g QHS
(c) the setting time of cement and the amount of mixing water than on atmospheric
temperature
(d) the amount of mixing water used and the atmospheric temperature than on the
setting time of cement
- Which of the following is not an accelerator?
(a) CaCl 2 (b) CaSO 4
(c) NaCl (d) Formaldehyde
- Which of the following admixture is not a chemically inactive water proofer?
(a) Soda soaps (b) Calcium soaps
(c) Wax (d) Vegetable oils
- The role of superplasticizer in a cement paste is to
(a) disperse the particles
(b) disperse the particles and to remove air bubbles
(c) disperse the particles, remove air bubbles and to retard setting
(d) retard setting
- Consider the following statements:
The addition of surfactants in the concrete mix results in
- increase in the water cement ratio
- decrease in the water cement ratio
- increase in the strength of concrete
- decrease in the curing duration
- increase in the density of concrete
Of these statements
(a) 1, 3 and 4 are correct just (b) 2, 3 and 5 are correct
(c) 3, 4 and 5 are correct (d) 1, 4 and 5 are correct
- Match List-I (Admixtures) with List-II (Chemicals) and select correct answer using the
codes given below the lists:
List-I List-II
A. Water reducing admixture 1. Sulphonated melanin
B. Air entraining agent 2. Calcium chloride
C. Super plasticiser 3. Lignosulphonate
D. Accelerator 4. Neutralized vinsol resin
Codes:
(a)ABCD (b)ABCD
2413 1342
(c)ABCD (d)ABCD
3412 3421
- Ultrasonic pulse velocity method in used to determine
(a) compressive strength of concrete (b) impact resistance of concrete
(c) tensile strength of concrete (d) quality of concrete
- The ratio of tensile strength to compressive strength of concrete is about
(a) 1/5 (b) 1/2
(c) 1/10 (d) 1/20
