Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 Effect of Combined Sulfate-Chloride Attack on Concrete Durability-A Review 103 110 2725 10.22060/ceej.2017.12315.5165 EN A.A. Ramezanianpour Civil Engineering, Amirkabir University of Technology, Tehran, Iran E. Riahi Dehkordi Civil Engineering, Amirkabir University of Technology, Tehran, Iran Journal Article 2016 12 31 ABSTRACT: Chloride and sulfate ions damage the reinforced concrete in marine environment due to the corrosion and formation of expansive products, respectively. Interaction of chloride-sulfate ions on concrete deterioration is very complicated. Little research has been conducted in this respect. In this study, the effect of chloride ions on sulfate attack and effect of sulfate ions on chloride attack were reviewed. According to the results, contradictory reports were observed in studies. However, most of the researchers believed that chloride ions mitigate the sulfate attack in combined chloride- sulfate solutions. On the other hand, regarding the influence of sulfate ions on chloride attack, some of the researchers reported the mitigating effect, but others referred to the accelerating effect. Tricalcium aluminate (C3A) content, water to cement ratio (w/c), duration of submerging, corrosive ions concentrations, cation type, type of pozzolan and its replacement are important parameters that could affect the concrete performance against combined chloride-sulfate solution.

https://ajce.aut.ac.ir/article_2725_4bbdcc0e821637155ac4217bdab70d2e.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 A Framework for Project Safety Management by Applying Social Network Analysis 111 120 2726 10.22060/ceej.2017.13322.5375 EN H. Abbasianjahromi Civil Engineering Department, K. N. Toosi University of Technology, Tehran, Iran 0000-0003-3249-2882 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 Journal Article 2017 08 22 ABSTRACT: Projects need a network of various resources such as human, equipment and material which should be used together to achieve some goals. Today, in order to better manage this network, the idea of applying social network analysis (SNA) has been introduced in the project management. Since safety issues cause important challenges in projects, in this paper, the SNA is applied to promote the project’s safety level. The main idea of this research is to find the most influential person who has the high potential for creating accidents. Specifically, to solve this problem, the authors address three main subjects: firstly, to identify the existing links in the social network of projects according to different causes of accidents, secondly to analyze the network by applying the SNA and the third, to present some strategies to manage the most influential persons based on the results of the SNA. By applying the proposed framework with six steps, firstly the accidents can be prioritized based on their density and secondly, the most influential person can be identified based on centrality. To implement the proposed framework, a case study has been reviewed and the results showed that the falling from height and HSE man are the most important accident and the most influential person, respectively.

https://ajce.aut.ac.ir/article_2726_b1c00bcd4b5183705c134b3365f8c45e.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 A Robust Optimization Model for Improving Reliability of Tuned Mass Damper 121 128 2727 10.22060/ceej.2017.12346.5180 EN Mohsen Balanian Department of Civil Engineering, University of Isfahan, Isfahan, Iran Maryam Daei Department of Civil Engineering, University of Isfahan, Isfahan, Iran Hossein Tajmir Riahi Department of Civil Engineering, University of Isfahan, Isfahan, Iran Journal Article 2017 01 04 ABSTRACT: One of the most promising and effective passive vibration control dampers is the Tuned Mass Damper (TMD). Many conventional optimization criteria are based on the implicit assumption that all parameters involved are deterministically known. Removing this assumption means to convert a conventional optimization into a robust one. In this paper, a model for the robust optimum design of TMD is provided so that the optimal design of damper by considering the uncertainties possible in the earthquake load and also the structure properties can be achieved. The structural vibration control of the main system with a single linear TMD under a stochastic dynamic load is investigated. The dynamic input is represented by a random base acceleration, modeled by a stationary filtered white noise process. It is assumed that not only mechanical parameters of the main structure but also the input spectral contents are affected by uncertainty. The standard deviation of displacement of the protected main structure (dimensionless by dividing to the unprotected one) is calculated as the deterministic objective function (OF), and to achieve a robust design the mean and standard deviation of OF are considered as a multi-objective function which shall be minimum. The damping ratio and the frequency of TMD have been selected as design parameters. The results provide the different choices for designers to select an optimal TMD based on the priority of minimum mean of the maximum displacement of the structure or the minimum dispersion in a random space.

https://ajce.aut.ac.ir/article_2727_23fc4cba066f390a8cc729c7592b6ee8.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 Comparison of Rut Susceptibility Parameters in Modified Bitumen with PPA 129 134 2736 10.22060/ceej.2017.12383.5198 EN M. Khodadadi Department of Civil & Environmental Engineering, Amirkabir University of Technology (Polytechnic), Tehran, Iran F. Moghadas Nejad Department of Civil & Environmental Engineering, Amirkabir University of Technology (Polytechnic), Tehran, Iran A. Khodaii Department of Civil & Environmental Engineering, Amirkabir University of Technology (Polytechnic), Tehran, Iran ABSTRACT: Journal Article 2017 01 09 Pavement as a multi-layer structure is subjected to various distress mechanisms such as permanent deformation (Rutting) in its service time. Rutting resistance evaluation is one of the important components of pavement management system which plays a substantial role in the effective strategic development of pavement rehabilitation and maintenance. Improving the rheological properties of bitumen using one of the various additives is one of the practical approaches to reduce the rutting potential in the asphalt mixture. In this study, basic bitumen with an 85/100 penetration grade (PG58-22) was modified by 0.5, 1.0 and 1.5% poly phosphoric acid by weight of bitumen. The rutting resistance improvement of modified bitumen was investigated according to Superpave protocol. For this purpose, temperature sweep and frequency sweep tests were performed on all bitumen at 46, 52 and 58 oC. Also, rutting resistance improvement ratio was calculated based on the Superpave specification (|G*|/sinδ), Shenoy specification (|G*|/[1-(1/sinδ×tanδ)]) and zero shear viscosity. This ratio was employed to rank these specifications. The results of this study represent an improvement in rutting resistance of modified bitumen. According to specification ranking results, it can be concluded that zero shear viscosity has more potential and credibility to predict rutting damage occurrence as compared to Superpave specification and Shenoy specification.

https://ajce.aut.ac.ir/article_2736_47fd3c87f42f55d4b233417d49c34783.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 Validation of Smartphone-Based Pavement Roughness Measures 135 144 2728 10.22060/ajce.2017.13105.5328 EN S. Firoozi Yeganeh School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran A. Mahmoudzadeh Zachry Department of Civil Engineering, Texas A&M University, Texas, USA M. A. Azizpour Manchester Business School, Manchester, United Kingdom A. Golroo Department of Civil and Environment Engineering, Amirkabir University of Technology, Tehran, Iran Journal Article 2017 07 04 Smartphones are equipped with sensors such as accelerometers, gyroscope and GPS in one cost-effective device with an acceptable level of accuracy. There have been some research studies carried out in terms of using smartphones to measure the pavement roughness. However, a little attention has been paid to investigate the validity of the measured pavement roughness by smartphones via other subjective methods such as the user opinion. This paper aims at calculating the pavement roughness data with a smartphone using its embedded sensors and investigating its correlation with a user opinion about the ride quality. In addition, the applicability of using smartphones to assess the pavement surface distresses is examined. Furthermore, to validate the smartphone sensor outputs objectively, the Road Surface Profiler is applied. Finally, a good roughness model is developed which demonstrates an acceptable level of correlation between the pavement roughness measured by smartphones and the ride quality rated by users.

https://ajce.aut.ac.ir/article_2728_5e751896e527c862bf67251a474b3819.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 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 2729 10.22060/ceej.2017.12358.5184 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 Mojtaba Azhari Department of Civil Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran Journal Article 2017 01 04 Functionally graded materials (FGMs) have been widely used in many structural applications over the past decades. The rapid growth of the FGMs is due to their remarkable mechanical and thermal properties. The mechanical buckling analysis of functionally graded ceramic-metal rectangular plates is considered in this paper. The two-variable refined plate theory (RPT), in conjunction with the bubble finite strip method, is employed for the first time to evaluate the mechanical buckling loads of rectangular FGM plates. The theory, which has a strong similarity with the classical plate theory (CPT) in many aspects, accounts for a quadratic variation of transverse shear strains across the thickness of the plate and satisfies the zero traction boundary conditions on the top and bottom surfaces of the plate without using the shear correction factor. In comparison with the ordinary finite strip method, the convergence of the bubble finite strip method is very rapid due to using bubble shape functions. The mechanical properties of the FGM plate are assumed to vary according to a power law distribution of the volume fraction of constituents. The accuracy and efficiency of the present method are confirmed by comparing the present results with those available in the literature. Furthermore, the effects of powerlaw index, plate thickness, aspect ratio, loading types and various boundary conditions on the critical buckling load of the functionally graded rectangular plates are investigated.

https://ajce.aut.ac.ir/article_2729_b7f1f29db7c23648f2bb8d6a8ee0469b.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 Effect of Fiber on Mechanical Properties and Toughness of Self-Compacting Concrete Exposed to High Temperatures 153 166 2730 10.22060/ceej.2017.12631.5236 EN A. Sadrmomtazi Civil Engineering Department, University of Guilan, Rasht, Iran B. Tahmouresi Civil Engineering Department, University of Guilan, Rasht, Iran Journal Article 2017 03 08 The weakness of concrete in tension and its brittleness under various types of loadings has resulted 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.

https://ajce.aut.ac.ir/article_2730_421b3ac5c24ee992edd6087611c60dbb.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 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 2735 10.22060/ceej.2017.12762.5262 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 S. M. Hosseini Industrial Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad,Mashhad, Iran Journal Article 2017 04 12 The meshless local Petrov-Galerkin (MLPG) method is employed for dynamic analysis of fully saturated porous materials under shock loading considering two directional functionally grading patterns in constitutive mechanical properties. To approximate the trial functions in the radial point interpolation method (RPIM), the radial basis functions (RBFs) are utilized. The mechanical properties are simulated using a non-linear grading model with the radial and axial exponent. The 2D propagation of displacement and stresses are tracked through radial and axial direction in a two dimensional domain for various grading patterns at different time instants. By employing the presented meshless technique, the effects of various grading patterns on maximum values of stresses and displacements are studied in detail. The variation in the value of radial exponent has a significant effect on the dynamic behavior of radial displacement and radial stress comparing to the variation in the value of axial exponent. The MLPG method has a high capability to track the stress and displacement wave fronts at every arbitrary time instant in 2D domain.

https://ajce.aut.ac.ir/article_2735_1d49780520898fe37f0cd6b41c5311bf.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 An Overview of the Effects of High-Strength Reinforcement (HSR) on the Intermediate Moment-Resisting Frames 177 188 2731 10.22060/ceej.2017.12406.5207 EN A. Kheyroddin Department of Civil Engineering, Semnan University, Semnan, Iran H. Arshadi Department of Civil Engineering, Semnan University, Semnan, Iran F. Binaipur Department of Civil Engineering, Semnan University, Semnan, Iran Journal Article 2017 01 14 Increasing volume of constructions and necessity of having economic structures lead to the production of high-strength reinforcement (HSR). HSRs have many benefits; however, because of limitation in producing ductile HSR and the effect of HSR in the reduction of overall ductility of reinforced concrete structures, its application has been limited in seismic prone areas especially in special Reinforced concrete(RC) 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.

https://ajce.aut.ac.ir/article_2731_08f38e0434442128fab5ead6217ca759.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 Mechanical Properties of Open Graded Asphalt Mixtures with Pumice Aggregate 189 194 2732 10.22060/ceej.2017.13383.5396 EN Gh. H. Hamedi Faculty of Engineering, University of Guilan, Rasht, Iran M. R. Esmaeeli Faculty of Civil Engineering, Iran University of Science and Technology, Tehran, Iran Journal Article 2017 09 03 Open graded asphalt is used as a wearing course to provide both increased safety in wet weather (through reduced surface water and spray during rain) and reduced noise levels. In this study, Pumice aggregates were applied as a portion of fine aggregate for the improvement of dynamical specification of porous asphalt and the Cantabro, Los Angeles abrasion, and the bitumen precipitation tests were conducted. First, the amount of optimized bitumen related to each of the three types of aggregates and fine Pumice has been estimated, then the properties of the Marshall Resistance and indirect tensile strength have been assigned. Mixtures with 5 percent of fine Pumice has shown better characteristics in Marshall test as well as indirect tensile strength. Also, the results of dynamic creep test showed that the rutting potential decreased by using Pumice aggregate. There is the best amount of permanent deformation for mixtures containing 5% Pumice

https://ajce.aut.ac.ir/article_2732_361440528766bbaaaa1901845cf4152b.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 Support Vector Machine to predict the discharge coefficient of Sharp crested w-planform weirs 195 204 2733 10.22060/ceej.2017.13005.5309 EN A. Parsaie Water Engineering Department, Lorestan University, Khorramabad, Iran 0000-0001-7312-0634 A. H. Haghiabi Water Engineering Department, Lorestan University, Khorramabad, Iran Journal Article 2017 06 11 In this paper, the discharge coefficient (Cd) of triangular labyrinth weir was predicted using Multilayer Perceptron Neural Network (MLPNN), Radial Basis Neural Network (RBFNN) and support vector machine (SVM). To this end, 223 data sets related to the effective parameters on Cd were collected. Using dimensional analysis techniques, the involved dimensionless parameters on Cd were derived. To find out the most effective parameters on Cd, the Gamma test (GT) was analyzed. Results of GT demonstrated that H/P, Lw/Lc, and Lw/Wm are the most effective parameters on Cd. To develop ANN and SVM, different types of transfer and kernel functions were tested. During the testing of transfer and kernel functions for developing the ANN and SVM models, respectively, it was found that tensing and RBFNN have the best performance for predicting the Cd. Overall evaluation of the results of developed models indicated that both models have a suitable accuracy in predicting the Cd; however, the SVM is a bit more accurate. Comparing the outcomes of the applied models in terms of DDR index shows that the data dispersivity of SVM is less than the others; therefore, this model is more reliable.

https://ajce.aut.ac.ir/article_2733_ec1f850d934f440cfa8e4a18d2cf5463.pdf

Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 An Investigation on the Effect of Aggregates Packing Density on the Properties of High-Performance Concrete Mixtures 205 214 2734 10.22060/ceej.2017.12730.5263 EN H. Madani Civil Engineering Faculty, Graduate University of Advanced Technology, Haftbagh Exp. Way, Kerman, Iran 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 Journal Article 2017 04 13 This study aims to investigate the influence of dry packing density of aggregates on the mechanical and durability properties of high-performance concrete (HPC) mixtures. For this purpose, four different aggregate gradations were investigated, including ideal Fuller-Thompson curve (F), ideal Andreasen- Andersen curve (A) and their modified Funk and Dinger forms (MA and MF). The sequence of dry packing density of the aggregate gradations was as A >F>MA>MF. However, in contrast to the dry packing density results, the mixtures with the MF curve outperformed those with the other aggregate gradations in the durability and mechanical properties. Likewise, the mixture with the ideal Andreasen-Andersen curve (A) had lower compressive strengths and a higher diffusivity. Thus, the results indicated that the packing density of dry aggregates could not be indicative of the packing density of concrete and consequently the durability and mechanical characteristics of HPC. Moreover, the differences between the properties of the mixtures were more evident at lower w/cm ratios especially at w/cm of 0.31. For instance, the difference between the compressive strength of HPC mixtures with the MF and An aggregate gradations was about 14 MPa over 28 days. This study has been carried out on the concrete mixtures with compressive strengths up to 110 MPa.

https://ajce.aut.ac.ir/article_2734_7f7c351ee977c765aa8cd5c7020bc38f.pdf