3.4.8 Soundness – The soundness test determines an aggregate’s resistance to disintegration by weathering and, in particular, freeze–thaw cycles ( AASHTO T 104, 2003 and ASTM C88, 2013 ). The test is carried out by repeated immersion in a saturated solution of sodium or magnesium sulphate followed by oven drying to partially or completely dehydrate the salts precipitated in the permeable pore space.
The data available ( Gorai et al., 2003; Shi et al., 2008; Song, 2013 ) suggest that the reported soundness measurements of 0.8–0.9% for CS are well below the maximum permissible limits of 15–25% for hot mix asphalt surface course, structural concrete made with marine limestone ( BS EN 12620:2002+A1, 2008; BS EN 13242:2002+A1, 2007; SCDOT, 2011 ).
Thus, it may be concluded that CS is a perfectly sound material for use in construction. Read full chapter URL: https://www.sciencedirect.com/science/article/pii/B9780081009864000031
- 1 Why is soundness of aggregate important?
- 2 What is the meaning of soundness of cement *?
- 3 What is the final setting time of cement?
Why do we need to find soundness?
Why do we need to find soundness? Explanation: Soundness Test on Cement. Soundness Test onCement is carried out to detect the presence of uncombined lime in cement.4.
What are the major causes of soundness in cement?
01. Excess Lime – Soundness of cement is affected by the presence of excess lime (CaO) in the cement. This excess lime hydrates very slowly and forms slaked lime that occupies a larger volume than the original free calcium oxide. The slow hydration process, therefore, affects the properties of hardened concrete.
Why is soundness of aggregate important?
The soundness of aggregates to physical changes caused by the environment is important to the long-term durability characteristics of concrete. Excessive changes in volume can be caused by freezing and thawing, thermal changes at temperatures greater than freezing, and cycles of wetting and drying. Hydrometers and Wire Baskets see Laboratory Equipment Section.
What is the meaning of soundness of cement *?
Basic Civil Engineering Questions and Answers – Properties of Cement This set of Basic Civil Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Properties of Cement”.1. Why is natural cement used very limitedly? a) Brown in Colour b) Standard consistency is not met with c) Sets too quickly d) Particle size is too fine View Answer Answer: c Explanation: Natural cement sets very quickly after the addition of water and hence it is not quite workable.
- Artificial cement is preferred over this.2.
- Who invented Portland cement and in which year? a) William Aspdin, 1824 b) William Aspdin, 1840s c) Joseph Aspdin, 1840s d) Joseph Aspdin, 1824 View Answer Answer: b Explanation: Joseph Aspdin patented Portland cement in 1824.
- William Aspdin, his son is regarded as the inventor of modern Portland cement due to his developments in 1840s.3.
What is the average particle size of cement? a) 15 microns b) 45 microns c) 75 microns d) 100 microns View Answer Answer: a Explanation: Approximately 95% of cement particles are smaller than 45 microns and the average particle size is 15 microns. Note: Join free Sanfoundry classes at or 4.
- What is the meaning of soundness of cement? a) Ability to flow when mixed b) Ability to make ringing noise when struck c) Ability to form strong and sound structure d) Ability to retain volume after setting.
- View Answer Answer: d Explanation: When cement paste hardens and sets, it should not undergo any volume change.
Soundness ensures this and is tested using Autoclave expansion test.5. Time elapsed from the instance of adding water until paste ceases to behave as fluid is called: a) Initial setting time b) Final setting time c) Intermediate setting time d) Absolute setting time View Answer Answer: a Explanation: Final setting time is the time required for cement paste to reach a certain state of hardness.
- Option c and d does not exist.
- Take Now! 6.
- Which of the below mentioned is not a result of field test performed on cement? a) There should not be any lumps b) It should feel cold when you put your hand in bag of cement c) The colour should be blackish grey d) It should not be gritty when rubbed with finger View Answer Answer: c Explanation: The colour of cement is normally grey with a greenish tint.
There are different shades – lighter and darker, but it does not go as dark as blackish grey.7. Which equipment is used to test the setting time of cement? a) Core cutter b) Vibrator c) Universal testing machine (UTM) d) Vicat apparatus View Answer Answer: d Explanation: Core cutter is used to determine dry density of soil.
- Vibrator is used in sieve analysis.
- UTM can be used to test various parameters – tension, bending, shear of various materials.
- Vicat apparatus consists of a needle, used to penetrate the cement paste sample.8.
- What is the initial setting time of cement? a) 1 hour b) 30 minutes c) 15 minutes d) 30 hours View Answer Answer: b Explanation: As per IS code 4031-part 5, the initial setting time of cement is minimum of 30 minutes.
After this cement will start losing its plasticity and will not be workable.9. Use of coarser cement particles leads to: a) Low durability b) Higher strength c) Low consistency d) Higher soundness View Answer Answer: a Explanation: For coarser particles, hydration starts on the surface of particles, hence, it might not be completely hydrated.
This causes low strength and low durability.10. Wet cement can cause severe skin burns if not washed off with water immediately. a) True b) False View Answer Answer: a Explanation: Cement is highly alkaline and setting process is exothermic. Wet cement is strongly caustic and causes skin burns. Similarly, dry cement causes eye or respiratory irritation, when it comes in contact with mucous membranes.11.
Green cement is: a) Green coloured cement b) Cement mixed with plant products c) Cement mixed with recycled materials d) Cement mixed with green algae View Answer Answer: c Explanation: Green cement is a cementitious material which employs the use of optimized recycled materials.
- These can meet or even exceed the functional performance of Portland cement.12.
- What is the depth the needle in Vicat apparatus should penetrate into the cement paste in consistency test? a) 33-35 cm from bottom of the mould b) 33-35 mm from top of the mould c) 33-35 cm from top of the mould d) 33-35 mm from bottom of the mould View Answer Answer: b Explanation: The best procedure has been clearly mentioned in IS 4031 Part 4.
According to the code, 33-35mm depth of penetration is ideal. Sanfoundry Global Education & Learning Series – Basic Civil Engineering. To practice all areas of Basic Civil Engineering,, Next Steps:
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What is soundness reasoning?
Definition – In deductive reasoning, a sound argument is an argument that is valid and all of its premises are true (and as a consequence its conclusion is true as well). An argument is valid if, assuming its premises are true, the conclusion must be true.
An example of a sound argument is the following well-known syllogism : (premises) All men are mortal. Socrates is a man. (conclusion) Therefore, Socrates is mortal. Because of the logical necessity of the conclusion, this argument is valid; and because the argument is valid and its premises are true, the argument is sound.
However, an argument can be valid without being sound. For example: All birds can fly. Penguins are birds. Therefore, penguins can fly. This argument is valid as the conclusion must be true assuming the premises are true. However, the first premise is false.
Why is validity soundness important?
A deductive argument is said to be valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false. Otherwise, a deductive argument is said to be invalid, A deductive argument is sound if and only if it is both valid, and all of its premises are actually true,
- Otherwise, a deductive argument is unsound.
- According to the definition of a deductive argument (see the Deduction and Induction ), the author of a deductive argument always intends that the premises provide the sort of justification for the conclusion whereby if the premises are true, the conclusion is guaranteed to be true as well.
Loosely speaking, if the author’s process of reasoning is a good one, if the premises actually do provide this sort of justification for the conclusion, then the argument is valid, In effect, an argument is valid if the truth of the premises logically guarantees the truth of the conclusion.
The following argument is valid, because it is impossible for the premises to be true and the conclusion nevertheless to be false: Elizabeth owns either a Honda or a Saturn. Elizabeth does not own a Honda. Therefore, Elizabeth owns a Saturn. It is important to stress that the premises of an argument do not have actually to be true in order for the argument to be valid.
An argument is valid if the premises and conclusion are related to each other in the right way so that if the premises were true, then the conclusion would have to be true as well. We can recognize in the above case that even if one of the premises is actually false, that if they had been true the conclusion would have been true as well.
Consider, then an argument such as the following: All toasters are items made of gold. All items made of gold are time-travel devices. Therefore, all toasters are time-travel devices. Obviously, the premises in this argument are not true. It may be hard to imagine these premises being true, but it is not hard to see that if they were true, their truth would logically guarantee the conclusion’s truth.
It is easy to see that the previous example is not an example of a completely good argument. A valid argument may still have a false conclusion. When we construct our arguments, we must aim to construct one that is not only valid, but sound, A sound argument is one that is not only valid, but begins with premises that are actually true,
- The example given about toasters is valid, but not sound.
- However, the following argument is both valid and sound: In some states, no felons are eligible voters, that is, eligible to vote.
- In those states, some professional athletes are felons.
- Therefore, in some states, some professional athletes are not eligible voters.
Here, not only do the premises provide the right sort of support for the conclusion, but the premises are actually true. Therefore, so is the conclusion. Although it is not part of the definition of a sound argument, because sound arguments both start out with true premises and have a form that guarantees that the conclusion must be true if the premises are, sound arguments always end with true conclusions.
It should be noted that both invalid, as well as valid but unsound, arguments can nevertheless have true conclusions. One cannot reject the conclusion of an argument simply by discovering a given argument for that conclusion to be flawed. Whether or not the premises of an argument are true depends on their specific content,
However, according to the dominant understanding among logicians, the validity or invalidity of an argument is determined entirely by its logical form, The logical form of an argument is that which remains of it when one abstracts away from the specific content of the premises and the conclusion, that is, words naming things, their properties and relations, leaving only those elements that are common to discourse and reasoning about any subject matter, that is, words such as “all,” “and,” “not,” “some,” and so forth.
One can represent the logical form of an argument by replacing the specific content words with letters used as place-holders or variables. For example, consider these two arguments: All tigers are mammals. No mammals are creatures with scales. Therefore, no tigers are creatures with scales. All spider monkeys are elephants.
No elephants are animals. Therefore, no spider monkeys are animals. These arguments share the same form: All A are B; No B are C; Therefore, No A are C. All arguments with this form are valid. Because they have this form, the examples above are valid. However, the first example is sound while the second is unsound, because its premises are false.
- Now consider: All basketballs are round.
- The Earth is round.
- Therefore, the Earth is a basketball.
- All popes reside at the Vatican.
- John Paul II resides at the Vatican.
- Therefore, John Paul II is a pope.
- These arguments also have the same form: All A’s are F; X is F; Therefore, X is an A.
- Arguments with this form are invalid.
This is easy to see with the first example. The second example may seem like a good argument because the premises and the conclusion are all true, but note that the conclusion’s truth isn’t guaranteed by the premises’ truth. It could have been possible for the premises to be true and the conclusion false.
- This argument is invalid, and all invalid arguments are unsound.
- While it is accepted by most contemporary logicians that logical validity and invalidity is determined entirely by form, there is some dissent.
- Consider, for example, the following arguments: My table is circular.
- Therefore, it is not square shaped.
Juan is a bachelor. Therefore, he is not married. These arguments, at least on the surface, have the form: x is F; Therefore, x is not G. Arguments of this form are not valid as a rule. However, it seems clear in these particular cases that it is, in some strong sense, impossible for the premises to be true while the conclusion is false.
However, many logicians would respond to these complications in various ways. Some might insist–although this is controverisal–that these arguments actually contain implicit premises such as “Nothing is both circular and square shaped” or “All bachelors are unmarried,” which, while themselves necessary truths, nevertheless play a role in the form of these arguments.
It might also be suggested, especially with the first argument, that while (even without the additional premise) there is a necessary connection between the premise and the conclusion, the sort of necessity involved is something other than “logical” necessity, and hence that this argument (in the simple form) should not be regarded as logically valid.
- Lastly, especially with regard to the second example, it might be suggested that because “bachelor” is defined as “adult unmarried male”, that the true logical form of the argument is the following universally valid form: x is F and not G and H; Therefore, x is not G.
- The logical form of a statement is not always as easy to discern as one might expect.
For example, statements that seem to have the same surface grammar can nevertheless differ in logical form. Take for example the two statements: (1) Tony is a ferocious tiger. (2) Clinton is a lame duck. Despite their apparent similarity, only (1) has the form “x is a A that is F.” From it one can validly infer that Tony is a tiger.
One cannot validly infer from (2) that Clinton is a duck. Indeed, one and the same sentence can be used in different ways in different contexts. Consider the statement: (3) The King and Queen are visiting dignitaries. It is not clear what the logical form of this statement is. Either there are dignitaries that the King and Queen are visiting, in which case the sentence (3) has the same logical form as “The King and Queen are playing violins,” or the King and Queen are themselves the dignitaries who are visiting from somewhere else, in which case the sentence has the same logical form as “The King and Queen are sniveling cowards.” Depending on which logical form the statement has, inferences may be valid or invalid.
Consider: The King and Queen are visiting dignitaries. Visiting dignitaries is always boring. Therefore, the King and Queen are doing something boring. Only if the statement is given the first reading can this argument be considered to be valid. Because of the difficulty in identifying the logical form of an argument, and the potential deviation of logical form from grammatical form in ordinary language, contemporary logicians typically make use of artificial logical languages in which logical form and grammatical form coincide.
In these artificial languages, certain symbols, similar to those used in mathematics, are used to represent those elements of form analogous to ordinary English words such as “all”, “not”, “or”, “and”, and so forth. The use of an artificially constructed language makes it easier to specify a set of rules that determine whether or not a given argument is valid or invalid.
Hence, the study of which deductive argument forms are valid and which are invalid is often called “formal logic” or “symbolic logic.” In short, a deductive argument must be evaluated in two ways. First, one must ask if the premises provide support for the conclusion by examing the form of the argument.
- If they do, then the argument is valid.
- Then, one must ask whether the premises are true or false in actuality.
- Only if an argument passes both these tests is it sound,
- However, if an argument does not pass these tests, its conclusion may still be true, despite that no support for its truth is given by the argument.
Note: there are other, related, uses of these words that are found within more advanced mathematical logic. In that context, a formula (on its own) written in a logical language is said to be valid if it comes out as true (or “satisfied”) under all admissible or standard assignments of meaning to that formula within the intended semantics for the logical language.
Moreover, an axiomatic logical calculus (in its entirety) is said to be sound if and only if all theorems derivable from the axioms of the logical calculus are semantically valid in the sense just described. For a more sophisticated look at the nature of logical validity, see the articles on ” Logical Consequence ” in this encyclopedia.
The articles on ” Argument ” and ” Deductive and Inductive Arguments ” in this encyclopedia may also be helpful.
What are the two criteria for soundness?
On the other hand, a sound argument DOES need to have true premises and a true conclusion: Soundness: An argument is sound if it meets these two criteria: (1) It is valid. (2) Its premises are true. In other words, a sound argument has the right form AND it is true.
Why fineness modulus is required?
3.4.3 Fineness Modulus – The significance of fineness modulus (FM) is in specifying the proportions of fine and coarse aggregates when designing concrete mixes. The higher the value of FM, the coarser the aggregate. Generally, a lower FM results in more paste, making the concrete easier to finish.
- However, FM does not define the grading curve and different gradings could have similar FMs ( Suprenant, 1994 ).
- The obtained results for FM for the different CSs as reported in the literature have been summarized and are presented in Table 3.6,
- This shows that the range of FM for the air-cooled CS is wider than that of the quenched and the spent CS, reflecting the variability of different size fractions that air-cooled CS can have compared to the other two CS types.
In addition, the FM results of spent CS indicate that the material possesses a finer fraction than in the case of the quenched CS. Additionally, a very large number of studies did not provide information regarding the cooling process applied to the slags tested, and the materials show a broad range of FM, and as such it would be difficult to come to any specific conclusions about such results.
|Copper Slag||Fineness Modulus||References|
|Air cooled||3.47–4.90||3.66||Arivalagan (2013), Brindha et al. (2010), Brindha and Nagan 2011, Gaud et al. (2013), Gupta et al. (2012b), Rajaselvi and Beatrice (2015), Karthick et al. (2014), and Sathya and Shanmugavalli (2014)|
|Quenched||2.20–3.40||3.07||Boakye et al. (2013), Boakye (2014), Nataraja et al. (2014a,b), and Shoya et al. (1999)|
|Spent||1.78–2.00||1.84||Resende et al. (2008) and Wu et al. (2010a,b)|
|Unidentified||2.08–8.01||3.31||Ayano and Sakata (2000), Gowda and Balakrishna (2014), Hosokawa et al. (2004), Hwang and Laiw (1989), Jaivignesh and Gandhimathi (2015), Khan et al. (2015), Kharade et al. (2013), Kumar (2012), Lee (2008), Leema and Suganya (2015), Patil (2015), Madhu and Venkataratnam (2015), Mahmood and Hashmi (2014), Meenakashi and Ilangovan (2011), Saxena (2015a), Priyanka and Thahira (2013), Resende et al. (2008), Sabarishri et al. (2015), Sakthieswaran and Ganesan (2014), Shoya et al. (1997), Sudarvizhi and Ilangovan 2012, Suresh et al. (2013), and Vamsi et al. (2013)|
Read full chapter URL: https://www.sciencedirect.com/science/article/pii/B9780081009864000031
What is the average particle size of cement?
15.6.3 Water-reducing effect of fly ash – As has already been noted, the use of fly ash as an admixture in the manufacture of concrete reduces the water requirement to obtain a given consistency. There are two schools of thought as to how this actually occurs: 1.
- The size of fly ash particles, along with their smooth surface and spherical shape, allows higher particle packing density, leading to a reduction in water requirements.
- Portland cement particles are generally in the range of 1–50 micrometre (μm) while fly ash particles are usually much finer with the average size in bituminous fly ashes being in the range of 7–12 μm.28 Figure 15.15 29 taken from an actual power station coal trail programme illustrates the fineness with 79.2% being under 45 μm.
Fine cement particles do not play the same void-filling role as they tend to dissolve in water whereas fly ash particles will not dissolve in water. 15.15, Example of power station fly ash fineness.2. The effect of fly ash on water requirements comes about through adsorption-dispersion mechanisms. In this case, very fine particles of fly ash get absorbed on the oppositely-charged surface of cement particles and prevent them from undergoing flocculation.
What is the final setting time of cement?
2 The Setting Time – The setting time of cement includes the initial setting time and the final setting time, The initial time refers to the time that cement turns into paste by mixing with water and begins to lose its plasticity. And the time that cement completely loses its plasticity by mixing with water and begins to have a certain structural strength is known as the final setting time.
- The national standards prescribe that the initial setting time of Portland cement should not be earlier than 45 min and the final setting time should not be later than 6.5 h.
- All the products off-grade at the initial setting time are spoiled products and those unqualified at the final setting time are sub-quality products.
The setting time of cement is measured by time determinator. The sample is the standard cement paste of which the temperature is 20 °C ± 3 °C and humidity is more than 90%. Various mineral components of the cement clinker are different in the water consumption of their normal consistency.
The finer the cement is ground, the more water the normal consistency will need. The normal consistency of Portland cement is within 24% ~ 30%. The setting time of cement is very important in the construction projects. The initial setting time should not be too fast in order to ensure that there is enough time to complete every process, such as casting, before the initial setting time; and the final setting time should not be too late in order to enable the cement to complete its setting and hardening as soon as possible after pouring and tamping to make the next process occur earlier.
Read full chapter URL: https://www.sciencedirect.com/science/article/pii/B9781845699550500049
What is the opposite of soundness?
the quality of being sensible; the fact that something can be relied on and will probably give good results. soundness of judgement. financial soundness opposite unsoundness (1)
Why is the soundness test conducted and what is its value?
In the soundness test a specimen of hardened cement paste is boiled for a fixed time so that any tendency to expand is speeded up and can be detected. Soundness means the ability to resist volume expansion.
What is the significance of soundness of aggregate particles and describe how it is assessed?
Overview – The soundness test determines an aggregate ‘s resistance to disintegration by weathering and, in particular, freeze-thaw cycles. Aggregates that are durable (resistant to weathering) are less likely to degrade in the field and cause premature HMA pavement distress and potentially, failure.
The soundness test repeatedly submerges an aggregate sample in a sodium sulfate or magnesium sulfate solution. This process causes salt crystals to form in the aggregate’s water permeable pores. The formation of these crystals creates internal forces that apply pressure on aggregate pores and tend to break the aggregate (Figure 1).
After a specified number of submerging and drying repetitions, the aggregate is sieved to determine the percent loss of material. Figure 1: Aggregate before (top) & after (bottom) the soundness test. The formation of salt crystals is supposed to mimic the formation of ice crystals in the field and could therefore be used as a surrogate to predict an aggregate’s freeze-thaw performance. The standard soundness test is:
AASHTO T 104 and ASTM C 88: Soundness of Aggregate by Use of Sodium Sulfate or Magnesium Sulfate
What is the soundness of a property?
The soundness of a material is the ability of the material to retain its volume after hardening without excess expansion. Now coming to the soundness of concrete, Concrete is made up of cement, aggregates, water and admixtures. Of this, only cement has expansive properties.
- Therefore soundness of concrete is can be related to the soundness of cement.
- This expansive behavior is caused due to excess lime in the cement.
- The excess lime CaO hydrates very slowly to form slaked lime.
- This slaked lime is higher in volume than the initial lime.
- This causes volume changes and results in high volume.
The same phenomenon can be observed in the cement having high traces of the magnesium oxide. The excess volume may also be caused by the sulfate attack where the sulfate components in the cement react with the environment to produce calcium sulphoaluminate, which is very high in volume.
What is a soundness test in welding?
13-13. ACID ETCH TEST – a. This test is used to determine the soundness of a weld. The acid attacks or reacts with the edges of cracks in the base or weld metal and discloses weld defects, if present. It also accentuates the boundary between the base and weld metal and, in this manner, shows the size of the weld which may otherwise be indistinct.