scholarly journals Properties of Rubberized Engineered Cementitious Composites Containing Nano-Silica

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3765
Author(s):  
Rubendran Loganathan ◽  
Bashar S. Mohammed
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Drying Shrinkage ◽  
Poisson's Ratio ◽  
Cementitious Composites ◽  
Nano Silica ◽  
Engineered Cementitious Composites ◽  
Direct Tensile ◽  
Direct Tensile Strength

To avoid explosive spalling during elevated temperature, crumb rubber (CR) is being added to the manufacturing of engineered cementitious composites (ECC). However, the addition of CR particles adversely affects the mechanical properties of ECC. Therefore, to overcome this issue, nano-silica (NS) is added into rubberized ECC mixture as cementitious material additives. Response surface methodology (RSM) has been utilized to optimize the mixtures of the rubberized ECC with variables: CR (0, 2.5, and 5 vol.%), polyvinyl alcohol (PVA) fiber (0, 1, and 2 vol.%), NS (0, 1, and 2 vol.%), and fly ash (0, 25, and 50 vol.%). The experimentally measured responses are flexural strength, direct tensile strength, elastic modulus, Poisson’s ratio, creep, and drying shrinkage. Mathematical models to predict the targeted responses have been developed using RSM. As a result, a high correlation between the factors and responses has been exhibited by the developed models and the accuracy of fit, where less than 9.38% of the variation was found between the predicted and validated results. The experimental results revealed that the rubberized ECC with the incorporation of nano-silica exhibited a higher compressive strength, direct tensile strength, flexural strength, elastic modulus, Poisson’s ratio, and lower drying shrinkage.

Influence of Concrete Strength Grade and Age on Three Tensile Strengths

2012 ◽  
Vol 450-451 ◽  
pp. 179-186
Author(s):  
Xi Xi He ◽  
Ping Fang
Keyword(s):  
Tensile Strength ◽  
Flexural Strength ◽  
Concrete Strength ◽  
Test Methods ◽  
Uniaxial Tensile ◽  
Strength Parameters ◽  
Uniaxial Tensile Strength ◽  
Fly Ash Concrete ◽  
Direct Tensile ◽  
Direct Tensile Strength

Uniaxial tensile strength is one of the important strength parameters of concrete. In this study, two test methods were applied to determine direct tensile strength, splitting tensile strength and flexural strength of fly ash concrete specimens with the same cross section and different strength grades. Relationship among the uniaxial tensile, splitting tensile and flexural strength of concrete were researched. Furthermore, the influence of concrete strength and age to the three tensile strengths were specifically analyzed in the paper.

scholarly journals A Study of Engineered Cementitious Composites by Investigating its Compressive and Flexural Strength

2021 ◽  
Author(s):  
SONA ROSE BINS ◽  
CENYA S KUMAR ◽  
Shivani Ittuveetil ◽  
SONA TOGI ◽  
MAREENA GEORGE
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Crack Width ◽  
Critical Issue ◽  
Cementitious Composites ◽  
Engineered Cementitious Composites ◽  
Unique Type ◽  
Negative Effect ◽  
Ductile Behavior

Abstract Concrete has become an essential material as a part of construction field. Its behavior is weak in tension and strong in compression. The demand for tensile strength is high for concrete because higher loading requires more than 10% of compressive strength which make a critical issue for engineers. Another major issue faced by normal concrete is lack in ductility and strain capacity. Engineered Cementitious Composites (ECC), also known as Bendable Concrete, has been designed to overcome the brittleness of concrete. It has tensile ductility of 3–5% and its self-controlled tight crack width is less than 100µm.It is a unique type of cement mixture with composition of low volume fibers (~ 2%) so as to impart ductility, ability to repair and high tensile strength besides. It also has low maintenance and is environment friendly in nature.The ECC composition does not contain coarse aggregate because they develop larger crack width which tend to have a negative effect on ductile behavior of ECC. This paper demonstrated a detailed review on properties of ECC and experimentally identified the best ECC mix by analysing the compressive the flexural strength at different ratios: 0.5%, 1%, 1.5%, 2% and 2.5% of PVA fibre. Fifteen cubes (150mm x 150mm x 150mm) were casted for compressive strength test and fifteen beams (500mm x 100mm x 100mm) were casted for flexural strength and tested at the age of 28 days. Workability test have been conducted to access the fresh properties and consistency of the concrete.

scholarly journals IX. On the existence of an element of strength in beams subjected to transverse strain, arising from the lateral action of the fibres or particles on each other, and named by the author the 'resistance of flexture.’

1855 ◽  
Vol 145 ◽  
pp. 225-242
Keyword(s):  
Tensile Strength ◽  
Cast Iron ◽  
Neutral Axis ◽  
Direct Compression ◽  
Transverse Strain ◽  
Direct Tension ◽  
Direct Tensile ◽  
Direct Tensile Strength

It has been long known, that under the existing theory of beams, which recognizes only two elements of strength, namely, the resistances to direct compression and extension, the strength of a bar of cast iron subjected to transverse strain cannot be reconciled with the results obtained from experiments on direct tension, if the neutral axis is in the centre of the bar. The experiments made both on the transverse and on the direct tensile strength of this material have been so numerous and so carefully conducted, as to admit of no doubt of their accuracy; and it results from them, either that the neutral axis must be at, or above, the top of the beam, or there must be some other cause for the strength exhibited by the beam when subjected to transverse strain.

scholarly journals Determination of Direct Tensile Strength Values of Rock Materials by a New Test Method of Drilled Disc Tension

2019 ◽  
Author(s):  
Eren Komurlu ◽  
Serhat Demir
Keyword(s):  
Tensile Strength ◽  
Experimental Studies ◽  
Test Method ◽  
Uniaxial Tensile ◽  
Direct Tension ◽  
Rock Materials ◽  
Uniaxial Tensile Stress ◽  
Direct Tensile ◽  
Drill Holes ◽  
Direct Tensile Strength

Use of drilled disc specimens was investigated with both numerical and experimental studies to determine direct tensile strengths of rock materials. A new loading apparatus with rods to insert into the drill holes of discs has been designed and manufactured to supply tension by using the compression test presses. In addition to the use of popular compressive presses for direct tension, elimination of the gluing in the standard direct tensile strength test method is a significant advantage to make possible both hard and soft rocks to be tested. The Brazilian test discs with the diameter of NX size and length to diameter ratio of 0.5 were used in tests. Different loading apparatus designs were analyzed and ideal angle of contact between rock and the loading rods was assessed to be 50° within various choices investigated in this study. The drilled discs were determined to fail due to the crack initiation under the condition of uniaxial tensile stress distribution at sidewalls of the hole. In addition to the drilled disc tension test, standard direct tensile strength tests were also carried out to take as reference and compare the results obtained from different methods. According to the results of both numerical and experimental studies, an equation was suggested to determine uniaxial tensile strengths of drilled disc specimens with 20 mm hole diameter and the contact angle of 50°.

scholarly journals Tensile Behavior Characteristics of High-Performance Slurry-Infiltrated Fiber-Reinforced Cementitious Composite with Respect to Fiber Volume Fraction

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3335 ◽  
Author(s):  
Seungwon Kim ◽  
Dong Joo Kim ◽  
Sung-Wook Kim ◽  
Cheolwoo Park
Keyword(s):  
Tensile Strength ◽  
Energy Absorption ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Absorption Capacity ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Energy Absorption Capacity ◽  
Direct Tensile ◽  
Direct Tensile Strength

Concrete has high compressive strength, but low tensile strength, bending strength, toughness, low resistance to cracking, and brittle fracture characteristics. To overcome these problems, fiber-reinforced concrete, in which the strength of concrete is improved by inserting fibers, is being used. Recently, high-performance fiber-reinforced cementitious composites (HPFRCCs) have been extensively researched. The disadvantages of conventional concrete such as low tensile stress, strain capacity, and energy absorption capacity, have been overcome using HPFRCCs, but they have a weakness in that the fiber reinforcement has only 2% fiber volume fraction. In this study, slurry infiltrated fiber reinforced cementitious composites (SIFRCCs), which can maximize the fiber volume fraction (up to 8%), was developed, and an experimental study on the tensile behavior of SIFRCCs with varying fiber volume fractions (4%, 5%, and 6%) was carried out through direct tensile tests. The results showed that the specimen with high fiber volume fraction exhibited high direct tensile strength and improved brittleness. As per the results, the direct tensile strength is approximately 15.5 MPa, and the energy absorption capacity was excellent. Furthermore, the bridging effect of steel fibers induced strain hardening behavior and multiple cracks, which increased the direct tensile strength and energy absorption capacity.

Comparison of Tensile Strengths with Different Test Methods in Ultra High Strength Steel-Fiber Reinforced Concrete (UHS-SFRC)

2009 ◽  
Vol 417-418 ◽  
pp. 649-652 ◽  
Author(s):  
Su Tae Kang ◽  
Jung Jun Park ◽  
Gum Sung Ryu ◽  
Gyung Taek Koh ◽  
Sung Wook Kim
Keyword(s):  
Tensile Strength ◽  
Tensile Test ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Steel Fiber Reinforced Concrete ◽  
Flexural Tensile Strength ◽  
Ultra High Strength Steel ◽  
Direct Tensile ◽  
Direct Tensile Test ◽  
Direct Tensile Strength

Ultra High Strength Steel-Fiber Reinforced Concrete (UHS-SFRC) is characterized by very high compressive and tensile strength that is about 8 times of ordinary concrete, and high ductility owing to the addition of steel fibers. This paper investigates the relationship existing among the direct tensile strength, flexural tensile strength and splitting tensile strength of UHS-SFRC. Differently from ordinary concrete, it is found that the first cracking strengths in UHS-SFRC obtained through direct tensile test and splitting tensile test are similar, while the strength obtained from flexural tensile test is significantly larger than those from other tests. Based on the experimental results, relationships between the direct tensile strength and flexural tensile strength, between the first cracking strengths in direct tensile test and in flexural tensile test, and between the first cracking strength in direct tensile test and the flexural tensile strength are proposed.

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