scholarly journals Effect of Coconut Fiber Length and Content on Properties of High Strength Concrete

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1075 ◽  
Author(s):  
Waqas Ahmad ◽  
Syed Hassan Farooq ◽  
Muhammad Usman ◽  
Mehran Khan ◽  
Ayaz Ahmad ◽  
...  
Keyword(s):  
High Strength Concrete ◽  
Fiber Length ◽  
Natural Fibers ◽  
Construction Materials ◽  
High Strength ◽  
Coconut Fiber ◽  
Strength Concrete ◽  
Super Plasticizer ◽  
Scanning Electron ◽  
Coconut Fibers

Recently, the addition of natural fibers to high strength concrete (HSC) has been of great interest in the field of construction materials. Compared to artificial fibers, natural fibers are cheap and locally available. Among all natural fibers, coconut fibers have the greatest known toughness. In this work, the mechanical properties of coconut fiber reinforced high strength concrete (CFR-HSC) are explored. Silica fume (10% by mass) and super plasticizer (1% by mass) are also added to the CFR-HSC. The influence of 25 mm-, 50 mm-, and 75 mm-long coconut fibers and 0.5%, 1%, 1.5%, and 2% contents by mass is investigated. The microstructure of CFR-HSC is studied using scanning electron microscopy (SEM). The experimental results revealed that CFR-HSC has improved compressive, splitting-tensile, and flexural strengths, and energy absorption and toughness indices compared to HSC. The overall best results are obtained for the CFR-HSC having 50 mm long coconut fibers with 1.5% content by cement mass.

scholarly journals Dynamic displacement analysis of reinforced concrete deep beams made of high strength concrete. Part II: Dynamic displacement analysis of reinforced concrete deep beams made of high strength C200 grade concrete

2018 ◽  
Vol 67 (2) ◽  
pp. 25-48
Author(s):  
Waldemar Cichorski
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Load ◽  
High Strength Concrete ◽  
Construction Materials ◽  
High Strength ◽  
Deep Beam ◽  
Deep Beams ◽  
Dynamic Displacement ◽  
Displacement Analysis ◽  
Strength Concrete

The dynamic load displacements were analysed of rectangular concrete deep beams made of very high strength concrete, grade C200, including an evaluation of the physical non-linearity of the construction materials: concrete and reinforcing steel. The analysis was conducted using the method presented in [1]. The numerical calculation results are presented with particular reference to the displacement state of rectangular concrete deep beams. A comparative analysis was conducted on the effect of the high-strength concrete and the steel of increased strength on a class C200 concrete deep beam versus the results produced in [10] for a class C100 concrete deep beam. Keywords: mechanics of structures, reinforced concrete structures, deep beams, dynamic load, physical non-linearity

scholarly journals Lightweight high-strength concrete with the use of waste cenosphere as fine aggregate

2019 ◽  
Vol 24 (4) ◽  
Author(s):  
Felipe Basquiroto de Souza ◽  
Oscar Rubem Klegues Montedo ◽  
Rosielen Leopoldo Grassi ◽  
Elaine Gugliemi Pavei Antunes
Keyword(s):  
High Strength Concrete ◽  
Power Plants ◽  
Lightweight Concrete ◽  
Construction Materials ◽  
Hollow Structure ◽  
High Strength ◽  
Cementitious Materials ◽  
Partial Substitution ◽  
Fine Aggregate ◽  
Strength Concrete

ABSTRACT Cenosphere is a coal combustion by-product that presents interesting properties to be used in the production of cementitious materials, such as hollow structure, low density, low thermal conductivity and notably thermal stability. In addition, it displays pozzolanic reactivity under thermal curing. However, the cenosphere potential for the development of unique construction materials has not been fully investigated, remaining obscure for both power plants and the construction field. This study investigated the employment of waste cenosphere in partial substitution to sand for the obtainment of high-strength lightweight concrete materials. Cenosphere from a Brazilian power plant was chemically and physically characterized and the feasibility of its use in concretes was investigated. It was discovered that the power plant’s fly ash is composed of approximately 0.2% of cenosphere. In addition, the cenosphere displayed size ranging from 30 to 300 µm and were suitable for use as fine aggregate in concrete. Concrete with 33, 67, and 100% fine aggregate replacement by the waste cenosphere was produced. Cenosphere-based high strength concrete presented strength higher than 70 MPa and density as low as 1500 kg • m-3. Compared to mixes of reference, cenosphere application as fine aggregate improved the specific strength of high-strength concrete while maintaining equivalent mechanical properties.

scholarly journals Development of Ultra High Strength Concrete Using Silica Fume and its Mechanical & Durability Properties - Experimental Investigation

2021 ◽  
Author(s):  
Sathyakumar N ◽  
Arun M ◽  
Arunachalam N
Keyword(s):  
Experimental Investigation ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Coarse Aggregate ◽  
High Strength ◽  
Chloride Penetration ◽  
Fine Aggregate ◽  
Strength Concrete ◽  
Super Plasticizer

Abstract This experimental investigation is aimed to develop an ultra-high strength concrete with minimum of 100 MPa as compressive strength.In order to obtain this, twenty different concrete mixes have been tried, using cement, river sand, coarse aggregate, water, silica fume and super plasticizer. During the preparation of trial mixes of concrete, the water / binder ratio of 0.2, silica fume of 10% to the weight of cement, super plasticizer of 10 litres per cubic metre of concrete and coarse aggregate of 1000 kg/m3 were kept as constant. The amount of cement content (as 600-, 650-, 700-, 750- and 800 kg/m3) and the fine aggregate content (as 500-, 600-, 700- and 800 kg/m3) was varied. Totally 300 specimens were cast and tested in this investigation.The100 x 100 x 100 mm size of cubes, 150 x 300 mm size of cylinders, 100 x 100 x 500 mm size of prisms, 100 x 200 mm size of cylinders, 60 x 100 mm size of cylinders were used to test compressive, split tensile, flexural strength, chloride penetration and water penetration tests respectively at the age of 7-, 14- and 28 days. Based on the test results, a suitable mix proportion to produce an ultra-high strength concrete has been identified. Subsequently, from this investigation, the maximum cube compressive strength of 130 MPa, split tensile strength of 6.94 MPa, flexural strength of 21.39 MPa, chloride penetration 36 Coulombs which is lesser than 100 and sorptivity coefficient valueof 0.582 has been achieved.

scholarly journals High Strength Concrete Small Hollow Blocks Made with Rock Chips as Aggregates

2012 ◽  
Vol 5 ◽  
pp. 333-338
Author(s):  
Yong Quan Zhang ◽  
Jie Yuan ◽  
Yong Ge
Keyword(s):  
Compressive Strength ◽  
Solid Waste ◽  
High Strength Concrete ◽  
Construction Materials ◽  
High Strength ◽  
Masonry Structure ◽  
Strength Concrete ◽  
Industrial Solid Waste ◽  
Structural Applications ◽  
Curing Methods

It is more and more general of using industrial solid waste as the aggregates in construction materials for non-structural applications. But because of the developments and applications of reinforced blocks masonry structure in the modern masonry structure, especially in the mid-high and high storey buildings, there will be a growing interest of using industrial solid waste to produce high strength concrete small hollow blocks for structural applications. This experiment by mixing the different proportions of rock chips within the range of 30-70% as the replacement for sand prepared high strength concrete small hollow blocks which the compressive grade is MU 15.0, the influence of aggregates grading on the compressive strength of high strength concrete small hollow blocks was investigated at the same water/cement (w/c) ratio (0.45). In addition, the influence of the different curing methods on the compressive strength and shrinkage of high strength concrete small hollow blocks were also investigated, test results showed that high strength concrete small hollow blocks under the curing method which is the one-time pouring the ample amount of water, covered and sealed with plastic sheeting, the compressive strength had a better development, and the total shrinkage was larger than others.

scholarly journals Analisa Pengaruh Penggunaan Serat Serabut Kelapa dalam Presentase Tertentu pada Beton Mutu Tinggi

2015 ◽  
Vol 6 (2) ◽  
pp. 208 ◽  
Author(s):  
Eduardi Prahara ◽  
Gouw Tjie Liong ◽  
Rachmansyah Rachmansyah
Keyword(s):  
Tensile Strength ◽  
Concrete Beams ◽  
High Strength ◽  
Strong Relationship ◽  
Test Results ◽  
Coconut Fiber ◽  
Additional Material ◽  
Strength Concrete ◽  
Cylinder Compression ◽  
Coconut Fibers

The use of additional material as ingredients in the manufacture of concrete mixes is increasingly growing. The material used is also increasingly varied, depending on the expected results. This research aims to know the influence of the addition of coconut fibres material with percentage of 1,5 %, 2 %, 2,5 %, and 3 % as an alternative to the strength of high-quality concrete. Research methods done by producing cylindrical and beam concrete samples for testing against the force then conducted concrete. Furthermore, the analysis has been done and the results of testing and comparing the respective strength of the composition of concrete produced. Based on the test results of data concrete cylinder compression strength and tensile strength concrete beams, it was concluded that the increasing of compressive strength up to 9% can be reached by use of additional material coconut fibers 1,5%and increasing of tensile strength up to 19,7% can be reached by use of additional coconut fiber 2%. Therefore, the additional coconut fibers on concrete mixture has strong relationship to increase tensile strength of high strength concrete.

scholarly journals Determination and Review of Physical and Mechanical Properties of Raw and Treated Coconut Fibers for Their Recycling in Construction Materials

Fibers ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 37
Author(s):  
Huyen Bui ◽  
Nassim Sebaibi ◽  
Mohamed Boutouil ◽  
Daniel Levacher
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Natural Fibers ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Coconut Fiber ◽  
Vegetable Fibers ◽  
Durability Properties ◽  
The Past ◽  
Coconut Fibers

In order to reduce the dependency on conventional materials and negative environmental impacts, one of the main responsibilities of the construction field is to find new eco-friendly resources to replace the traditional materials partially. Natural fibers were known as potential candidates for the reinforcement of structures in civil engineering by virtue of their advantages. Among the different kinds of vegetable fibers, coconut fiber has been exploited in a limited way over the past few years. This paper aims at evaluating the different properties of local coconut fibers (Vietnam). Several laboratory tests provide geometrical, physical, mechanical properties and durability properties that are compared with literature results obtained from similar natural fibers. The local coconut fibers tested demonstrated properties suitable for reinforced mortars. With adequate control of their preparation, they could be reused in the manufacture of mortars in the construction.

The Properties of High-Strength Concrete Containing Super-Fine Fly Ash and Limestone Powder

2013 ◽  
Vol 477-478 ◽  
pp. 926-930
Author(s):  
Jin Hu ◽  
Meng Yuan Li
Keyword(s):  
Fly Ash ◽  
High Strength Concrete ◽  
High Strength ◽  
Limestone Powder ◽  
Cement Concrete ◽  
Carbonation Depth ◽  
Adiabatic Temperature Rise ◽  
Strength Concrete ◽  
Super Plasticizer ◽  
Lower Permeability

In this study, a high-strength concrete containing 25% super-fine fly ash and 10% limestone powder was prepared, and its properties were investigated by comparing with those of pure cement concrete. The results show that the concrete containing super-fine fly ash and limestone powder can get a larger initial slump and a smaller slump loss than the pure cement concrete with the same super plasticizer content. In the case of almost the same 28 days' compressive strength, the concrete containing super-fine fly ash and limestone powder exhibits a lower adiabatic temperature rise, a lower early strength, a higher late strength, a lower permeability, and a larger carbonation depth than the pure cement concrete.

scholarly journals Effect of Alternate Wetting and Drying on some Properties of High Strength Concrete in Tropical Coastal Environments

2020 ◽  
Vol 4 (1) ◽  
pp. 172-181
Author(s):  
O. R. Ogirigbo ◽  
O. M. Durojaye
Keyword(s):  
Compressive Strength ◽  
Transport Properties ◽  
High Strength Concrete ◽  
Construction Materials ◽  
High Strength ◽  
Ambient Air ◽  
Chloride Ingress ◽  
Wetting And Drying ◽  
Strength Concrete ◽  
Alternate Wetting And Drying

Concrete is one of the most used construction materials in the world, due to its good durability and fire resistance properties, versatility in forming various shapes, abundance of raw materials and low manufacturing and maintenance costs. High strength concrete, which is a type of concrete, finds its application in construction of high rise buildings, bridges, highways, etc. Its physical properties are greatly affected by the method of curing and the environment in which it is placed. This study investigated the effect on the compressive strength and some transport properties of high strength concrete subjected to alternate wetting and drying exposure, which may be due to intermittent rains, or rise and fall in tides of the sea, an exposure type that is commonly experienced in coastal areas. High strength concrete samples were prepared and subjected to two different curing regimes, one in which the concrete samples were cured continuously under water, and the other in which the concrete samples were subjected to 12-hr curing under water followed by 12-hr curing under ambient air. Various tests such as ultrasonic pulse velocity (UPV), compressive strength, water and chloride ingress tests were conducted on the cured concrete samples. The results obtained from the tests conducted, generally showed that the strength and transport properties of the high strength concrete was greatly affected by the alternate wetting and drying curing method. The effect was seen to be more adverse at the later ages than at the early ages.

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