2728_7b6e80ea733444f0b873878e6ad38b06.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
Buckling Analysis of Functionally Graded Plates Based on Two-Variable Refined Plate Theory Using the Bubble Finite Strip Method
145
152
EN
Omid
Kianian
Department of Civil Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
Saeid
Sarrami-Foroushani
Department of Civil Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
sarrami@cc.iut.ac.ir
Mojtaba
Azhari
Department of Civil Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
10.22060/ceej.2017.12358.5184
Functionally graded materials (FGMs) have been widely used in many structural<br />applications over the past decades. The rapid growth of the FGMs is due to their remarkable mechanical<br />and thermal properties. The mechanical buckling analysis of functionally graded ceramic-metal<br />rectangular plates is considered in this paper. The two-variable refined plate theory (RPT), in conjunction<br />with the bubble finite strip method, is employed for the first time to evaluate the mechanical buckling<br />loads of rectangular FGM plates. The theory, which has a strong similarity with the classical plate theory<br />(CPT) in many aspects, accounts for a quadratic variation of transverse shear strains across the thickness<br />of the plate and satisfies the zero traction boundary conditions on the top and bottom surfaces of the<br />plate without using the shear correction factor. In comparison with the ordinary finite strip method, the<br />convergence of the bubble finite strip method is very rapid due to using bubble shape functions. The<br />mechanical properties of the FGM plate are assumed to vary according to a power law distribution of<br />the volume fraction of constituents. The accuracy and efficiency of the present method are confirmed by<br />comparing the present results with those available in the literature. Furthermore, the effects of powerlaw<br />index, plate thickness, aspect ratio, loading types and various boundary conditions on the critical<br />buckling load of the functionally graded rectangular plates are investigated.
Functionally graded plate,Refined plate theory,Buckling,Finite strip method,Bubble function
https://ajce.aut.ac.ir/article_2729.html
https://ajce.aut.ac.ir/article_2729_8f49102852d628752da838d03a5a9424.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
Effect of Fiber on Mechanical Properties and Toughness of Self-Compacting Concrete Exposed to High Temperatures
153
166
EN
A.
Sadrmomtazi
Civil Engineering Department, University of Guilan, Rasht, Iran
sadrmomtazi@yahoo.com
B.
Tahmouresi
Civil Engineering Department, University of Guilan, Rasht, Iran
10.22060/ceej.2017.12631.5236
The weakness of concrete in tension and its brittleness under various types of loadings has resulted<br />in using different and convenient fibers, including steel and poly propylene, which in addition increasing of ductility and improvement in post-cracking behavior of concrete, have a major role in minimizing shrinkage and thermal cracks. In this study, the effects of high temperatures (200, 300, 400 and 600 ͦ C) on compressive strength, splitting strength, flexural strength and energy absorption capacity or toughness of self-compacting concretes containing steel, polypropylene and polyethylene terephthalate (PET) fibers were evaluated. The test results on fresh concrete imply that the increase in fibers make some criteria of self-compacting concrete unachievable. Compared to the unheated non-fiber specimens (SCC2), increasing temperature up to 600oC decreased compressive strength at steel, polypropylene and PET fiber containing specimens 30, 37.5 and 34.5%, respectively. However, residual strengths were 22, 8 and 13% higher than the heated non-fiber specimens. At 600 oC, flexural toughness and maximum flexural load were 5 and 1.8 times higher than control specimens. Adding fibers had a positive effect on specimens’ explosive spalling so that spalling threshold was shifted to higher temperature levels. The proposed relationships and models at the elevated temperature are compared with experimental results. These results are used to predict more accurate and general compressive and splitting strengths, flexural strength, elasticity modulus, flexural load peak-point and flexural deflection relationships.
SCC,Fibers,Toughness,High Temperatures,Spalling
https://ajce.aut.ac.ir/article_2730.html
https://ajce.aut.ac.ir/article_2730_2c55092f2a1574a535184004e3164453.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
Two Dimensional Stress and Displacement Wave Propagation Under Shock Loading in Saturated Porous Materials with Two Dimensional Functionally Graded Materails Using MLPG Method
167
176
EN
H.
Kazemi
Civil Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
F.
Shahabian
Civil Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
shahabf@um.ac.ir
S. M.
Hosseini
Industrial Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad,Mashhad, Iran
sm_hosseini@um.ac.ir
10.22060/ceej.2017.12762.5262
The meshless local Petrov-Galerkin (MLPG) method is employed for dynamic analysis<br />of fully saturated porous materials under shock loading considering two directional functionally grading<br />patterns in constitutive mechanical properties. To approximate the trial functions in the radial point<br />interpolation method (RPIM), the radial basis functions (RBFs) are utilized. The mechanical properties<br />are simulated using a non-linear grading model with the radial and axial exponent. The 2D propagation<br />of displacement and stresses are tracked through radial and axial direction in a two dimensional domain<br />for various grading patterns at different time instants. By employing the presented meshless technique,<br />the effects of various grading patterns on maximum values of stresses and displacements are studied<br />in detail. The variation in the value of radial exponent has a significant effect on the dynamic behavior<br />of radial displacement and radial stress comparing to the variation in the value of axial exponent. The<br />MLPG method has a high capability to track the stress and displacement wave fronts at every arbitrary<br />time instant in 2D domain.
Porous materials,Stress wave propagation,Displacement wave propagation,MLPG method,Radial basis functions
https://ajce.aut.ac.ir/article_2735.html
https://ajce.aut.ac.ir/article_2735_f3d217f02b324b63101de1252a03cca2.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
An Overview of the Effects of High-Strength Reinforcement (HSR) on the Intermediate Moment-Resisting Frames
177
188
EN
A.
Kheyroddin
Department of Civil Engineering, Semnan University, Semnan, Iran
kheyroddin@semnan.ac.ir
H.
Arshadi
Department of Civil Engineering, Semnan University, Semnan, Iran
F.
Binaipur
Department of Civil Engineering, Semnan University, Semnan, Iran
10.22060/ceej.2017.12406.5207
Increasing volume of constructions and necessity of having economic structures lead to the<br />production of high-strength reinforcement (HSR). HSRs have many benefits; however, because of limitation<br />in producing ductile HSR and the effect of HSR in the reduction of overall ductility of reinforced concrete<br />structures, its application has been limited in seismic prone areas especially in special Reinforced concrete(RC)<br />moment-resisting frames. In this research, the effect of HSR application on drifts, displacements, and quantity of consumed steel are studied by the linear static analysis, and also the base shear and proportionate displacements to them are studied by the nonlinear static analysis (Pushover) with ETABS software (for nine models with different numbers of stories and grades of steel). Then, the tensile strains of beams’ ends which can be a representation of cracking phenomenon in concrete are acquired conducting nonlinear dynamic analysis with Opensees. Ultimately, it is shown that although HSRs have economic benefits, they increase displacements and drifts. To compensate this issue, it is necessary to increase the rigidity of members by increasing steel quantity or dimension of members. This is a serious challenge because it neutralizes steel consumption reduction. It is also shown that by substituting the reinforcement bars for higher grade ones: the level of tensile stress in concrete alongside with the tolerated displacement in order to enter the nonlinear stage in Pushover analysis increases. Moreover, the less the grades of steel, the fewer shears are tolerated by structures.
High-strength reinforcement (HSR),displacement,Pushover,Non-linear Dynamic Analysis,Strain
https://ajce.aut.ac.ir/article_2731.html
https://ajce.aut.ac.ir/article_2731_d058b4294a64ff366d7bdff0e6ab85c9.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
Mechanical Properties of Open Graded Asphalt Mixtures with Pumice Aggregate
189
194
EN
Gh. H.
Hamedi
Faculty of Engineering, University of Guilan, Rasht, Iran
hamedi@guilan.ac.ir
M. R.
Esmaeeli
Faculty of Civil Engineering, Iran University of Science and Technology, Tehran, Iran
m.r.esmaeeli7@gmail.com
10.22060/ceej.2017.13383.5396
Open graded asphalt is used as a wearing course to provide both increased safety in<br />wet weather (through reduced surface water and spray during rain) and reduced noise levels. In this<br />study, Pumice aggregates were applied as a portion of fine aggregate for the improvement of dynamical<br />specification of porous asphalt and the Cantabro, Los Angeles abrasion, and the bitumen precipitation<br />tests were conducted. First, the amount of optimized bitumen related to each of the three types of<br />aggregates and fine Pumice has been estimated, then the properties of the Marshall Resistance and<br />indirect tensile strength have been assigned. Mixtures with 5 percent of fine Pumice has shown better<br />characteristics in Marshall test as well as indirect tensile strength. Also, the results of dynamic creep<br />test showed that the rutting potential decreased by using Pumice aggregate. There is the best amount of<br />permanent deformation for mixtures containing 5% Pumice
Open graded asphalt mixture,Pumice,Stiffness modulus,Rutting,Moisture Susceptibility
https://ajce.aut.ac.ir/article_2732.html
https://ajce.aut.ac.ir/article_2732_0df872c99139696505226f797c8b0ee9.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
Support Vector Machine to predict the discharge coefficient of Sharp crested w-planform weirs
195
204
EN
A.
Parsaie
0000-0001-7312-0634
Water Engineering Department, Lorestan University, Khorramabad, Iran
abbas_parsaie@yahoo.com
A. H.
Haghiabi
Water Engineering Department, Lorestan University, Khorramabad, Iran
10.22060/ceej.2017.13005.5309
In this paper, the discharge coefficient (Cd) of triangular labyrinth weir was predicted<br />using Multilayer Perceptron Neural Network (MLPNN), Radial Basis Neural Network (RBFNN) and<br />support vector machine (SVM). To this end, 223 data sets related to the effective parameters on Cd were<br />collected. Using dimensional analysis techniques, the involved dimensionless parameters on Cd were<br />derived. To find out the most effective parameters on Cd, the Gamma test (GT) was analyzed. Results of<br />GT demonstrated that H/P, Lw/Lc, and Lw/Wm are the most effective parameters on Cd. To develop ANN<br />and SVM, different types of transfer and kernel functions were tested. During the testing of transfer and<br />kernel functions for developing the ANN and SVM models, respectively, it was found that tensing and<br />RBFNN have the best performance for predicting the Cd. Overall evaluation of the results of developed<br />models indicated that both models have a suitable accuracy in predicting the Cd; however, the SVM is a<br />bit more accurate. Comparing the outcomes of the applied models in terms of DDR index shows that the<br />data dispersivity of SVM is less than the others; therefore, this model is more reliable.
W plan form weirs,nonlinear crest,Flow Measurement,discharge capacity,Gamma test
https://ajce.aut.ac.ir/article_2733.html
https://ajce.aut.ac.ir/article_2733_4502d239a011b061301e5447750c979f.pdf
Amirkabir University of Technology
AUT Journal of Civil Engineering
2588-2899
2588-2902
1
2
2017
12
01
An Investigation on the Effect of Aggregates Packing Density on the Properties of High-Performance Concrete Mixtures
205
214
EN
H.
Madani
Civil Engineering Faculty, Graduate University of Advanced Technology, Haftbagh Exp. Way, Kerman, Iran
h.madani@kgut.ac.ir
J.
Rostami
Civil Engineering Faculty, Graduate University of Advanced Technology, Haftbagh Exp. Way, Kerman, Iran
M. N.
Norouzifar
Civil Engineering Faculty, Graduate University of Advanced Technology, Haftbagh Exp. Way, Kerman, Iran
H. Karimi Maleh
H. Karimi Maleh
Chamical Engineering Faculty, Graduate University of Advanced Technology, Haftbagh Exp. Way, Kerman, Iran
10.22060/ceej.2017.12730.5263
This study aims to investigate the influence of dry packing density of aggregates on the<br />mechanical and durability properties of high-performance concrete (HPC) mixtures. For this purpose, four<br />different aggregate gradations were investigated, including ideal Fuller-Thompson curve (F), ideal Andreasen-<br />Andersen curve (A) and their modified Funk and Dinger forms (MA and MF). The sequence of dry packing<br />density of the aggregate gradations was as A >F>MA>MF. However, in contrast to the dry packing density<br />results, the mixtures with the MF curve outperformed those with the other aggregate gradations in the<br />durability and mechanical properties. Likewise, the mixture with the ideal Andreasen-Andersen curve (A)<br />had lower compressive strengths and a higher diffusivity. Thus, the results indicated that the packing density<br />of dry aggregates could not be indicative of the packing density of concrete and consequently the durability<br />and mechanical characteristics of HPC. Moreover, the differences between the properties of the mixtures<br />were more evident at lower w/cm ratios especially at w/cm of 0.31. For instance, the difference between the<br />compressive strength of HPC mixtures with the MF and An aggregate gradations was about 14 MPa over 28<br />days. This study has been carried out on the concrete mixtures with compressive strengths up to 110 MPa.
High-performance concrete (HPC),Packing density,Aggregate gradation,Durability
https://ajce.aut.ac.ir/article_2734.html
https://ajce.aut.ac.ir/article_2734_f0219cb2eaf71e5d5c7fab029e620815.pdf