Strengthening of Heat Damaged Reinforced Concrete Short Columns

2014 ◽  
Vol 5 (4) ◽  
pp. 381-398 ◽  
Author(s):  
A. Roy ◽  
U. Sharma ◽  
P. Bhargava
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Axial Stress ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Stress Strain ◽  
Heating And Cooling ◽  
Short Columns ◽  
Glass Fiber Reinforced

The purpose of this study was to investigate the effectiveness of different strengthening schemes in strengthening heat damaged reinforced concrete short columns. A series of 63 heat damaged specimens were tested under concentric compression after jacketing externally with High Strength Fiber Reinforced Concrete (HSFRC), Ferrocement (FC) and Glass Fiber Reinforced Polymer (GFRP) jackets. The specimens were subjected to various heating and cooling regimes. The overall response of strengthened specimens was investigated with reference to un-strengthened specimens in terms of axial compressive strength, ductility, lateral stress-strain, and axial stress-strain behaviour. It was observed that while the GFRP jacketing is quite effective in improving compressive strength and energy dissipation, it is not capable of improving stiffness. On the contrary FC and HSFRC jacketing were mainly effective in improving stiffness property. Overall GFRP jacketing was found to be the most effective method of strengthening fire or heat damaged concrete columns.

scholarly journals Effect of size and shape of specimen on compressive strength of glass fiber reinforced concrete (GFRC)

2011 ◽  
Vol 9 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Rao Krishna ◽  
Rathish Kumar ◽  
B. Srinivas
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Glass Fiber ◽  
High Strength Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Strength Concrete ◽  
Size And Shape ◽  
Glass Fiber Reinforced ◽  
Compressive Strength Of Concrete

Concrete is a versatile material with tremendous applications in civil engineering construction. Structural concrete elements are generally made with concrete having a compressive strength of 20 to 35 MPa. Lately, there is an increase in use of high strength concrete (HSC) in major construction projects such as high-rise buildings, and bridges involving members of different sizes and shapes. The compressive strength of concrete is used as the most basic and important material property in the design of reinforced concrete structures. It has become a problem to use this value as the control specimen sizes and shapes are different from country to country. In India, the characteristic compressive strength is usually measured based on 150 mm cubes [1]. But, the ACI code of practice specifies the design compressive strength based on the standard 150x300 mm cylinders [2]. The use of 100x200 mm cylinders gained more acceptance as the need to test high strength concrete increases [3]. In this context the size and shape of concrete becomes an important parameter for the compressive strength. In view of the significance of compressive strength of concrete and due to the fact that the structural elements of different sizes and shapes are used, it is proposed to investigate the effect of size and shape of the specimen on the compressive strength of concrete. In this work, specimens of plain as well as Glass Fiber Reinforced Concrete (GFRC) specimens are cast in order to carry out a comparative study.

Mechanical Properties of Fiber Reinforced Concrete

2018 ◽  
Vol 875 ◽  
pp. 174-178
Author(s):  
Bhawat Chaichannawatik ◽  
Athasit Sirisonthi ◽  
Qudeer Hussain ◽  
Panuwat Joyklad
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Glass Fiber ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Sisal Fiber ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced

This study presents results of an experimental investigation conducted to investigate the mechanical properties of sisal and glass fiber reinforced concrete. Four basic concrete mixes were considered: 1) Plain concrete (PC) containing ordinary natural aggregates without any fibers, 2) sisal fiber reinforced concrete (SFRC), 3) sisal and glass fiber reinforced concrete (SGFRC), 4, glass fiber reinforced concrete (GFRC). Investigated properties were compressive strength, splitting tensile strength, flexural tensile strength and workability. The results of fiber reinforced concrete mixes were compared with plain concrete to investigate the effect of fibers on the mechanical properties of fiber reinforced concrete. It was determined that addition of different kinds of fibers (natural and synthetic) is very useful to produce concrete. The addition of fibers was resulted into higher compressive strength, splitting and tensile strength. However, the workability of the fiber reinforced concrete was found lower than the plain concrete due to the addition of fibers in the concrete.

The effects of fibers on the confinement models for concrete columns

2002 ◽  
Vol 29 (5) ◽  
pp. 742-750 ◽  
Author(s):  
Giuseppe Campione
Keyword(s):  
Reinforced Concrete ◽  
High Strength Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Stress Strain ◽  
Concrete Core ◽  
Strength Concrete ◽  
Transverse Steel

A mathematical model is developed to express the stress–strain relationships in compression of fiber-reinforced concrete (FRC) columns for both normal- and high-strength concrete, with and without conventional steel reinforcement. This model allows one to determine the maximum strength and strain capacity by determining the effective concrete core of the confining devices at rupture. Analytical expressions are also given for the ultimate load corresponding to the complete formation of the concrete failure plane. The proposed model incorporates the most relevant parameters of confinement, i.e., type of confinement, volumetric ratio, spacing, yielding strength, shape of the member cross section, type of fiber (length, diameter, shape), and fiber volume. The model has been verified against data obtained from concentric compressive tests on concrete specimens reinforced with transverse steel and fibers.Key words: high-strength concrete, fiber-reinforced concrete, lateral reinforcement, stress–strain curves.

scholarly journals Durability and Physical Properties of Glass Fiber Reinforced Concrete Subjected to Elevated Temperatures

2019 ◽  
Vol 8 (11) ◽  
pp. 3845-3848
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Glass Fiber ◽  
Elevated Temperatures ◽  
Glass Fibers ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced ◽  
The Matrix

Addition of glass fibers into concrete significantly modifies its tensile strength. The fibers are placed at desired locations and orientations by the matrix surrounding it, thereby making the fibers as principal load carrying members and also protecting them from environmental damage. Glass fibers provide resistance to high temperature, and the ease of incorporating them into the matrix either in continuous or discontinuous lengths. In this work, carbonation test representing the durability of Glass Fiber Reinforced Concrete (GFRC) was carried out, and then experimental program determines the properties like compressive strength, split tensile strength and flexural strength of GFRC for 7 days and 28 days of curing, with percentage of fibers in ratios 0.5%, 1%, 1.5%, 2% and performance of GFRC at elevated temperatures of 300°c, 500°c, 700°c, 1000°c are compared with conventional concrete. The results depict that, the residual compressive strength capacity of GFRC is greater than unreinforced concrete both at elevated and normal temperatures.

Mechanical Properties of Hybrid Nylon-Steel- and Steel-Fibre-Reinforced High Strength Concrete at Low Fibre Volume Fraction

2010 ◽  
Vol 168-170 ◽  
pp. 1704-1707 ◽  
Author(s):  
Ming Kun Yew ◽  
Othman Ismail
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Strength Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete

The mechanical properties of hybrid nylon-steel-fiber-reinforced concrete were investigated in comparison to that of the steel-fiber-reinforced concrete, at the same volume fraction (0.5%). The combining of fibers, often called hybridization is investigated in this paper for a very high strength concrete of an average compressive strength of 105 MPa. Test results showed that fibers when used in a hybrid nylon-steel fibers reinforced concrete form could result in superior composite performance compared to steel-fiber-reinforced concrete. The basic property of the hybridized material that was evaluated and analyzed extensively was the modulus of rupture (MOR) and splitting tensile while the compressive strength was only slightly decreased compared to single steel fiber reinforced concrete. There is a synergy effect in the hybrid fibers system.

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