Normal and high strength concrete

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Effects of GFF bands on normal and high strength concrete cylinders

Effects of GFF bands on normal and high strength concrete cylinders

This paper exemplifies the effects of externally confined Glass Fibre Fabric (GFF) bands on normal and high strength concrete cylinders. Twelve normal and high strength concrete cylinders were cast and tested in the laboratory environment under axial compression to failure. The experimental results show that the degree of confinement of discrete GFF confined high strength concrete cylinders was significantly better than normal strength concrete cylinders with GFF bands, however the ductility of GFF confined high strength concrete cylinders was relatively less than GFF normal strength concrete. It was also found that the application of horizontally oriented GFF bands is the most effective confining pattern than spirally oriented GFF bands.
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Effects of GFF Bands on Normal and High Strength Concrete Cylinders

Effects of GFF Bands on Normal and High Strength Concrete Cylinders

This paper exemplifies the effects of externally confined Glass Fibre Fabric (GFF) bands on normal and high strength concrete cylinders. Twelve normal and high strength concrete cylinders were cast and tested in the laboratory environment under axial compression to failure. The experimental results show that the degree of confinement of discrete GFF confined high strength concrete cylinders was significantly better than normal strength concrete cylinders with GFF bands, however the ductility of GFF confined high strength concrete cylinders was relatively less than GFF normal strength concrete. It was also found that the application of horizontally oriented GFF bands is the most effective confining pattern than spirally oriented GFF bands.
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EFFECT OF NATURAL RUBBER LATEX ON NORMAL AND HIGH STRENGTH CONCRETE

EFFECT OF NATURAL RUBBER LATEX ON NORMAL AND HIGH STRENGTH CONCRETE

Nowadays the concrete properties are upgraded regarding the fresh and hardened properties by inclusion of new material other than ingredients of concrete, from reducing porosity by compaction, improves the strength of the concrete. In order to increase the usage of latex modified concrete, greater understand about natural rubber latex modified concrete with locally available materials such as cement, fine aggregate, coarse aggregate is essential. This paper illustrates the effect of natural rubber latex addition to the concrete in small increment in the strength. Also the material available locally is also encourages to investigate the properties of natural rubber latex modified concrete. Natural rubber latex is added in small percentages for both normal strength concrete and high strength concrete. In the normal strength concrete, natural rubber latex effect is linearly increases for the particular percentage that is up to the 0.9%. Mechanical strength of the normal strength concrete such as compression, split tensile, flexural strengths were increases there after decreases at 0.9%. Natural rubber latex of same percentage which is added to the normal strength concrete is added to the high strength concrete, here the Natural Rubber Latex effect is not linear as in the normal strength concrete, it increase the strength of both flexure and split tensile as the percentage of natural rubber latex increases but compression strength is observed to increase at 0.3% and then decrement in further addition.
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Comparative Analysis of High Strength Concrete and Normal Strength Concrete Columns Exposed to Fire

Comparative Analysis of High Strength Concrete and Normal Strength Concrete Columns Exposed to Fire

Abstract - The increased usage of high strength concrete in buildings has resulted in concern regarding the behavior of such concrete under fire. In particular, spalling at certain temperatures, as identified by performing a fire test on concrete columns in laboratories, is of particular concern. This paper provides comparative analysis of structural behavior and the principal influences of high temperature in concrete at loss of compressive strength and spalling, the unintended discharge of material from a member of high strength concrete (HSC) column and normal strength concrete (NSC) columns. Though a lot of information has been gathered on both phenomena, there remains a need for a broader understanding of the response of concrete structures to different heating rates and the performance of complete concrete structures subjected to realistic fire exposures. There is a lack of information derived from large-scale tests on concrete buildings in natural fires. So we are experimenting fire test on Four Reinforced (normal strength and higher strength) concrete columns in laboratory to get actual behavior of concrete columns.
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Experimental Study on Development of Normal Strength Concrete and High Strength Concrete Using Alccofine

Experimental Study on Development of Normal Strength Concrete and High Strength Concrete Using Alccofine

strength in concrete. The experimental work is carried out to evaluate mechanical properties such as compressive strength, split tensile strength and flexural strength for normal strength concrete and high strength concrete. Normal concrete and High strength concrete is made by replacing alccofine by weight of cement various percentage 0% ,9%, 10% , 11% ,12% ,13%, 14%.using constant water cement ratio 0.45and 0.30 for M30 and M70 concrete respectively, super plasticizer are used for required degree of workability. Casting specimen is cured in atmospheric temperature and hardened properties for 7, 14 and 28days
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Behaviour of Normal Strength concrete and High Strength concrete subjected to In-plane Shear

Behaviour of Normal Strength concrete and High Strength concrete subjected to In-plane Shear

The principal objectives of this study was to investigate the shear capacity of Normal Strength Concrete (NSC) and High Strength Concrete(HSC) at different inclination of shear plane using push-off test specimen. The grades of concrete used are M30 for NSC and M70 for HSC. Dimension of push-off specimen chosen was 150x150x260mm with two notches of 10mm thick with varying length 75mm, 65mm, 55mm and 45mm to induce shear plane inclination of 0°, 11°, 22°, 31° respectively. Notches were 100mm apart perpendicular to the axis of loading on specimen and equidistance from the mid height of shear plane. Plain push-off specimen and End-Block strengthened push-off specimens were used to study influence of induced compressive stress normal to the shear plane on shear strength. It was observed from the experimental results as the inclination increased, the in-plane shear stress increased
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A Study on Fracture Parameters of Normal and Self-Compacting Concrete and High-Strength Concrete Using Normal and Recycled Aggregates

A Study on Fracture Parameters of Normal and Self-Compacting Concrete and High-Strength Concrete Using Normal and Recycled Aggregates

ABSTRACT: The recycling of Construction and Demolition Wastes has long been accepted to have the possible to conserve natural resources and to decrease energy used in production. In some nations it is a standard substitute for both construction and maintenance, particularly where there is a scarcity of construction aggregate. The use of recycled aggregate weakens the quality of recycled aggregate concrete which limits its application. Concrete recycling gains importance because it protects natural resources and eliminates the need for disposal by using the readily available concrete as an aggregate source for new concrete or other applications. The quality of concrete with recycled aggregate concrete (RAC) is very dependent on the quality of the recycled material used.
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BLIND BLAST SIMULATION: A VALIDATION EFFORT ASSESSMENT

BLIND BLAST SIMULATION: A VALIDATION EFFORT ASSESSMENT

As part of the “Blind Blast Simulation Contest 1 ,” organized by the University of Missouri Kansas City, participants were invited to submit predictions of reinforced concrete slabs subjected to air blast loading. There were two classes of concrete: normal strength f c ′ = 5 ksi (34.5MPa) and high strength f c ′ = 15 ksi (103.5MPa). The normal strength concrete was reinforced with Number 3 Grade 60 steel bars with yield strength of 68ksi (469MPa). The high strength concrete was reinforced with Vanadium Number 3 bars with nominal yield strength of about 83ksi (572MPa). Each concrete slab design was subjected to two different air blast pulses with impulses of about 5.38 and 7.04 MPa-ms.
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Ultra High Strength Concrete

Ultra High Strength Concrete

Ordinary Portland cement (OPC) - The cement used during the experiments is Ordinary Portland Cement of Grade 53 conforming to IS 12269:1987. According to IS 4031 the tested 28-day mortar compressive strength is 58MPa. The specific gravity is 3.15; the initial is35 minutes. The normal consistency being 30% and the particle size range lies between 31µm to 7.5µm.

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A Study on Properties of Self Curing Concrete using Polyethylene Glycol 400

A Study on Properties of Self Curing Concrete using Polyethylene Glycol 400

It can become a new practice in construction field of replacing conventional concrete with internally cured concrete to skip curing process. It can be used for normal as well as high strength concrete. More of research can be done such as self-compacted internally cured concrete. Research on internally cured concrete in hot and cold weather condition can be done. Many other properties of concrete can also be studied such as chemical and physical properties.

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INCLUSION OF COIR FIBER IN HIGH STRENGTH CONCRETE BLENDED WITH SILICA FUME

INCLUSION OF COIR FIBER IN HIGH STRENGTH CONCRETE BLENDED WITH SILICA FUME

During past few years, need of high strength concrete has been increased than the normal strength concrete (NSC), because of growth in population and industrial area. To fulfill the requirements of increased population and the needs of developing industrial areas, construction of multi-storied buildings and high rise buildings is the only way for civil and structural engineers. Now a days usage of high strength concrete increased to have more durable and high stiffness buildings. So many researchers are inventing various new types of concrete composites in the laboratories by utilizing the waste industrial byproducts, domestic wastes and agricultural wastes etc; for the partial replacement of conventional construction materials, to make the concrete composite such as eco friendly, cost effective, durable and high strength. In high strength concrete mixes water- cement ratio is very low and cement content is high. This increase in cement content leads to the high emissions of CO 2
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Strength Analysis   Building Frame with Polyurethane Cement Composite (PUC)

Strength Analysis Building Frame with Polyurethane Cement Composite (PUC)

In the study presented by V.S. Sethuraman, K.Suguna, and P.N. Raghunath “ Numerical Analysis of High Strength Concrete Beams using ABAQUS”. The objective of this paper is to model and analyses an M60 concrete Beam using Abaqus for static load and verify the same using experiment. In recent years, Concrete having a compressive strength of 60 MPa and above is being used for high-rise buildings and long span bridges. ABAQUS is a suite of powerful engineering simulation programs, based on the finite element method (FEM) that can solve problems ranging from relatively simple linear analyses to the most challenging nonlinear simulations. The advent of newer concrete making technologies has given impetus for making concrete of higher strength. As per our Indian standard IS 456: 2000 concretes are grouped as ordinary concrete, standard concrete and high strength concrete as given in Table 4.1. The code did not describe about UHSC, but the American Concrete Institute (ACI) categories the concrete as Normal Strength Concrete (NSC), High Strength Concrete (HSC) and Ultra High Strength Concrete. [21]
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Strength Studies on Different Grades of Concrete Considering Fire Exposure

Strength Studies on Different Grades of Concrete Considering Fire Exposure

temperatures on compressive strength of high strength concrete under both unloaded and preloaded conditions and to compare the behaviour with that of normal strength concrete. Based on the results obtained in the study it was concluded that when exposed to temperatures in the range of 100 to 300°C. [6] Performed fire tests on slab specimens with high strength concrete with and without silica fume and normal strength concrete and concluded that fire endurances of all five specimens were not significantly different. [7] Concrete specimens were heated in a muffle furnace to varying temperatures up to 800°C and the changes in the compressive strength, ultrasonic pulse velocity and rebound number were determined. The residual compressive strength for high strength concrete with blended cement after heating to 800°C and water quenched, were 31% of its initial strength whereas they corresponding residual strength for concrete with ordinary Portland cement was 44%. [6] Conducted research to study the effect of elevated temperature effects on high Strength Concrete residual strength. They concluded that there appeared to be a slight improvement in residual strength at 200°C exposure than when it is subjected to 100°C exposures. At constant temperatures of 300°C there is a significant loss of strength. At temperatures 900°C and after, all the concretes essentially had no structural integrity. Residual strengths of HSC at exposed temperatures of 300°C or higher are significantly different than residual strengths for NSC. [14] Experimentally investigated and proved that adding of Nano silica with cement helps in improving strength and durability properties of concrete. In his studies nano silica is added to concrete with different replacements (1%, 1.5% and 2%) and found out strength and few durability properties and concluded nano silica with 1.5% is optimum. [15] Their studies on usage of paper industry waste in concrete was tested as an alternative to traditional concrete. The cement has been replaced by paper industry waste in different replacement levels like 0%, 10%, 20%, and 30% by weight for M-25 grade of concrete and found out strength properties. Also concluded that compressive strength was improved with 30% replacement of cement. [16] In their studies, they provides a summary of findings on the fire response of fibre. Namely, the information on steel fibre reinforced concrete (SFRC), synthetic fibre reinforced concrete and hybrid (steel + synthetic) fibre reinforced concrete have been gathered from various contributions published up to date. The mechanical properties including the melting point and ignition point of fibres affect significantly the properties of concrete composites with addition of fibres.
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Ultimate Tendon Stress in CFRP Strengthened Unbounded HSC Post-Tensioned Continuous I-Beams

Ultimate Tendon Stress in CFRP Strengthened Unbounded HSC Post-Tensioned Continuous I-Beams

loading is difficult. In the case of post- tensioned members hundreds of elements, both slabs and beams cast with normal strength concrete were tested by Warwaruk et al. [1]; Cooke et al [2]; Elzatany and Nilson [3]; Du and Tao [4]; Chouinard [5]; Harajli and Kanj [6]; Ozkul et al. [7]. Through these investigations, there were separated parameters, which have influence on the stress increment in unbounded tendons. These are; span-to-depth ratio, concrete compressive strength (normal strength and high strength concrete), yield strength, tendon profile, tensile strength and amount of non-prestressed and prestressed reinforcement, type of loading (single point load, third-point loading and uniformly distributed load), loading pattern in continuous members (uniform loading, alternate spans, adjacent spans, external span or internal span) and stress in the tendon after time dependent losses. These parameters have caused formulating of tendon stress was more complicated. Since the early 1950s, researchers have suggested many experimental and analytical equations for prediction of stress in tendon at an ultimate state, which have been evaluated and reviewed by Harajli and Kanj; Naaman and Alkhairi [8]; Ament et al. [9]; Harajli [10]; Manisekar and Senthil [11]; Dall’Asta et al. [12]; He and Liu [13], that these equations don’t account all of important parameters and worked with nearly low strength concrete.
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Analysis of Geopolymer Concrete Columns at Normal and High Strength

Analysis of Geopolymer Concrete Columns at Normal and High Strength

geopolymer concrete which are favorable for its use as a construction material. The effect of the exposure to direct fire on the behavior of high strength concrete columns,[4]. Each of them concluded that the exposure to either elevated temperature or fire causes severe reduction in the ultimate capacity of the tested columns. It reported that exposure to 550°C elevated temperatures adversely affected the structural behavior of the tested columns under uni-axial bending moment in terms of residual capacity, serviceability performance, stiffness and toughness, [5]. Sumajouw et aland Sujatha et al ,[6&7] conducted experiments on low calcium fly ash GPC slender circular columns and found that it possesses higher load carrying capacity and better ductility than conventional concrete columns (RCC). It proposed the stress-strain model for GPC and it was validated by using it for the analysis of the GPC column. Studies on the effect of temperatures on the strength and behavior of GPC columns under axial loading have not come across. Since GPC requires temperature curing it is more suitable for prefabricated construction. The prefabricated industry has evolved to a stage that even multi-storeyed buildings can be constructed using an assemblage of individual structural elements(beams, columns, slabs. wall panels). Once the behavior of GPC structural elements is understood, it can be used for various construction purposes,[8]. The carried out literature review indicated that the results of the previous researches gave irreconcilable behavior for the geopolymer concrete. Moreover, more advanced studies are still needed for understanding the structural behavior of the reinforced concrete elements made of geopolymer materials. These advanced studies can help in recognizing the effect of the type of the geopolymer concrete on their behavior and the optimum percentages of temperature which can be used. However, very little information are available about the behavior of reinforced concrete columns made of geopolymer concrete,[9&10]. Accordingly, the current research aims to investigate the structural behavior of axially loaded reinforced concrete square short columns made of geopolymer concrete. The effects of four main variables on the structural behavior of the columns are experimentally investigated. These variables are the temperature of 300 at 1hr., 300 at 2hr., 500 at 1hr. and 500 at 2hr.
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Bond Behavior of High Performance Reinforcing Bars for Concrete Structures

Bond Behavior of High Performance Reinforcing Bars for Concrete Structures

The effect of concrete compressive strength on the bond characteristics have been studied by many researchers. This effect is related to the square root of the compressive strength of the concrete in most of the equations describing the bond strength. It was found that the accuracy of such normalization is adequate up to compressive strength of 8000 psi then decreases as the compressive strength increases (Azizinamini, Chisala and Ghosh, 1995; Zuo and Darwin, 1998). The bearing action between the rib of the reinforcing steel and the high strength concrete is different than with normal strength concrete; as the bearing capacity increases more rapidly than the tensile strength preventing the crushing of the concrete in front of the ribs and thus reducing slip, this reduced slip results in fewer ribs transferring the load which increases the local tensile stresses and initiates the splitting failure in the concrete before achieving a uniform stress distribution along the splice or development length (Azizinamini, Chisala and Ghosh, 1995).
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BEHAVIOUR OF SUGACANE BAGASSE ASH WHEN EXPOSED TO NACL SOLUTION

BEHAVIOUR OF SUGACANE BAGASSE ASH WHEN EXPOSED TO NACL SOLUTION

Construction officials in coastal areas have long been facing the challenge of building and maintaining durable concrete structures in a saltwater environment. Gradual penetration of sea salts and the subsequent formation of expansive and leachable compounds lead to disintegration of structural concrete. The average NaCl concentration of sea water is about 3.5% although it varies from sea to sea depending upon geological location. In this study bagasse ash is used because it is one of the main by product can be used as mineral admixture due to its high content in silica (SiO2).In this study, Bagasse ash has been chemically and physically characterized, and partially replaced in the ratio of 0%, 5%,10%,15% and 20% by weight of cement in concrete. Fresh concrete tests like compaction factor test and slump cone test were undertaken was well as hardened concrete test compressive strength at the age of 7,28 and 60 days was obtained. The result shows that the strength of concrete .Concrete specimens were cured in normal water and NaCl solution and comparison is made between them.
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Mechanical Behavior of Recycled Fine Aggregate Concrete with High Slump Property in Normal- and High-Strength

Mechanical Behavior of Recycled Fine Aggregate Concrete with High Slump Property in Normal- and High-Strength

The mixing proportions for NS and HS concrete were designed according to the change in the replacement ratio of RFA. The design strengths were 30  MPa and 60  MPa for NS and HS concrete, respectively. Five replacement ratios (i.e., 0%, 15%, 30%, 50%, and 100% by weight) were selected, resulting in a total of ten mixing proportions (see Table  3). Notably, concrete with zero replacement ratio of RFA, referred to as virgin concrete, provides the reference mechanical behaviors. The speci- men IDs indicate the design strength and RFA replace- ment ratio. Aggregates were prepared under the SSD condition ASTM 128C (2015), and thus the effective w/c ratio was used in this study. Up to 10% and 20% of mineral admixtures of FA and GGBS, respectively, were added. These pozzolanic ingredients are known to reduce the hydration heats, which can decrease shrink- age cracks. Furthermore, they significantly improved the mechanical and durability properties of recycled aggre- gate concrete (Kumar et  al. 2017). A high slump value was maintained for all the mixing proportions by cali- brating the amount of polycarboxylate-based superplas- ticizer (SP). For NS concrete, 3.16–3.75 kg/m 3 of SP was
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Strength And Cost Comparison Of Normal And High Volume Fly Ash Concrete

Strength And Cost Comparison Of Normal And High Volume Fly Ash Concrete

Fortunately, a waste product Fly Ash can be substituted for large portions of Portland cement, significantly improving concrete’s environmental characteristics. Fly Ash, consisting mostly of silica, alumina, and iron, forms a compound similar to Portland cement when mixed with lime and water. Fly ash is a non- combusted by-product of coal-fired power plants and generally ends up in a landfill. However, when high volumes are used in concrete (displacing more than 25% of the cement), it creates a stronger, more durable product and reduces concrete’s environmental impact considerably. Due to its strength and lower water content, cracking is reduced.
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An Experimental Investigation on Strength Characteristic of High Density Concrete incorporating hematite

An Experimental Investigation on Strength Characteristic of High Density Concrete incorporating hematite

Concrete has an extensive role to play both in construction and improvement of our civil engineering and infrastructure. It’s great strength, durability and versatility are properties that are utilized in the construction of roads, bridges, airport, railways, tunnels, ports and harbors and many other major infrastructure projects. To call the concrete, as high density concrete, it must have unit weight ranging from 3360 kg/m 3 to 3840 kg/m 3 . They can, however be produced with the densities up to about 5280 kg/m 3 High density concrete offers reliable, cost-efficient radiation shielding and can be used alongside other shielding materials to maximize protection in the available space. High density aggregates are the key ingredient in High density concrete. The more common aggregates used to achieve the required densities are Hematite, Ilmenite, Magnetite and Steel aggregate. The concrete was studied using Hematite (iron ore) having a density varies from 3400-3600 Kg/m 3 . Several properties of concretes with design mix of M30 grade were also studied that include the compression, The high density concrete was also compared with normal weight concrete of the same strength grade with respect to the above parameters. Based on the experimental investigations carried on the conventional concrete, high density Concrete has more Compressive strength, Split tensile strength, flexural strength values are found out.
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