ADAMA SCIENCE AND TECHNOLOGY UNIVERSITY
SCHOOL OF CIVIL ENGINEERING AND ARCHITECTURE
DEPARTMENT OF CIVIL ENGINEERING
9. Concrete gains its strength due to:
A.Chemical reaction of cement with sand and coarse aggregate.
B. Evaporation of water from the concrete.
C. Hydration of cement paste.
D. All of the above.
10. The property of fresh concrete in which the aggregate separates from the paste is
A. Bleeding
B.Segregation
C. Honey comb
D. Bulking
11. Imagine you are constructing a slab for a building in a cold climate and there is a lack of form-work supplies. You want to remove the form-work sooner than anticipated to speed up the building'sconstruction. Therefore,what kind of cement would you use so that the slab attains its strength sooner?
A. Sulfate resisting Portland cement
B. Rapid hardening Portland cement
C. Ordinary Portland cement
D. Low-heat Portland coment
12.As water to cement( \( \mathrm{w} / \mathrm{c} \) )ratio decreases keeping other things constant
A. The workability of concrete increases.
B. The compressive strength and durability of concrete decrease
C. The compressive strength and durability of concrete increase.
D. The workability of concrete remains unaffected.
1 \( \square \) ype of Portland cement compound which is responsible for the initial settin time,high heat of hydration,and has a greater tendency to volume changing causing cracking:
A.Tri-Calcium Silicate
B. Tn-Calcium Aluminate
C. Di-Calcium Silicate
D. Tetra Calcium Alumino Ferrite
