Factors affecting concrete mix design strength the mixing of concrete constituent materials i. This is in contrast to the performance of the concrete mixes which shows consistent decrease of compressive strength in watercement ratio. Statistical analysis was performed on test data consisting of chemical and physical properties of cements. In high strength concrete, the compressive strength of concrete with aggregates having basalt are found to have higher strength than that of the aggregates with limestone, but the results are exactly opposite in normal strength concrete. Therefore, to ensure the functional performance and safety of structure it is necessary to determine the true strength of concrete. The coarse aggregate used in the experimental investigation is a mixture of 20mm and 10mm size aggregates. Factors affecting the tensile properties of concrete. Effect of aggregate flakiness on the compressive strength and. Effects of key factors on compressive and tensile strengths. The mean compressive strength for the 15mm was higher 20 mm than the 10mm mm coarse aggregates. Figure 3 shows that the compressive strength increases normally when the ratio diminishes. Quality of aggregates, its size, shape, texture, strength.
An experimental campaign has an experimental campaign has been conducted on a broad group of cubic specim ens made of foamed concrete. Flaky aggregates, workability, compressive strength, concrete cube, concrete. Based on my literature research, i believe that the more water added relative to the amount of cement will decrease the compressive strength of the concrete. It consists essentially of cement, fine aggregate sand and coarse aggregate natural gravels or chippings. Factors that affect the strength of concrete california science. Pdf key factors affecting the compressive strength of foamed. Some factors affecting the compressive strength of concrete.
Is durability directly related to strength of concrete. The superplasticizer was added to the concrete at 0%, 2%, 2. Jul 05, 2018 in high strength concrete, the compressive strength of concrete with aggregates having basalt are found to have higher strength than that of the aggregates with limestone, but the results are exactly opposite in normal strength concrete. Higher strengths up to and exceeding 10,000 psi 70 mpa are specified for certain applications. Hardening belongs to the method of growth of strength. Effects of watercement ratios on the compressive strength. Effect of hand mixing on the compressive strength of concrete. Since the water cement ratio has increased, the compressive strength will decrease. Compressive strength of fly ash concrete silicon dioxide sio line chart wc 0.
Effect of aggregate type on compressive strength of concrete. Compressive strength model for concrete article pdf available in magazine of concrete research 659. Some factors influencing effect of core diameter on measured. Compressive strength compressive load cross sectional area of the specimen grade of concrete different different sizes of aggregates 10mm,12mm,15mm minimum compressive strength nmm2 at 7 days compressive strength nmm2 at 14 days. A study of factors affecting the flexural tensile strength. The compressive strength of concrete is the most common performance measure used by the engineer in designing buildings and other structures. Factors affecting test results material parent batch of the sample wc, bleeding, segregation. Effect of superplasticizer on the compressive strength of. The results indicated an increase in the tensile and compressive strength up to a temperature of 100 c. The general rule is that the more cement you have the stronger your concrete, but too much cement also brings with it too much heat generated from hydration which will cause cracks and also retard the reaction.
The mix design parameters had a significant effect on the performance of concrete exposed to elevated temperature. What is concrete strength and what are the factors affecting it. One comment on important factors affecting the compressive strength of concrete gabriel says. The factors affecting the compressive strength of concrete are. Factors affecting strength of concrete concrete strength. Factors affecting concrete strength online civilforum. The compressive strength is measured by breaking cylindrical concrete specimens in a compressiontesting machine. Some factors influencing effect of core diameter on. Compressive strength cs of cement given are average values. The strength of the concrete can be measured with the different test that are conducted on it such as, compressive strength, tensile strength and flexural strength. The compressive strength of concrete is determined in the laboratory in controlled conditions. Concrete cubes will be tested for compressive strength.
Cip 35 testing compressive strength of concrete what is the compressive strength of concrete. Compressive strength of concrete is an important element in designing r. Computing the compressive strength of concrete cubes at 7. The ratio of the water to cement is the chief factor for determining concrete strength as shown in fig. They concluded that the concrete member size has a significant effect and proposed an equation incorporating the effect of size of concrete for predicting the flexural tensile strength of concrete given as, f r 0. Chapter cement determination of strength page 71 compressive strength is calculated from. Many factors have been shown to influence the flexural tensile strength of. Also, the degrees of workability of both concrete mixes were investigated using slump test. M international journal of civil and structural engineering volume 2 issue 3 2012 794 olanipekun, olusola, and ata 2006. In this project the effect of high rate of loading on compressive strength of concrete has been studied.
Properties of each concrete mix decide which mixtures should be used for research question different environments. Application of size effect to compressive strength of. The void ratio is to be found in range of 25% to 32%, which is sufficient for pervious concrete. Factors affecting strength and durability of concrete made with. Abramss law of compressive strength versus watercement ratio is well known and many investigators have studied the possible effects of other factors, such as cement content and sand concentration, upon concrete strength.
On the basis of this test result we judge the quality of concrete. If plasticizer is added to concrete, it will have more compressive strength after 28 days. Compressive strength is the most important property of concrete. If pavement strength is to be determined, it is suggested that indirect tensile tests should be conducted rather than estimating tensile strength from compressive or flexural tests, because of the fact that pavements fail in tension. Our results show that the postpeak behavior of the cubes is. Effect of rate of loading on compressive strength of concrete. Test for compressive strength is carried out either on cube or cylinder. The rate of strength is dependent on various factors at which the strength of concrete expands as soon as the mixing is completed. The tests were performed at a single axial strain rate, 10. Compressive strength and the chloride diffusion coefficient of concrete are considered bulk properties with a strong dependency on the porosity and pore size distribution 678.
The results show a clear dependence on specimen size. The strength of the concrete shows the ability of the structure to withstand various loads i. Voids in concrete can be filled with air or with water. The deflection and cracking behavior of concrete structure members depend on the flexural tensile strength of concrete. A study of factors affecting the flexural tensile strength of.
May 29, 2014 the effect of elevated temperature on the concrete specimens prepared with varying mixture proportions was evaluated by measuring the residual compressive and splittensile strength. Comparison between modern and classic method concrete compressive strength testing with press and rebound hammer advantages of testing the compressive strength of concrete with two methods. Size and shape effects on the compressive strength of high. N2 aerated concrete is a relatively homogeneous material as compared with conventional concrete since it is devoid of the coarse aggregate phase, yet it exhibits vast variation in its properties. Compressive strength of referral concrete as well as fly ash concrete at 7, 28 and 56 d are given in table 6 and fig. Important factors affecting the compressive strength of. The compressive strength pervious concrete showed an increase in watercement ratio increased. Sixtyfour 64 concrete cubes were cast and cured for. It is evident that beyond 28 d, the strength increased with the addition of fly ash. Key words in situ strength, concrete pavements, tensile strength, compressive tests, flexural. Compressive strength tests were performed at the ages of 7, 28, and 90 days on a total of 2268 core and cube specimens and the effect of core diameter on concrete core strength was examined. Summary abramss law of compressive strength versus watercement ratio is well known and many investigators have studied the possible.
Some factors affecting the compressive strength of. Pdf key factors affecting the compressive strength of. This study considered the effect of different methods of curing on density and compressive strength of concrete. The effect of the free water, age and curing conditions upon the strength loadingrate relationship of concrete, mortar and neat cement paste was studied. The lower the watercement ratio, the higher is the compressive strength. Although this is the theoretical limit, water cement ratio lower than 0. This data sheet has been prepared in the interest of preventing unnecessary problems and delays at construction sites occurring when test cylinders break below specified strengths, caused by. Effect of hand mixing on the compressive strength of concrete james isiwu aguwa 60 introduction simply, concrete is a structural material widely used in the construction industry. Durability is not directly related to the strength of concrete.
Influence of size of aggregates on the compressive. Factors affecting strength of concrete factors affecting concrete strength concrete strength is effected by many factors, such as quality of raw materials, watercement ratio, coarsefine aggregate ratio, age of concrete, compaction of concrete, temperature, relative humidity and curing of concrete. Some applications use higher strengths, greater than 10,000 psi 70 mpa. For the 28day compressive strength of ordinary concrete, the.
Compressive strength of concrete the strength of concrete is controlled by the proportioning of cement, coarse and fine aggregates, water, and various admixtures. Factors affecting strength test results of concrete. It appears, therefore, that other factors must be considered as affecting abrasion resistance. Witte and backstrom 7 also state that compressive strength is the most important factor controlling the abrasion resistance of concrete, abrasion resistance increasing as compressive strength increases. The compressive strength of concrete is the most common performance attribute used. Factors influencing the density and compressive strength of. Compressive strength results are used to ensure that the concrete mixture as delivered. T1 factors influencing the density and compressive strength of aerated concrete. The effect of elevated temperature on the concrete specimens prepared with varying mixture proportions was evaluated by measuring the residual compressive and splittensile strength. It is important to consider the effect of size when estimating the ultimate strength of a concrete member under various loading conditions. This further buttresses the point that the aggregates can be used for construction work. Druability is related to the performance of the concrete, i.
The following terms are associated with the strength gain of concrete. Effect of curing methods on density and compressive. Although many investigations, not only on impact compressive strength of concrete materials, but also their impact tensile strength have been reported, there does not seem to be a standard test method for impact tensile strength of concrete 47. The relative quantities of cement, aggregates and water mixed together, control the properties of concrete in wet state as well as in hardened state. Feb, 2015 concrete compressive strength requirements can vary from 2500 psi 17 mpa for residential concrete to 4000 psi 28 mpa and higher in commercial structures. However, air entrainment greatly reduces the mechanical strength 35.
Well known as the size effect, the strength of a member tends to decrease when its size increases. Effects of key factors on compressive and tensile strengths of. Five ways aggregate can affect the strength of concrete. In the long run, the compressive strength of the control concrete is the same as the 10% and 20% sf concretes. Compressive strength of concrete lifting and leading shall be done with proper care to avoid impact on. Compressive strength of concrete depends on many factors such as watercement ratio, cement strength, quality of concrete material, quality control during production of concrete etc. The cubes were cured using six methods air curing, watersubmerged curing, spray curing, polythene curing, moist sand curing and.
Many investigators24252627282930323334 reported that the compressive strength decreased because the density decreased with increasing lightweight aggregate ratio instead of the normal aggregate. We at are thankful to sir kaushal kishore for submitting this research paper and helping all civil engineers understand the concept of concrete strength and factors affecting it. From the standpoint of strength, the water cement ratio porosity relation is undoubtedly the most important. It is also demonstrated that the combination of the foaming agent with a particular watercement ratio is a crucial parameter affecting the. This value was kept constant throughout the experimental program. Structures compressive strength of concrete consequently quality of concrete manufactured is often measured by. Influence of size of aggregates on the compressive strength.
Air voids are on obvious and easily visible example of pores in concrete. What is concrete strength and what are the factors. We use cylinders and cubes of different sizes for performing stable stressstrain tests. Does the addition of plasticizer in concrete samples increase the concretes compressive strength. Size and shape effects on the compressive strength of high strength concrete j. What are some ways to increase the strength of a concrete. Effect of aggregate type on compressive strength of concrete abdullahi. Strength and workability characteristics of concrete by using different super plasticizers. The compressive strength of highperformance concrete and. Compressive strength of concrete hardened concrete 1 g. The compressive strength of pervious concrete is less than conventional concrete. This has quite similarity with setting but setting and hardening are different. Investigations have also conducted for finding the applicability of this 0.
So, the effect of aggregate contents do not seem consistent and are hard to generalize. Factors affecting strength of concrete concrete strength is affected by many factors, such as quality of raw materials, watercement ratio, coarsefine aggregate ratio, age of concrete, compaction of concrete, temperature, relative humidity and curing of concrete. Concrete compressive strength can vary from 2500 psi 17 mpa for residential concrete to 4000 psi 28 mpa and higher in commercial structures. It will be studied that flaky aggregates beyond certain limit decreases strength and workability and hence the strength of concrete greatly depends on internal structure and flakiness aggregates. A study of factors affecting the flexural tensile strength of concrete. Factors affecting concrete strength concrete strength is effected by many factors, such as quality of raw materials, watercement ratio, coarsefine aggregate ratio, age of concrete, compaction of concrete, temperature, relative humidity and curing of. False strength of concrete proves fatal as it may fail due to various factors in the long terms. Effect of fly ash on compressive strength of portland.
Introduction concrete is a composite material produced by the. The effect of the free water, age and curing conditions upon the strengthloadingrate relationship of concrete, mortar and neat cement paste was studied. Effect of aggregate flakiness on the compressive strength. Factors affecting strength of concrete concrete strength is affected by many factors, such as quality of raw materials, watercement. Founded in 1904 and headquartered in farmington hills, michigan, usa, the american concrete institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensusbased standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design. Small amounts of stress can cause irreversible deformation and flow. The splitting tensile strength is plotted as a function of the aggregate tensile strength. Prev next some factors affecting the compressive strength of concrete authors. Effect of curing methods on density and compressive strength. Therefore, in view of recent increased interest in the size effect of concrete this research focuses on the size effect of two main classes of compressive strength of concrete. Effects of watercement ratios on the compressive strength and workability of concrete and lateritic concrete mixes. The low value relates to highstrength concrete compressive strength 128 mpa and the high value to a medium strength concrete 35 mpa. Provided the cement conforms with the appropriate standard and it has been stored correctly i.
But my question is explain factors affecting tue compressive strength of concrete. There are many factors that can affect the strength of concrete. The effects of aggregate type, size, and content on the behavior of normal and highstrength concrete, and the relationships between compressive strength, flexural strength, and fracture energy are discussed. Relationship control and plasticizer compressive strength of concrete. Dead load, live load, earthquake load, wind load, etc. Factors influencing the density and compressive strength. Concrete mixtures can be designed to provide a wide range of mechanical and durability properties to meet the design requirements of a structure.
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