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
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
The maximum quantity of calcium chloride used as an accelerator in cement in percentage by weight of cement is_______________?
(A) 1
(B) 2
(C) 3
(D) 4
Which of the following cements is suitable for use in massive concrete structures such as large dams ?
(A) ordinary Portland cement
(B) low heat cement
(C) rapid hardening cement
(D) sulphate resisting cement
For testing compressive and tensile strength of cement, the cement mortar is made by mixing cement and standard sand in the proportions of___________________?
(A) 1:2
(B) 1:3
(C) 1:4
(D) 1:6
Gypsum consists of______________?
(A) H2S and C02
(B) CaS04 and H20
(C) Lime and H20
(D) C02 and calcium
The normal consistency of ordinary Portland cement is about________________?
(A) 10%
(B) 20%
(C) 30%
(D) 40%
After storage, the strength of cement________________?
(A) decreases
(B) increases
(C) remains same
(D) may increase or decrease
The slump recommended for mass concrete is about_______________?
(A) 25 mm to 50 mm
(B) 50 mm to 100 mm
(C) 100 mm to 125 mm
(D) 125 mm to 150 mm
Addition of pozzolana to ordinary Portland cement increases__________________?
(A) bleeding
(B) shrinkage
(C) permeability
(D) heat of hydration