eng
PenPub
Journal of Civil Engineering and Materials Application
2676-332X
2588-2880
2019-12-01
3
4
183
192
10.22034/jcema.2019.99690
99690
Original Article
Seismic Behavior of Steel-Concrete Composite Columns Under Cyclic Lateral Loading
Alireza Behnamnia
1
Maryam Barati
2
Department of civil engineering, college of engineering, kermanshah branch, Islamic azad university, Kermanshah, Iran.
Department of civil engineering, college of engineering, sanandaj branch, Islamic azad university, Sanandaj, Iran.
Lightweight concrete has been used in the construction industry for many years and by the introduction of modern technologies in the construction industry, this type of concrete has been accounted as one of the powerful and reliable materials in the construction industry. The density of lightweight concrete is about 0.56 that of the ordinary concrete. This type of concrete is commonly used as a flooring material in buildings. Thus there is possibility of its corrosion in different climatic conditions. In the present research, we would investigate the compressive strength and durability of the lightweight concrete in the acid environment, so that by specifying the corrosion rate, one could have a better understanding of the behavior of these concretes. For making the lightweight concrete in the present research use has been made of pumice aggregate in the mix design, and the acid used is 1M sulfuric acid. Also, the effect of adding two types of Nanomaterials i.e., Nano silica and Nano clay on the concrete behavior is assessed. The results have shown that in case of keeping the specimens of lightweight concrete in the acid environment for 90 days, their weight reaches 0.56 that of the ordinary specimens. The results of the current research have shown that the use of Nano silica and Nano lime per 10 wt% of cement could result in the increased compressive strength of the lightweight concrete. So that the concrete compressive strength per 10 wt% of Nano lime increases by 1.43%. On the other hand, the concrete durability in the acid solutions reaches the maximum value per addition of 5% Nano silica and 5% Nano lime, and has lost a lower percentage of its weight.
https://www.jcema.com/article_99690_0d282af9e8757539cfc262461ffaf8a0.pdf
Composite Column
thickness of steel layer
cyclic lateral loading
eng
PenPub
Journal of Civil Engineering and Materials Application
2676-332X
2588-2880
2019-12-01
3
4
193
201
10.22034/jcema.2020.101232
101232
Original Article
Effect of Hybrid Fibers on Water absorption and Mechanical Strengths of Geopolymer Concrete based on Blast Furnace Slag
Amir Bahador Moradikhou
1
Alireza Esparham
2
Mohammad Jamshidi Avanaki
moh.jamshidi@ut.ac.ir
3
Young Researchers and Elites club, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Young Researchers and Elites club, Science and Research Branch, Islamic Azad University, Tehran, Iran.
School of Civil Engineering, College of Engineering, University of Tehran, 14155-6457, Tehran, Iran.
In recent years, geopolymers, as a new class of green cement binders, have gained significant attention as an environmental-friendly alternative to Ordinary Portland Cement (OPC) which can potentially reduce negative environmental impacts of OPC. Fiber Reinforced Geopolymer Concrete (FRGPC) is known as a new type of concrete with enhanced ductility characteristics over conventional concrete. In this experimental study, hybrid fibers of 12mm modified polypropylene and 55mm polyolefin were used to manufacture FRGPC specimens based on Granulated Ground Blast Furnace Slag (GGBFS). In this regard, FRGPC and non-fiber specimens were produced. The specimens were subjected to compressive, indirect tensile and 3-point flexural tests, as well as water absorption capacity and specific density studies. The obtained results showed that using hybrid fibers decreased the specific density and water absorption, a slight increase in compressive strength and a significant improvement in tensile and flexural strengths of FRGPC specimens compared to non-fiber specimens.
https://www.jcema.com/article_101232_c2e2fc3e82636c09724411cbcc387327.pdf
Fiber Reinforced Geopolymer Concrete
Hybrid fibers
Compressive strength
tensile strength
Flexural Strength
eng
PenPub
Journal of Civil Engineering and Materials Application
2676-332X
2588-2880
2019-12-01
3
4
203
213
10.22034/jcema.2019.101787
101787
Original Article
Studying the Buckling Behavior of Composite Columns (CFST) by Cyclic Loading
Seyed Ali Mousavi Davoudi
ali_mousavii@yahoo.com
1
Morteza Naghipour
2
Department of Structural Engineering, Faculty of Engineering and Civil Engineering, Tabari Higher Education Center, Babol, Iran.
Faculty of Engineering, Noshirvani University of Technology, Babol, Iran.
One of the most sensitive decisions a structural designer should consider is choosing the type of consumables in the structure. This decision is in many cases dependent on the type of structure, financial issues also the experience and skill of the designer. The main aim pursued in the design is to obtain highly secure, economical structures. Concrete and steel are materials that are widely used in construction. The benefits of both materials are well known today. The clever combination of these two materials, an effective explosion-proof system, will have the effect of exploding explosions in the Plasco building in Tehran compared to using any of the materials. Lack of efficient performance factors, lack of clear and valid guidelines for the seismic design of such columns, how to model their geometry and material can still be obstacles to using such systems. In this research, according to the objectives of the problem, different parameters should be evaluated, this parameter is the type of column cross-section geometry. The aim is to determine the effect of defined parameters, especially column geometry, on the behavior and seismic capacity of composite columns) CFST(, achieving high resistivity, especially for columns that, incidentally, increase their loading exponentially with increasing classes. It is found that circular sections of composite columns )CFST( show better behavior and performance than columns with square geometry and further show that composite columns) CFST( can be used as a basic solution. Use it to solve challenges between designers and architects.
https://www.jcema.com/article_101787_8958f306698dd2db0ec2eda05bfcab24.pdf
CFST Column
Seismic Load
Nonlinear Analysis (NSP)
finite element analysis
eng
PenPub
Journal of Civil Engineering and Materials Application
2676-332X
2588-2880
2019-12-01
3
4
215
223
10.22034/jcema.2020.102699
102699
Original Article
In Vitro Evaluation of the Effect of SP200 Lubricant on Compressive Strength of Lightweight Concrete with Leca Aggregate and Powdered Silica
Neda Mohammadi
1
Davood Ghaedian Ronizi
ghaedian@ut.ac.ir
2
Building Materials Institute, Apadana Institute of Higher Education, Shiraz, Iran.
Department of Civil Engineering, Eghlid Branch, Islamic Azad University, Shiraz, Iran.
In today's advanced world and due to advances in various scientific fields of the concrete, industry has also evolved, and light concrete production is a result of these advances. It has had its advantages, many efforts have been made in the past to improve the quality and efficiency of concrete, and today the use of additives helps us to achieve this goal. The additive in this study is lubricant based on polycarboxylate brand SP200 and Powdered silica. The use of silica is also widely used in advanced countries due to its pozzolanic properties. In this study of 20 mixing designs, 2 of which were used as control sample and 18 with SP200 super-lubricant and micro silica powder, the results show that in the first mixing design with 0.49 water/cement ratio the highest compressive strength of The 7 and 28 days is related to M / 35/5 sample which has 0.35% super-lubricant and 5% micro silica powder And in the second mixing scheme with water/cement ratio of 0.55, the highest compressive strength is related to the sample of M /35/10 It contains 0.35% super-lubricant and 10% Powdered silica. The use of silica and super-lubricant in the manufacture of lightweight concrete has increased the compressive strength of lightweight concrete in some of the samples.
https://www.jcema.com/article_102699_91a7c1250a24474ed4cfb6cb68aafed0.pdf
Structural lightweight concrete
Leca Industrial shell
Powdered silica
Super lubricant
eng
PenPub
Journal of Civil Engineering and Materials Application
2676-332X
2588-2880
2019-12-01
3
4
225
233
10.22034/jcema.2019.102829
102829
Original Article
An Analysis of the Shear Strength and Rupture Modulus of Polyolefin-Fiber Reinforced Concrete at Different Temperatures
Moslem Yousefvand
m.yousefvand.vru@gmail.com
1
Yaser Sharifi
2
Saeed Yousefvand
3
Department of Structural Engineering, Vali Asr University, Rafsanjan, Iran.
Department of Civil Engineering, Vali Asr University, Rafsanjan, Iran.
Department of Structural Engineering, Malayer University, Malayer, Iran.
Structural engineers are generally aware of the intrinsic safety properties of concrete exposed to fire (non-flammability at high temperatures). However, the tendency of concrete for spalling at high temperatures is a significant defect, and recently many researchers have conducted studies on this issue. One of the primary objectives of this study is to assess the shear strength and modulus of rupture of concrete reinforced with different percentages of modified polyolefin synthetic fibers at different temperatures and to compare the results with the preliminary design. The other objective of the present study is to compare the behaviors of synthetic fiber concrete under the effect of the furnace temperature and direct fire. After adding fibers (1.5 volumetric percentage), a 29% increase in the tensile strength and a 56% increase in the modulus of rupture (the stress corresponding to the development of the first crack) were observed. Considering the fiber concrete results in the experimental temperature condition, it can put on an acceptable strength performance. However, at temperatures equal to or greater than 400 , the fibers lose their role in compensating the low tensile strength of concrete due to oxidation, causing porosity in the concrete and reducing its strength.
https://www.jcema.com/article_102829_8ba0d65b3a47bdf6db36a029b3107077.pdf
fiber-reinforced concrete
tensile strength
rupture modulus
high temperature