rahmatii

High-mode effects on seismic performance of multi-story self-centering braced steel frames Can-Xing Qiu, Songye Zhu ⁎ a The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China b Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong Seismic-resisting, multi-story steel frames with self-centering braces (SCBs) are numerically investigated through pushover and ncremental dynamic analyses. The seismic performance of self-centering braced frames (SC-BFs) is systematically compared with that of buckling-restrained braced frames (BRBFs), with emphasis on high-mode effect. The concentration of inter-story drift in the upper part of the buildings is more significant in SC-BFs than in BRBFs as a result of this effect. This high-mode effect strengthens with the increasing intensity of ground motions. Parametric studies indicate that increasing the post-yield stiffness ratio and/or energy dissipation capacity can successfully improve the seismic performance of SC-BFs, particularly in terms of limiting the high-mode effect. SC-BFs with enhanced post-yield stiffness and energy dissipation capacity exhibit relatively uniform inter-story drift ratios and reduced record-to-record variability in seismic performance. © 2015 Elsevier Ltd. All rights reserved. Keywords: Multi-story steel frame Self-centering brace (SCB) High-mode effect Post-yield stiffness ratio Energy dissipation capacity 10.1016_j.jcsr.2015.12.008-High-mode-effects-on-seismic-performance-of-multi-story-self-centering-braced-steel-frames.pdf

Influence of using nonmaterial to reduce the moisture susceptibility of hot mix asphalt F. Moghadas Nejad a , A.R. Azarhoosh b, GH.H. Hamedi a, M.J. Azarhoosh c a Department of Civil & Environmental Engineering, Amirkabir University of Technology, Tehran 15875, Iran b Department of Civil Engineering, University of Guilan, Rasht, Iran c Department of Chemical Engineering, Amirkabir University of Technology, Tehran, Iran a b s t r a c t Moisture damage in an asphalt mixture can be defined as the loss of strength, stiffness and durability due to the presence of moisture leading to adhesive failure at the binder–aggregate interface and/or cohesive failure within the binder or binder–filler mastic. In order to improve adhesion and reduce moisture sensitivity in asphalt mixtures, two different approaches have become apparent. One approach suggests that the aggregate surface be coated by a suitable agent thatwill reverse the predominant electrical charges at the surface and thus reduce the surface energy of the aggregate. In this study, the effects of nanomaterial, namely Zycosoil, on the moisture damage of asphalt mixtures were studied.Two types of aggregates that represent a considerable range in mineralogy, limestone and granite, were evaluated during the course of this study. To assess the impact of Zycosoil on moisture damage of hot mix Asphalt, control mixes (without Zycosoil) and mixes containing Zycosoil in dry and wet conditions were tested using indirect tensile-strength (ITS) and indirect tensile fatigue (ITF) tests. The results showed that limestone has lessmoisture damage potential compared to granite. The ratio of wet/dry values of ITST and ITFT for mixes containing Zycosoil was higher than the control mix for two types of aggregate. However, in mixtures made of granite aggregate, using Zycosoil ismore effective. As the density of silanol groups ismore in its surface, these groups are hydrophilic, and Zycosoil migrates to the polar water-loving surface, reacts with the silanol groups and forms siloxane bond, the strongest bond in nature, and creates a molecular level hydrophobic zone. Crown Copyright 2012 Published by Elsevier Ltd. All rights reserved Keywords Moisture damage Zycosoil Indirect tensile-strength Fatigue Silanol group Siloxane bond. elearnica.ir-Influence_of_using_nonmaterial_to_reduce_the_moisture_susceptib.pdf

Evaluating the Effect of Zycosoil on Moisture Damage of Hot-Mix Asphalt Using the Surface Energy Method A. Khodaii1; V. Khalifeh2; M. H. Dehnad3; and Gh. H. Hamedi4 Abstract: There are several approaches for improving adhesion and moisture sensitivity in asphalt mixtures, one of which is to coat the aggregate surface with a suitable agent to change the predominant electrical charges at the surface and reduce the surface energy of the aggregate. In this study, the effects of using Zycosoil as an antistripping additive on moisture susceptibility of asphalt mixtures has been evaluated by determining the mechanism that affects the adhesive bond between the aggregate and asphalt binder using the surface free energy (SFE) method and laboratory dynamic modulus test. The percentage of the aggregate surface exposed to water (P index) has also been calculated by using the measured SFE and dynamic modulus results, and evaluated as an index for the moisture susceptibility of mixtures. The results of the SFE method show that Zycosoil decrease the difference between the free energy of the adhesion of aggregateasphalt binder in dry and wet conditions, and this difference is equal to the amount of energy released when stripping occurs. Coating of the aggregate surface with Zycosoil decreases this difference, and subsequently causes the mixture to be more resistant to moisture damage. DOI: 10.1061/(ASCE)MT.1943-5533.0000819. © 2014 American Society of Civil Engineers . Author keywords: HMA; Moisture damage; Surface free energy; Antistripping. elearnica.ir-Evaluating_the_Effect_of_Zycosoil_on_Moisture_Damage_of_Hot-Mix.pdf

دانلود پلان معماری 5 طبقه مسکونی ابعاد 14.35*15.55- شامل : پلان معماری ومبلمان زیرزمین ، طبقات وبام 2 نما 2 سکشن 5پرسپکتیو (طراحی وترسیم توسط اینجانب صورت گرفته است.) Alghame.rar

Development of an Innovative Uniaxial Compression Test to Evaluate Permanent Deformation of Asphalt Mixtures Xingyu Gu, Ph.D.1; Qiao Dong, Ph.D., A.M.ASCE2; and Qingquan Yuan3 Abstract: An innovative uniaxial compression test, capable of simulating the confinement and temperature condition in actual pavement, was developed in this study to evaluate the deformation of asphalt mixtures. Small-diameter loading head was utilized to create a confinement inside the specimen, which is similar to that in the field. Optimized loading head size was determined to provide the best confining effect. To reproduce the actual pavement temperature distribution in the tested specimen, a finite-element method (FEM) model was first developed to predict temperature at different depths of a pavement. Then, the laboratory temperature control system was calibrated by monitoring the temperature inside a dummy specimen to ensure the temperatures at different depths of the specimen are the same as in the pavement Cylindrical specimens with different composition of mixtures were prepared for the uniaxial test to evaluate the deformation of the typical pavement structure at various temperatures, vehicle speeds, and load levels. The developed test method clearly differentiated different materials and reflected the influence of temperature, load time, and level. Test results showed high temperature increased the permanent stain. When the highest ambient temperature level was higher than 28°C, the test effectively differentiated different types of materials. In addition, low vehicle speed and overload significantly increased rutting potential of pavement. DOI: 10.1061/(ASCE)MT.1943-5533 .0001038. © 2014 American Society of Civil Engineers. Author keywords: Pavement permanent deformation; Asphalt mixture; Pavement temperature; Uniaxial compression test; Confinement stress; Vehicle speed; Overload. elearnica.ir-Development_of_an_Innovative_Uniaxial_Compression_Test_to_Evaluate_Permanen.pdf

Applying Method of Moments to Model the Reliability of Deteriorating Performance to Asphalt Pavement under Freeze-Thaw Cycles in Cold Regions Biao Ma, Ph.D.1; Wei Si2; Dong-peng Zhu3; and Hai-nian Wang, Ph.D.4 Abstract: Accurate deterioration models play a critical role in designing and managing transportation infrastructure. Regular models simply consider loading factor and its relative uncertainties. However, climate and environment impacts are not considered, or are just used as certain variables. Thermal cracks and moisture distresses are principal distress forms in cold regions. In this study, a freeze-thaw (F-T) cycle test was used to simulate the influence of adverse weather conditions in cold regions, like moisture and temperature impact. Then method of moments was applied to analyze the pavement reliability functions with various uncertainties. The analytical results showed that the resilient modulus of asphalt concrete mixture declined under F-T cycles. Consequently, pavement structure capacity was reduced. The results also illustrated that the reliability method was capable of accommodating uncertainties in pavement parameters. The sensitivity analysis indicated that F-T cycles had a significant impact on estimating reliability, especially with a large coefficient of variance. The larger the coefficient of variance the faster the decline in reliability. Reliability analysis results indicate that a decrease in the variability of F-T cycles can significantly increase the estimated reliability. As a result, F-T cycles with uncertainty harm the pavement loading capacity, which should not be neglected in actual engineering. This paper also proposes some instructions for simulating pavement performance models. DOI: 10.1061/(ASCE)MT.1943- 5533.0001027. © 2014 American Society of Civil Engineers. Author keywords: Freeze-thaw cycle test; Resilient modulus; Reliability method; Method of moments; Fragility curves. elearnica.ir-Applying_Method_of_Moments_to_Model_the_Reliability_of_Deteriorating_Perfor.rar