Sharif University of TechnologyScientia Iranica1026-309816220090401Study of Early-Age Creep and Shrinkage of Concrete Containing Iranian Pozzolans: An Experimental Comparative Study3184ENH.KetabchiDepartment of Civil Engineering,Sharif University of TechnologyM.H.AfsharDepartment of Civil Engineering,Iran University of Science and TechnologyP.GhodousiDepartment of Civil Engineering,Iran University of Science and TechnologyE.RasaDepartment of Civil and Environmental Engineering,University of CaliforniaJournal Article20090606Abstract. This paper presents an experimental study on prediction of the early-age creep and shrinkage
of concrete with and without silica fumes, trass, ground-granulated blast-furnace slag, combinations
thereof, and in
uences of the proposed Iranian pozzolans. Experiments were carried out under a controlled
ambient condition at a temperature of 40C and a relative humidity (RH) of 50%, and a laboratory ambient
condition at a temperature of 20C and a relative humidity (RH) of 30% in order to collect the required
data. Comparisons are made between ACI209-92, BS8110-1986 and CEB1970 prediction models, and an
estimation model, based on 28-day results (short-term test method), using the same experimental data to
predict the creep and shrinkage of the specimens at the ages of 120 and 200 days after curing. The results
show that the above-mentioned models are not accurate enough for predicting the creep and shrinkage of
concrete containing local Iranian pozzolans. It was also observed that the prediction, based on short-term
results, would lead to more accurate creep and shrinkage predictions.https://scientiairanica.sharif.edu/article_3184_40f17225715a639e559d1cabf3d4e7fa.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Making a Decision Between the Rehabilitation and Reconstruction of Asphalt Pavements Using the Rough-Set Theory3185ENM.ArabaniDepartment of Civil Engineering,Guilan UniversityA.K.HaghiFaculty of Engineering,Guilan UniversityB.AmaniFaculty of Engineering,Guilan UniversityJournal Article20090606Abstract. Every year a great amount of money is expended for the rehabilitation and reconstruction
of roads and pavements in most countries. Besides, making an ideal decision on this based on the
types of failures determined, takes too long. The rough-set theory is an e ective tool for the analysis
of information systems in a Pavement Management System (PMS) database gained by both objective and
subjective methods. A rough-set based analysis acts like a knowledge engineer who sits between data and
the user. This approach appears to capture information on uncertainty, imprecision and ambiguity along
with precise values in a PMS database. This paper explores a new approach to the rough-set theory in
a PMS database that enables pavement engineers to discover the shortest subsets of condition attributes
having quality equal to the general quality of de ned characteristics in the information system, to assess
and describe pavement conditions, and to derive decision rules for rehabilitation and reconstruction of the
pavements. To evaluate the results, the best algorithm of de ned attributes in the information system is
determined by making use of a stepwise linear regression method and the result is compared with rough-set
ones. The results of the research indicate that the rough-set theory has a better and stronger operational
capability in identifying the e ective parameters for the severity evaluation of typical distresses in asphalt
pavements and in decision-making for selecting the type of repair.https://scientiairanica.sharif.edu/article_3185_6b390b6b9092ec1657aee0698178adbf.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Correlation Between Structural Performance Levels and Damage Indexes in Steel Frames Subjected to Earthquakes3186ENH.E.EstekanchiDepartment of Civil Engineering,Sharif University of TechnologyA.VafaiDepartment of Civil Engineering,Sharif University of TechnologyK.ArjomandiDepartment of Civil Engineering,Sharif University of TechnologyJournal Article20090606Abstract. Various damage indexes have been introduced in recent years incorporating di erent
parameters for estimating structural damage. Amongst these indexes, Plastic Ductility and Drift have been
the center of attention of standards and building codes, like FEMA-356, because of their straightforward
physical interpretation and ease of calculation. In this paper, several steel moment frames have been
considered and their responses have been evaluated under a set of scaled earthquakes. A group of various
damage indexes, which included cumulative and non cumulative, cyclic fatigue based, deformation based
and modal parameter based, has been considered and the damage to structures has been evaluated on their
basis. On the other hand, the performance levels of the frames have been estimated on the basis of the
FEMA-356 standard. Based on these results, the correlation between FEMA performance levels and the
values of damage indexes has been studied and some polynomial equations have been proposed. These
simple equations can be used to estimate the value of the damage indexes from FEMA performance levels.
Also, the range of each damage index for each FEMA performance level has been determined. At last,
based on the concepts underlying each damage index, the indications of some important aspects of the
structure response correlated to each FEMA performance level are investigated.https://scientiairanica.sharif.edu/article_3186_3c8ec773e4c8ec148bbac354e930b8bc.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Wave Parameter Hindcasting in a Lake Using the SWAN Model3187ENA.Etemad-ShahidiDepartment of Civil Engineering,Iran University of Science and TechnologyM.H.MoeiniDepartment of Civil Engineering,Iran University of Science and TechnologyJournal Article20090606Abstract. Wind-induced wave characteristics are one of the most important factors in the design
of coastal and marine structures. Therefore, accurate estimation of wave parameters is of considerable
importance. The wave climate study can be conducted by eld measurements, empirical studies, physical
modeling and numerical simulations. In this paper, the skill of a third-generation spectral model called
SWAN has been evaluated in the prediction of wave parameters. The varying wind and wave climate of
Lake Erie in the year 2002 has been used for evaluation of the model. The signi cant wave height (Hs)
and the peak spectral wave period (Tp) were the parameters employed in the study and the model has
been executed in a nonstationary mode. The linear and exponential growth from wind input, four-wave
nonlinear interaction, whitecapping and bottom friction have been considered in the simulation. The results
of this study show that in the investigated case, the average scatter index of SWAN is about 19 percent for
signi cant wave height and 23 percent for the peak period. The error of the SWAN model in prediction of
the wave height and period reduced about 3 percent after elimination of wave heights less than 0.5 meters.
It was also found that using the cumulative steepness method for whitecapping dissipation yields worse
results for signi cant wave height and better results for peak spectral period estimation. After using this
method, the average scatter index for the prediction of Hs increased about 5 percent and decreased more
than 4 percent for Tp. It should be mentioned that the computational time required by using this method
is approximately more than twice that of the Komen option.https://scientiairanica.sharif.edu/article_3187_bcb95d014403256348ead6aec2df0032.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Cement-Based Solidi cation/Stabilization of Heavy Metal Contaminated Soils with the Objective of Achieving High Compressive Strength for the Final Matrix3188ENH.GanjidoustDepartment of Civil Engineering,Tarbiat Modares UniversityA.HassaniDepartment of Civil Engineering,Tarbiat Modares UniversityA.Rajabpour AshkikiDepartment of Civil Engineering,Tarbiat Modares UniversityJournal Article20090606Abstract. The Solidi cation/Stabilization (S/S) of heavy metal contaminated soils using Ordinary
Pontlandite Cement (OPC) is studied as a hazardous waste treatment technology. The soil-binder ratio
of 8% by weight is selected for treatment by setting a justi cation constraint on the solidi ed matrix.
In order to consider the physical and chemical characteristics of the solidi ed soil-cement mixtures,
Compressive Strength, Toxicity Characteristic Leaching Procedure (TCLP), X-Ray Di raction (XRD)
and Scanning Electron Microscopy (SEM) are the tests done during this research. The results indicate
that despite an intensive decrease in the compressive strength of solidi ed soil at early curing ages, the
justi cation constraint set on the preparation of specimens enhances hydration reactions; and the solidi ed
matrix achieves high compressive strength after 7 curing days. The leaching metal concentration in
leachates is decreased gradually by aging from 1 to 28 curing days, indicating more metal stabilization
in the form of metal hydroxide precipitation, which presents itself in the developed crystalline phases
of hydrated cement, as observed in XRD patterns or by absorption on CSH gel or crystals. Leaching
metal concentration in leachates is lower than regulatory limits, so there is no strength concern for
environmentally safe disposal. Heavy metal contamination diverts the cement hydration reactions toward
production of more subsidiary products, that bear less compressive strength, instead of main hydration
products. Therefore, the main crystalline phases develop irregularly and coat the aggregates poorly, as
observed in SEM micrographs.https://scientiairanica.sharif.edu/article_3188_4ef5e23785aecdfabbd7e22400c271aa.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Bending Response of HSRC Beams Strengthened with FRP Sheets3189ENS.H.HashemiFaculty of Engineering,Razi Metallurgical Research CenterA.A.MaghsoudiDepartment of Civil Engineering,Razi Metallurgical Research CenterR.RahgozarDepartment of Civil Engineering,Razi Metallurgical Research CenterJournal Article20090606Abstract. The repair and strengthening of RC structures has become a major problem for civil
engineers in the past few decades. To satisfy this problem, a previous method for the repair and
strengthening of RC beams included bonding steel plates to the inferior structure. However, bonding steel
plates to concrete presents disadvantages, including corrosion of the steel/adhesive joints and the heavy
weight of the material. These problems increase installation and maintenance costs. The bonding of Fiber
Reinforced Plastics (FRP) to structures provides an attractive alternative to steel plates. This material
is corrosion resistant and lightweight, has a high strength-to-weight ratio and possesses nonconductive
properties. The use of Fiber Reinforced Plastics (FRP) in repairing and strengthening RC beams has been
researched in recent years. In particular, attaching unidirectional FRP to the tension face of RC beams has
provided an increase in the sti ness and load capacity of the structure. However, due to the brittle nature
of unidirectional FRP, the ductility of the beam decreases. Consequently, the safety of the structure is
compromised, due to the reduction in ductility. The purpose of this research is to investigate the behavior
of high strength reinforced concrete beams strengthened with FRP sheets. The major test variables included
the di erent layouts of CFRP sheets and the tensile reinforcement ratio. More particularly, change in the
strength and ductility of the beams, as the number of FRP layers and tensile reinforcement bar ratios are
altered, is investigated. Eight under-reinforced concrete beams were fabricated and tested to failure. With
the exception of the control beam, one or four layers of CFRP were applied to the specimens.https://scientiairanica.sharif.edu/article_3189_df4749d75c1876666611aff36979e78f.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Long Lead Rainfall Prediction Using Statistical Downscaling and Arti cial Neural Network Modeling3190ENS.NazifDepartment of Civil Engineering,University of TehranM.KaramouzDepartment of Civil and Environmental Engineering,Amirkabir University of TechnologyM.FallahiDepartment of Civil Engineering,Amirkabir University of TechnologyM.Rahimi FarahaniDepartment of Civil Engineering,Amirkabir University of TechnologyJournal Article20090606Abstract. Long lead rainfall prediction is important in the management and operation of water
resources and many models have been developed for this purpose. Each of the developed models has
its special strengths and weaknesses that must be considered in real time applications. In this paper, eld
and General Circulation Models (GCM) data are used with the Statistical Downscaling Model (SDSM)
and the Arti cial Neural Network (ANN) model for long lead rainfall prediction. These models have been
used for the prediction of rainfall for 5 months (from December to April) in a study area in the south
eastern part of Iran. The SDSM model considers climate change scenarios using the selected climate
parameters in rainfall prediction, but the ANN models are driven by observed data and do not consider
physical relations between variables. The results show that SDSM outperforms the ANN model.https://scientiairanica.sharif.edu/article_3190_ffc4462369f8e85c72ce9992bb5a9242.pdfSharif University of TechnologyScientia Iranica1026-309816220090401Graph Theoretical Topology Control in Structural Optimization of Frames with Bracing Systems3191ENA.KavehDepartment of Civil Engineering,Iran University of Science and TechnologyM.ShahrouziDepartment of Engineering,Building and Housing Research CenterJournal Article20090606Abstract. Many topological objectives and constraints can not easily be assessed by analytical
formulations. This paper introduces a number of graph theoretical operators, as suitable combinatorial
tools, for discrete topology assessment. Using such an approach, the load paths from their exertion points
to the support joints can be guided topologically during the optimization process. Eleven variants of the
proposed method are developed for the inclusion of various constraints and/or objectives. The presented
algorithms are then applied to the optimal bracing layout of multi-story frames under lateral loadings
for minimal weight or static compliance. Benchmark examples from literature are treated to validate the
eciency and to compare the capability of the proposed algorithms. The bracing patterns obtained from
optimization are graph theoretically categorized.https://scientiairanica.sharif.edu/article_3191_07299341c5319eeef5494400d18ce98c.pdf