1. Ratio of Cement to the Mixing Water. For concrete that has to be compacted by a vibrator, a lower water cement ratio may be used. The maximum strength is derived at w/c = 0.4. When the water cement ratio is less than 0.4, there is improper consistency and workability of the cement and honeycombed structure. 2.
Hence our test result is valid. Factors affecting test results of the specimen. Now as you know the test procedure, you should be aware of the factors that can potentially affect the test results. Some of the important factors are listed below. 1) State of moisture – The concrete specimen is subjected to curing until the day of testing. On ...
Types of Slump in Concrete. The slump test is the most critical and standard test on fresh concrete. Understanding this test and recognizing when it was performed incorrectly is essential. 1. True Slump. When …
The following major factors that affect the relationship between the in-place strength and the strength of molded cylinders were assessed in this project: concrete age, concrete …
The interaction of reinforcement bars with concrete determines the structural behavior and bond performance (bond strength) in reinforced cement concrete. Bond strength and its importance in structural applications based on available standards attracted researchers around the globe to evaluate the bond strength in reinforced cement …
There are 5 factors which influence strength of concrete when tested for compressive strength. These factors are mentioned below. Shape & Size of Test Specimens. Height to Diameter Ratio. Rate of Application of Load. Moisture Content in the Test Specimen. Material Used for Capping. 1. Shape & Size of Test Specimens.
Aggregates make up between 60% and 80% of the volume of concrete, being surrounded by the cement paste. Aggregates are considered to be the most important factor affecting concrete strength. ... aggregates can be considered as one of the major factors, affecting concrete permeability. However, during the compressive strength test, …
HSC experiences a rapid loss of tensile strength at higher temperatures due to development of pore pressure in dense microstructured HSC [].The addition of steel fibers to concrete enhances its tensile strength and the increase can be up to 50% higher at room temperature [67, 68].Further, the tensile strength of steel fiber-reinforced concrete …
Part 13 - Strength. Strength may not be the most important characteristic of concrete; durability, volume stability, and impermeability may be equally significant. However, strength has become universally accepted as the most important indication of concrete quality. Factors that effect concrete strength may be divided into four categories: (1 ...
The most reliable and the most commonly used standardized [36] method for assessing concrete in structures is the determination of compressive strength in a destructive test. Cylindrical specimens with a diameter of 50 to 250 mm, cut from a structure using a core drilling machine, are usually used in the test.
Quality control of concrete refers to the factor that governs this difference for concrete of a given strength level. Quality control of concrete, in other words, is the control of variation in the properties of the mix ingredients as well as the accuracy of all operations that affect the strength or consistency of concrete.
To estimate the behavior of externally prestressed concrete beams FEM, the T-1D beam prototype in Ref. [], the SSS1 beam specimen in Ref. [], and the S1 beam fabricated by the authors in the structural laboratory of the Noshirvani University of Technology in Babol were modeled.The obtained FEM results were then validated with …
The Compressive strength of specimen can be calculated by dividing maximum load carried by the specimen by cross-sectional area of the specimen cubes. The surface area of specimen: = 150 x 150 = 22500mm² = 225cm². Assume, The Max compression load is 450KN. 1KN = 1000N ; 450Kn = 450×100 = 450000N.
3.1. Current Egyptian Code (2008)/standard and British Code (2003) According to these codes, the estimated in-situ concrete cube strength (f cu) may be calculated from the measured compressive strength of core (f core) according to the following expression: (1) f cu = (F l / d) · (F Reinf.) f core where the factors (F l / d) and …
1. Introduction. Concrete's freeze-thaw damage [] leads to premature cracking and other deterioration of concrete [], which have seriously impaired the service life of concrete, and is one of the primary problems that affect the durability of concrete [3,4,5,6,7,8].Air-entraining technology [] is one of the most widely adopted technical …
The principal factors affecting the measured strength of a concrete specimen: - Selecting the size and shape of the specimen. - Taking the sample (ASTM C172). - Making the …
The size and shape of the strength test specimen affect the indicated strength. If we assume that 100 percent represents the compressive strength indicated by a standard 6 …
the influence of various cements on the strength and durability of concrete. Traditional factors such as cement content and water-cement ratio were not intended to be variables. These two factors have a profound influence on the strength and durability of concretes made from a single cement. Within
Water/Cement/Aggregate Ratio. The ratio in which you add the different components of the concrete together is an incredibly key factor in creating strong or weak concrete. By adding more or less of just one of the raw materials will create a completely different form of concrete, and while different forms of concrete are better utilised in ...
The literature has been reviewed for three factors affecting concrete compression testing. From our conclusions, some further studies can be recommended: 1) Higher strength concretes are not yet fully understood. More research on the relation between the concrete grade and the various factors should be conducted. 2)
The water-cement ratio is the first parameter we used when starting to work out the concrete mix design. This the dominant amongst all other factors affecting concrete mix design. The lower the water-cement ratio, the higher the strength of the concrete as the cement content increase compared to water content.
Q. What test conditions affect the results of compressive strength tests of concrete? A. The principal factors affecting the measured strength of a concrete specimen: - Selecting the size and shape of the specimen. - Taking the sample (ASTM C172). - Making the specimen (ASTM C31 or C192). - Handling and transporting the specimen (ASTM C31 ...
This study investigated the effects of cold joints on the strength and some durability properties of concrete. In the first part of the study, fresh concrete was poured into molds filling them half in order to create a horizontal cold joint and after 0, 60, 120 and 180 min additional concrete was poured to top off the molds. The specimens were …
Water/cement ratio is one of the most important factor which influence the concrete workability. Generally, a water cement ratio of 0.45 to 0.6 is used for good workable concrete without the use of any admixture. Higher the water/cement ratio, higher will be the water content per volume of concrete and concrete will be more workable.
Our second tip is not to use excessive water when pouring concrete. Instead, mist concrete 2-3 times a day for three days after you pour it. Wetting the concrete's exterior during the three-day curing …
This study aims to investigate the influence of all the mixture components of high-performance concrete (HPC) on its early compressive strength, ranging from 1 to 14 days. To this purpose, a Gaussian Process Regression (GPR) algorithm was first constructed using a database gathered from the available literature. The database …
However, later, it has been recognized that there are other factors influencing the compressive strength of concrete such as cement properties, gradation of …
The results of flexural tensile strength experimental study are given in Table 2, Table 3, Table 4 for different concrete mixes at 7-days, 28-days and 56-days and specimens under different confinement. Table 5 depicts the level of concrete strength effect on the flexural tensile strength without confining conditions of concrete. It is clear …
Workability of concrete can be divided into following three types: Unworkable Concrete. Medium Workable. Highly Workable Concrete. 1. Unworkable Concrete - Harsh Concrete. An unworkable concrete can …
