Description : The main constituent of cement which is responsible for initial setting of cement is (A) Di-calcium silicate (B) Tri-calcium silicate (C) Tri-calcium aluminate (D) All of the above
Last Answer : Answer: Option C
Description : Initial setting of cement is caused due to (A) Tri-calcium silicate (B) Di-calcium silicate (C) Tri-calcium aluminate (D) Tetra calcium alumino ferrite
Description : Pick up the compound responsible for early strength of cement from the following: (A) Tetra-calcium alumino-ferrite (B) Tri-calcium silicate (C) Tri-calcium aluminate (D) Di-calcium silicate
Last Answer : Answer: Option B
Description : The constituent of cement which is responsible for all the undesirable properties of cement is (A) Di-calcium silicate (B) Tri-calcium silicate (C) Tri-calcium aluminate (D) Tetra calcium alumino ferrite
Description : The compound of Portland cement which reacts immediately with water and also sets first is (A) Tri-calcium silicate (B) Di-calcium silicate (C) Tri-calcium aluminate (D) Tetra calcium alumino ferrite
Description : The compound of Portland cement which contributes to the strength after two to three years is (A) Tri-calcium silicate (B) Di-calcium silicate (C) Tri-calcium aluminate (D) Tetra-calcium alumino ferrite
Description : In the cement the compound quickest to react with water, is (A) Tri-calcium aluminate (B) Tetra-calcium alumino-ferrite (C) Tri-calcium silicate (D) Di-calcium silicate
Last Answer : Answer: Option A
Description : Good quality cement contains higher percentage of (A) Tri-calcium silicate (B) Di-calcium silicate (C) Tri-calcium aluminate (D) Tetra calcium alumino ferrite
Description : Ultimate strength to cement is provided by (A) Tri-calcium silicate (B) Di-calcium silicate (C) Tri-calcium aluminate (D) Tetra calcium alumino ferrite
Description : Rapid hardening cement contains (A) Tri-calcium silicate (B) Tri-calcium aluminate (C) Tetra-calcium alumino-ferrite (D) Di-calcium silicate
Description : Early attainment of strength in rapid hardening cement is mainly due to (A) Gypsum (B) Finer grinding (C) Tri-calcium silicate (D) Tri-calcium aluminate
Description : The first compound which reacts with water when mixed with cement is (a) Tricalcium Aluminate (b) Tricalcium silicate (c) Di-calcium silicate (d) Teracalcium aluminate
Last Answer : (a) Tricalcium Aluminate
Description : A slow setting cement will have higher percentage of a) tricalcium aluminate b) tricalcium silicate c) Gypsum d) Dicalcium silicate*
Last Answer : C2s
Description : Main constituents of Portland cement are calcium aluminate and (A) Gypsum (B) Silicates (C) Sodium silicate (D) Carbonates
Last Answer : (B) Silicates
Description : Pick out the wrong statement. (A) High early strength cement are made from materials having high silica to lime ratio (B) The function of gypsum in cement is to enhance its initial ... cements are known as silicate cement (D) Major component of greyish Portland cement is tricalcium silicate
Last Answer : (A) High early strength cement are made from materials having high silica to lime ratio
Description : About 70% to 80% of cement is contributed by [ A ] Tricalcium silicate and Tricalcium aluminate [ B ] Tricalcium silicate and Dicalcium silicate [ C ] Tricalcium Aluminate and Dicalcium silicate [ D ] Tricalcium Aluminate and Tetra calcium Aluminoferrite
Last Answer : [ B ] Tricalcium silicate and Dicalcium silicate
Description : Di-calcium silicate (C2S) (A) Hydrates rapidly (B) Generates less heat of hydration (C) Hardens rapidly (D) Provides less ultimate strength to cement
Description : Tricalcium aluminate (C3A) (A) Reacts fast with water (B) Generates less heat of hydration (C) Causes initial setting and early strength of cement (D) Does not contribute to develop ultimate strength
Description : Finely ground calcium aluminate & silicate is a/an (A) Cermet (B) Cement (C) Abrasive (D) Explosive
Last Answer : (B) Cement
Description : Cement is usually a mixture of : (1) Calcium silicate and calcium aluminate (2) Calcium silicate and calcium ferrate (3) Calcium aluminate and calcium ferrate (4) Lime stone and silicon dioxide
Last Answer : Calcium silicate and calcium aluminate
Description : The most commonly used admixture which prolongs the setting and hardening time is (A) Gypsum (B) Calcium chloride (C) Sodium silicate (D) All of the above
Last Answer : (A) Gypsum
Description : Hydration of cement is due to chemical action of water with (A) Tricalcium silicate and dicalcium silicate (B) Dicalcium silicate and tricalcium aluminate (C) Tricalcium aluminate and tricalcium alumino ferrite (D) All the above
Last Answer : Answer: Option D
Description : Hydration of cement is due to the chemical action of water with. (a) Tricalcium silicate (b) Dicalcium silicate (c) Tricalcium aluminate (d) All of these
Last Answer : (d) All of these
Description : The gypsum is added to the cement for (a) Providing high strength to the cement (b) Controlling the initial setting time of cement. (c) Lowering the clinkering temp of cement (d) All the above.
Last Answer : (b) Controlling the initial setting time of cement.
Description : The development of first 28 days strength is on account of the hydration of (a) Tricalcium silicate (b) Dicalcium silicate (c) Tricalcium aluminate (d) Tetra calcium alumina ferrite
Last Answer : (a) Tricalcium silicate
Description : Setting time of cement increases by adding (A) Gypsum (B) Hydrogen peroxide (C) Calcium chloride (D) Sodium oxide
Description : Setting time of cement increases by adding (i)gypsum (ii)sodium oxide (iii)calcium chloride [ A ] i [ B ] i and ii [ C ] i and iii [ D ] i, ii and iii
Last Answer : [ A ] i
Description : The constituent of cement which act as Binders are a) Sand and silica b) Silica and carbon c) tricalcium silicate dicalcium silicate and carbon d) tricalcium aluminate,dicalcium silicate and tricalcium silicate *
Last Answer : d) tricalcium aluminate,dicalcium silicate and tricalcium silicate *
Description : The Most common admixture used to accelerate the initial setting of concrete is a) Gypsum b) Calcium chloride* c) Calcium carbonate d) Calcium bicarbonate
Last Answer : b) Calcium chloride*
Description : Which substance is used to retard the setting action of cement?
Last Answer : CaSO.2HO
Description : 1. What is the study of principles and procedures of classification? 2. Who appoints the Governor of Jammu and Kashmir? 3. Which substance is used to retard the setting action of cement? 4. ... . What is the minimum forest cover to maintain ecological balance? 20. Which saint wrote Bijak' ?
Last Answer : Answer : 1. Taxonomy 2. President 3. CaSO.2HO 4. Indus 5. Bhaskara 6. Capital expenditure 7. Peru 8. K. C. Mehta 9. Brahmaputra 10. Bukka I 11. Governor 12. Centrifugal force 13. Japan 14. Hurricane 15. Hasan 16. National Development Council 17. 4 18. 25 years 19. 33% 20. Kabir
Description : Heating of __________ to 120°C, produces plaster of paris. (A) Blue vitriol (B) Gypsum (C) Calcium silicate (D) Calcium sulphate
Last Answer : (B) Gypsum
Description : Quick setting cement is produced by adding (A) Less amount of gypsum in very fine powdered form (B) More amount of gypsum in very fine powdered form (C) Aluminium sulphate in very fine powdered form (D) Pozzolana in very fine powdered form
Description : The pH value of water is kept slightly less than 7 so that hydrochloride ions may combine with ammonia ions to form (A) Mono-chloramine (NHCl) (B) Di-chloramine (NH2Cl) (C) Nitrogen tri-chloramine (NCl3) (D) All the above
Last Answer : (D) All the above
Description : The most common admixture which is used to accelerate the initial set of concrete is (A) Gypsum (B) Calcium chloride (C) Calcium carbonate (D) None of the above
Description : The most commonly used retarder in cement is (A) Gypsum (B) Calcium chloride (C) Calcium carbonate (D) None of the above
Description : Pick out the wrong statement. (A) Dry process is used for the manufacture of cement, when the raw material is blast furnace slag (B) Portland cement is made employing wet process (C) Gypsum is added to Portland cement to lengthen its setting time (D) None of these
Last Answer : (D) None of these
Description : For an ordinary Portland cement (A) Residual does not exceed 10% when sieved through IS Sieve No. 9 (B) Soundness varies from 5 to 10 mm (C) Initial setting time is not less than 30 minutes (D) Compressive stress after 7 days, is not less than 175 kg/cm2
Last Answer : (C) Initial setting time is not less than 30 minutes
Description : As compared to ordinary Portland cement, high alumina cement has (A) Higher initial setting time but lower final setting time (B) Lower initial setting time but higher final setting time (C) Higher initial and final setting times (D) Lower initial and final setting times
Description : Pick up the correct statement regarding low heat cement from the following: (A) It possesses less compressive strength (B) Its initial setting time is about one hour (C) Its final setting time is about 10 hours (D) All the above
Description : Initial setting time of cement for asbestos cement products should be not less than (A) 30 minutes (B) 50 minutes (C) 75 minutes (D) 90 minutes
Description : The initial setting time for ordinary Portland cement as per IS specifications should not be less than (A) 10 minutes (B) 30 minutes (C) 60 minutes (D) 600 minutes
Description : The basic purpose of a retarder in concrete is (A) To increase the initial setting time of cement paste in concrete (B) To decrease the initial setting time of cement paste in concrete (C) To render the concrete more water tight (D) To improve the workability of concrete mix
Description : If ‘W’ is the percentage of water required for normal consistency of cement, water to be added for determination of initial setting time is (a) 0.50 W (b) 0.62 W (c) 0.75 W (d) 0.85 W
Last Answer : (d) 0.85 W
Description : According to IS Code , the requirement of an ordinary Portland cement is (a) The residue does not exceed 10% when sieved through is sieve no .9 (b) Its initial setting time is not less than 30 minutes. (c) its expansion is not morethan 10mm for unaerated cement (d) All the above.
Last Answer : (d) All the above.
Description : (1) Calcium silicate and calcium alurninate Explanation: Portland cement is the most common type of cement in general use around the world because it is a basic ingredient of concrete, mortar, stucco ... limited amount of calcium sulfate (which controls the set time) and up to 5% minor constituents.
Last Answer : Milk is a colloidal system in which: (1) Water is dispersed in fat (2) Fat is dispersed in water (3) Fat and water are dispersed in each other (4) Fat is dissolved
Description : How does the setting of cement takes place & what is the role of gypsum in setting of cement ?
Last Answer : Ans When mixed with water, the setting of cement takes place to give a hard mass. This is due to the hydration of the molecules of the constituents and their Rearrangement. The purpose of adding gypsum is only to slow down the process of setting of the cement so that it gets sufficiently hardened.
Description : The function of gypsum addition during cement making is to (A) Increase the density of cement (B) Decrease the cement setting rate (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (B) Decrease the cement setting rate
Last Answer : When mixed with water, the setting of cement takes place to give a hard mass. This is due to the hydration of the molecules of the constituents and their rearrangement. The purpose of adding gypsum is only to slow down the process of setting of the cement so that it gets sufficiently hardened.
Description : The addition of gypsum to portland cement helps in : (1) increasing the strength of cement (2) rapid setting of cement (3) preventing rapid setting of cement (4) reduction in the cost of cement
Last Answer : preventing rapid setting of cement