UNIVERSITY OF CALIFORNIA AT BERKELEY DEPARTMENT OF CIVIL ENG. SPRING SEMESTER, 1996 Instructor : P.J. M. Monteiro Name:_____________________ CE 165 - EXAMINATION Question 1 (18 points) Briefly explain the following terms which are commonly used in concrete construction practice: floating, retempering, screeding, laitance, honeycombs. Question 2 (18 points) (I) Briefly describe the mechanism of action, and side effects if any when a larger than recommended dosage of air-entraining admixture is used in a concrete. (II) Briefly describe the two stages of consolidation of concrete by vibration. List the kind of imperfections that may arise as a result of ineffective vibration. (III) In regard to their water-reducing ability, what is the difference between normal and high-range water-reducing admixtures? Question 3 (18 points) (I) A reinforcing bar has the following identification marks: K, 8, W, 75. What do they mean? (II) Approximately, how much would be the cost of formwork for building a concrete parking garage: 15%, 30%, or 45%? List the important factors that must be considered for formwork selection. (III) List the commonly used materials for making concrete forms, in ascending order of re-use. Question 4 (18 points) (I) Would you recommend a concrete mix to be volume-batched or weight-batched? Explain why. (II) Although calcium aluminate cement shows very high early strength and excellent resistance to chemical attack, yet it is not used much for structural purposes. Why? (III) Describe the advantages and disadvantages of using conveyors belt to transport concrete. Question 5 (14 points)A high-raise (50 stories) reinforced concrete building is being planned for a congested area in downtown Oakland. What type of equipment would you select for concrete placement? What changes in the concrete mixture may be necessary for a trouble-free placement? Question 6 (14 points) I) Define the term slump loss. What is the significance of slump loss in concrete construction practice, and how would you deal with the problem. II) What should be the spacing of the construction joints in a 6 ft slab? What about for a 12 ft slab? Assume for both cases a slab thickness of 6
View Full Document
Unlocking...