In this research, efforts were made to study the effects of water to cement ratio (W/C) and steel fiber volume fraction (V_f (%)) on the fracture parameters of self-compacting steel fiber-reinforced concrete using both Work Fracture and Size Effect Methods. In an experimental program, a variety of water to cement ratio and volume of steel fibers were considered and five mix...
Investment in construction industry is facing with many uncertainties. So, mass housing and its financing has been mostly performed by public sector. One of the mechanisms to finance in mass housing is the partnership of public-private that for its realization many challenges and obstacles have to be removed. Therefore, the research has been performed to the aim of study and...
In this paper, the structural behaviour of precast concrete sandwich panels (PCSP) under flexure is studied. Finite element analyses (FEA) were carried out to study the behavior of composite precast concrete sandwich panels (PCSP) in order to examine feasibility of their usage as slab elements in the construction industry. The panels are composed of three layers; A high strength...
Consecutive loads can be a serious threat to the safety of structures. Abrupt removal of elemental elements such as columns is one of the causes of progressive failure in structures. The local breakdown caused by the sudden removal of the column can affect the behavior of the structures of successive courts. One of the loads that threatens the safety of the structure over the...
ABSTRACTA new kind of double skin CFT has more benefits in construction of bridge and especial buildings due to easily multi beam connections for central columns. In this study 27 double skin specimens filled with concrete, consist of internal circular tube and external hexagonal tubes have been studied using ABAQUSE finite element software. The effects of some parameters on...
The tuned mass damper is one of the latest structural control system that helps the structure to damp the dynamics loads. So far using the Tuned Mass Damper (TMD) on the roof or a few dampers was installed at several points at the height of the building or other levels of the building was popular, but this system has some disadvantages like considering a significant mass as...
In the present study, the use of buckling-restrained braces (BRBs) has been evaluated as a research innovation aimed at reducing the potential of progressive collapse in steel braced frames. These braces prevent the overall buckling of brace and provide much more energy absorption than conventional convertible bracing systems. For this purpose, three-dimensional finite element...
The use of porous concrete system in urban areas as a modern and applied management approach during rainfall can prevent the problems by rapid outflow of the surface runoff. In this research, effect of replacing dolomite minerals in two modes of fine-grained and powder, as part of the aggregates or part of the cement, respectively, is investigated on the structural properties of...
Reactive powder concrete (RPC) is one of the ultra high performance concrete ( UHPC ) with superior physical and mechanical properties . Reactive powder concrete is produced using cement and very fine powdered materials including crushed quartz , silica fume and low water to cement ratio using super plasticizer . In this study , an optimum mixing ratio of RPC has been used , in...
One of the factors of damage and destruction of concrete structures is fire. Concrete structures, in addition to having the proper mechanical characteristics, they must have durability properties to use their capacity over their lifetime. In this study, the effect of various volume fraction of steel fibers on improving the mechanical and durability properties of concrete at...
Production of Portland Cement (PC) is a highly energy-intensive process and causes significant environmental damages. Thus scientists are always after ways to reduce these negative effects and find a more efficient process of producing cement. Geopolymers are amongst materials that are used as a substitute for cement in concrete. Geopolymer consists of one or more source...
Severe damages of structures during large earthquakes and the loss of national wealth has made it extremely important to reduce the vibrations of structures against wind and earthquake. One of the efficient ways to reduce these vibrations, is to use the tuned liquid damper (TLD). The tuned liquid damper is the passive control system of the structure, which is made up of several...
Subsurface characterization has always been an interesting issue in Geotechnical and geological engineering, especially when there is a potential risk of subsurface anomalies such as cavities and sinkholes. Due to the low resolution and accuracy of seismic recorded data at higher depths, anomalies identification has become more difficult. In this paper, the effect of various...
The present study deals with dynamic analysis of steel chimney taking rotational components of earthquake into account. The translational components of the earthquake have been used in order to obtain the rotational components of the earthquake, based on the intersecting isotropic elastic wave propagation. For this purpose, a transitional component of ground motion using...
The earthquake is one of the natural hazards that have caused many casualties and financial losses throughout the world over the years. This has been the reason why the earthquake hazard analysis studies should be studied more seriously. Iran is also located in one of the seismically active regions of the world, the Himalayan- Alpine belt, which experiences many earthquakes every...
Observations from past earthquakes in reinforced concrete buildings show that the masonry partitions can endanger the life of buildings occupants and lead to significant damage and loss. The most present codes of practice do not consider the effects of nonlinearity and higher modes of the structure and three-dimensional behavior of partitions on the out-of-plane seismic demands...
Using viscoelastic (VE) dampers is one of the most effective tools for seismic retrofitting of steel structures. The results of many experimental studies demonstrated that using fractional derivative terms for modelling viscoelastic dampers offers an acceptable level of accuracy. Unlike viscous dampers the damping force is not linearly dependent to velocity and it is also highly...
Nowadays, nonlinear static and dynamic analyses methods are rapidly expanding to evaluate the seismic performance of structures. Nonlinear dynamic analyses methods require a large amount of computations and are relatively time consuming. This fact has led to the emergence of novel methods based on the concepts of nonlinear static and dynamic analyses. One of the most widely used...
In this paper, factors affecting the mechanical properties of polymeric granite artificial stone have been investigated. Epoxy resin and three types of additives called Poly ether ether ketone, Silicon rubber, and Nanoclay have been used to make the artificial stone. Unlike previous research on resin alone, this study has been conducted on artificial stone and samples made using...
Assessment and investigation of soil and bedrock properties is of an essence for construction of residential, commercial as well as industrial complexes. In order for the foundation system of such projects to be opted, it is necessary to assess the geotechnical characteristics of the site. In many projects where the site is located on problematic soils or non-engineered fills, if...
زلزله یکی از آشناترین پدیده های طبیعی است که به دلیل عدم امکان پیش بینی زمان وقوع و پیشگیری از زمین لرزه به دنبال خود خسارات جانی و مالی بسیاری را به همراه دارد و ایران با ساختار ویژه لرزهزمین ساخت، وجود گسلهای فعال و لرزهخیزی زیاد در زمره مناطق با خطر بالای زلزله در جهان قرار دارد. یکی از ابزارهای کنترل رفتار سازه استفاده از میراکننده ها است. میراگرهای تسلیمی برای مستهلک کردن...
Hollow structural sections (HSS) have been used in many structural applications, owing to their efficient structural performance and suitable appearance. However, due to the lack of access inside the HSS column for bolting purposes, it has been difficult to develop a practical bolted moment connection. Thus, field welded beam-to-HSS column connections have been the only viable...
The nature of dynamic loading is different due to the high force in a few milliseconds with static loading. The amount of energy absorption and energy loss in composite materials is a suitable measurement to evaluate the performance against impact loads. On the other hand, the use of self-compacting composites due to its unique properties has attracted the attention of...
The linked column frame (LCF) as a seismic resistant system with the ductile behavior using shear fuse will reduce the damage to other members of the structure at different hazard levels. In this paper, the seismic behavior of the LCF systems designed by Shoaib and Malakoutian procedures has been evaluated. In order to improve the seismic performance of the designed samples, a...
Today, it is quite clear that the speed of development of infrastructure in developing countries has led to much damage to the environment. Concrete is one of the products that plays an important role in the use of non-renewable resources. Today, the vision of sustainable development in the manufacturing industry is growing and increasing, and concrete is at the forefront of this...