Description : Addition of pozzolana to ordinary Portland cement increases (A) Bleeding (B) Shrinkage (C) Permeability (D) Heat of hydration
Last Answer : Answer: Option B
Description : Addition of pozzolana to cement (A) Decreases workability (B) Increases strength (C) Increases heat of hydration (D) None of these
Last Answer : Answer: Option D
Description : Addition of pozzolana to ordinary port land cement, causes (A) Decrease in early strength (B) Reduction in chemical action with sulphates (C) Increase in shrinkage (D) All the above
Description : Portland pozzolana cement possesses (A) Higher resistance to chemical attack (B) Lower heat of hydration (C) Lower shrinkage on drying (D) All the above
Description : Select the incorrect statement (A) Lean mixes bleed more as compared to rich ones. (B) Bleeding can be minimized by adding pozzolana finer aggregate (C) Bleeding can be increased by addition 'of calcium chloride (D) None of the above
Description : As compared to ordinary Portland cement, use of pozzolana cement (A) Reduces workability (B) Increases bleeding (C) Increases shrinkage (D) Increases strength
Last Answer : Answer: Option C
Description : During the process of hardening of cement, _______ will takes place [ A ] Bleeding [ B ] Segregation [ C ] Hydration [ D ] All the above
Last Answer : [ C ] Hydration
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 : The cement whose strength is a little lower than the ordinary cement during the first three months but attains afterwards the same strength, is known as (A) Low-heat Portland cement (B) Rapid hardening Portland cement (C) Portland blast slag cement (D) Portland pozzolana cement
Last Answer : Answer: Option A
Description : For construction of structures in sea water, the cement generally preferred to, is (A) Portland-pozzolana cement (B) Quick setting cement (C) Low heat Portland cement (D) Rapid hardening cement
Description : The setting and hardening of cement after addition of water is due to a) Binding action of water b) Evaporation of water c) Hydration and hydrolysis of some constituent compounds of cement* d) Additional hardening compounds added to cement
Last Answer : c) Hydration and hydrolysis of some constituent compounds of cement*
Description : Percentage of pozzolanic material containing clay upto 80% used for the manufacture of pozzolana cement, is (A) 30 % (B) 40 % (C) 50 % (D) 60 %
Last Answer : (A) 30 %
Description : Pozzolana cement is used with confidence for construction of (A) Dams (B) Massive foundations (C) R.C.C. structures (D) All the above
Last Answer : (D) All the above
Description : Ordinary Portland cement is manufactured from (A) Lime stone and clay (B) Gypsum and lime (C) Pozzolana (D) Lime, pozzolana and clay
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 : Name the type of cement from the following for canal linings: (A) Sulphate resisting cement (B) Rapid hardening cement (C) Quick setting cement (D) Pozzolana cement
Description : Cement setting under water employs a/an __________ process. (A) Hydration (B) Decomposition (C) Oxidation (D) Reduction
Last Answer : (A) Hydration
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 : Pick up the incorrect statement from the following: (A) The degree of grinding of cement, is called fineness (B) The process of changing cement paste into hard mass, is known as setting of ... (D) The heat generated during chemical reaction of cement with water, is known as heat of hydration
Description : The presence of dicalcium silicate in cement. (a) Hydrates the cement slowly. (b) Generates less heat of hydration. (c) Has more resistance to sulphate attack. (d) All of these
Last Answer : (d) All of these
Description : The presence of tricalcium silicate in cement (a) Hydrates the cement rapidly (b) Generates less heat of hydration. (c) Offer high resistance to sulphate attack (d) All of these
Last Answer : (a) Hydrates the cement rapidly
Description : The heat of hydration for low heat cement at the age of 7 days shall not exceed [ A ] 80 cal / gm [ B ] 75 cal / gm [ C ] 70 cal / gm [ D ] 65 cal / gm
Last Answer : [ D ] 65 cal / gm
Description : A cobalt chloride solution soaked into a piece of cotton can be used as an indicator for changes in humidity levels. Pink indicates a high-humidity environment and blue a low-humidity environment. What ... the cobalt's waters of hydration. z) This is an illustration of the Schrodinger principle.
Last Answer : ANSWER: Y -- THE LOSS AND READSORPTION OF THE COBALT'S WATERS OF HYDRATION.
Description : Which cement should not be used for bridge slabs ro RCC frames a) OPC b) Portland Pozzolana cement * c) Portland furnace slag cement d) Rapid hardening cement
Last Answer : b) Portland Pozzolana cement *
Description : When each particle of aggregates is thinly coated with cement paste, a heterogeneous solid is formed, which is known as (A) Hydration (B) Gel (C) Concrete (D) None of these
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
Description : The condition not applicable to water cement ratio law, is (A) Internal moisture conditions on hydration continue till complete strength is gained (B) Concrete specimens may be tested at any temperature (C) Concrete specimens need be of same age (D) Concrete specimens need be of same size
Description : Pick up the correct statement from the following: (A) The concrete gains strength due to hydration of cement (B) The concrete does not set at freezing point (C) The strength of concrete increases with its age (D) All the above
Description : Pick up the correct statement from the following: (A) Water cement paste hardens due to hydration (B) During hardening cement binds the aggregates together (C) Cement provides strength, durability and water tightness to the concrete (D) All the above
Description : Concrete gains strength due to (A) Chemical reaction of cement with sand and coarse aggregates (B) Evaporation of water from concrete (C) Hydration of cement (D) All the above
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
Description : The deleterious materials present in the aggregate (a) Prevent normal hydration of cement (b) Reduce the strength and durability of concrete. (c) Modify the setting action and cause efloresecence. (d) All of the above
Last Answer : (d) All of the above
Description : Concrete gains strength due to [ A ] Chemical reaction of cement with sand and coarse aggregates [ B ] Evaporation of water from concrete [ C ] Hydration of cement [ D ] All the above
Last Answer : [ C ] Hydration of cement
Description : Which one is not an appropriate approach to control frost? a. Avoidance b. Reduction of heat loss c. Addition of heat d. Transmittance of control
Last Answer : Avoidance
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
Description : The lower water cement ratio in concrete, introduces (A) Smaller creep and shrinkage (B) Greater density and smaller permeability (C) Improved frost resistance (D) All the above
Description : For different concrete specimens, each hydrated tot he same degree, the permeability is (a) Higher with lower water cement ratio and higher cement content (b) Lower with lower water cement ratio ... ratio and lower cement content (d) Lower with higher water cement ratio and higher cement content
Last Answer : (b) Lower with lower water cement ratio and higher cement content
Description : The main factors affecting the permeability of concrete are (i)Grade of concrete (ii)Minimum cement content (iii)Maximum water cement ratio [ A ] i [ B ] i and ii [ C ] ii and iii [ D ] i, ii and iii
Last Answer : [ C ] ii and iii
Description : The maximum water content at which a reduction in water content does not cause a decrease in volume of a soil mass, is known (A) Liquid limit (B) Plastic limit (C) Shrinkage limit (D) Permeability limit
Last Answer : (C) Shrinkage limit
Description : Separation of water or water sand cement from a freshly concrete, is known (A) Bleeding (B) Creeping (C) Segregation (D) Flooding
Description : A concrete using an air entrained cement (A) Has strength less than 10% to 15% (B) Has more resistance to weathering (C) Is more plastic and workable (D) Is free from segregation and bleeding
Description : A badly mixed cement concrete results in (A) Segregation (B) Bleeding (C) Honey combing (D) None of these
Description : The separation of water or water cement mixture from the freshly laid concrete is known as [ A ] Workability [ B ] Segregation [ C ] Bleeding [ D ] Creep
Last Answer : [ C ] Bleeding
Description : What is the first stage of hydration in cement?
Last Answer : Need answer
Description : Setting of cement is due to the hydration of calcium silicates and?
Last Answer : Calcium aluminates
Description : Cement is made hard with (1) dehydration (2) hydration and dissociation of water (3) Dissociation of water (4) Polymerisation
Last Answer : hydration and dissociation of water
Description : Write the significance of water-cement ratio and its effect on hydration of cement.
Last Answer : Significance of water-cement ratio: The W/C ratio plays very vital role in concrete mixture. The improper or random selection of W/C ratio leads in various defects in fresh and hardened concrete ... of water for sufficient hydration. But such large water may not give proper binding of aggregates.
Description : Define hydration of cement
Last Answer : Hydration of cement: It is exothermic chemical reaction takes place when water is added to cement, which gives rise cement paste and large amount heat is evolved. About 120 cal/gm, heat is evolved. This is called as hydration of cement.
Description : Pozzolana (or surkhi) is used in lime (A) To impart hydraulicity (B) To prevent shrinkage (C) To decrease the cost of construction (D) To decrease the setting time