1. What is the permissible limits for construction of chlorides in water for RCC work?
a) 200mg/l
b) 2000mg/l
c) 1000mg/l
d) 500mg/l
Explanation: 1000mg/l is the standard value for the permissible limits for construction of chlorides in water for RCC work.
2. What is the permissible limits for construction of chlorides in water for PCC work?
a) 200mg/l
b) 2000mg/l
c) 1000mg/l
d) 500mg/l
Explanation: 2000mg/l is the standard value for the permissible limits for construction of chlorides in water for PCC work.
3. What is the permissible limits for construction of sulphates in water?
a) 200mg/l
b) 2000mg/l
c) 1000mg/l
d) 500mg/l
Explanation: 500mg/l is the standard value for the permissible limits for construction of sulphates in water.
4. There is necessary to minimize the use of salt water in RCC.
a) True
b) False
Explanation: Salty water causes rusting problems in the steel provided in RCC work for the structures.
5. Presence of acid, alkali ___________
a) Increases the strength
b) Reduces the strength
c) Do effect the concrete
d) Depends upon the proportion
Explanation: Presence of acid, alkali, industrial waste, sanitary sewage and water with sugar also reduce the strength of concrete.
6. What is the maximum limit (ppm) for chlorides in water?
a) 500
b) 1000
c) 2000
d) 1500
Explanation: It is the standard value of maximum limit (ppm) for chlorides in water for construction.
7. What is the maximum limit (ppm) for SO3 in water?
a) 500
b) 1000
c) 2000
d) 1500
Explanation: It is the standard value of maximum limit (ppm) for Sulphur trioxide in water for construction.
8. What is the maximum limit (ppm) for turbidity in water?
a) 500
b) 1000
c) 2000
d) 1500
Explanation: It is the standard value of maximum limit (ppm) for turbidity in water for construction.
9. What is the maximum limit (ppm) for Alkali Carbonates and Bicarbonates in the water?
a) 500
b) 1000
c) 2000
d) 1500
Explanation: It is the standard value of maximum limit (ppm) for Alkali Carbonates and Bicarbonates in water for construction.
10. What do you mean by admixtures?
a) Ingredients which are added to in cement before or after concrete mix
b) Ingredients which are added to make aggregates healthier
c) Ingredients added in cement to make it shinier
d) Ingredients added in concrete to make good workability
Explanation: Admixtures are those ingredients in concrete other than Portland cement, water, and aggregates that are added to the mixture immediately before or after the concrete mix.