Construction Engineering Assignment -
Q1. Which of the following factors does NOT directly influence the workability of fresh concrete?
1. Exposure classification
2. Aggregate shape
3. Level of hydration
4. Cement content
5. Water content
Q2. What particle shapes are considered desirable for aggregates used in a concrete mix?
1. Angular and elongated
2. Rounded, irregular and angular
3. Irregular and elongated
4. Rounded, flaky and elongated
Q3. Which of the following items is NOT one of the key components used in making Portland cement?
1. Fly ash
2. Calcium carbonate
3. Silica
4. Iron Oxide
5. Alumina
Q4. Which of the following items is included in the cement making process, to control the rate at which the cement hydrates when mixed with water?
1. Alumina
2. Gypsum
3. Limestone
4. Magnesium
Q5. Is the following statement true or false?
Generally, if water is drinkable, it is suitable for making concrete?
1. True
2. False
Q6. You are a local government Engineer responsible for the design and construction of a footpath and bikeway in the local parklands. Your design calculations indicate a requirement for 25 MPa reinforced concrete. Soil tests show the parklands contain non-aggressive soils, and you will not be using a membrane under the concrete. (Your footpath will not be submerged in water.)
Using the attached tables, calculate the Target Strength in MPa based on the minimum requirement for Characteristic Strength considering both strength and durability.
(Round your answer to one decimal place. Do not include the MPa unit or any spaces or commas.)
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Table 1: Minimum characteristic strength for durability
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Exposure classification
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Minimum characteristic strength fc' (MPa)
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A1
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20
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A2
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25
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B1
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32
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B2
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40
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C
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50
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Table 2: Assumed standard deviation
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Grade designation
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Characteristic strength MPa
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Assumed standard deviation MPa
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Standard grades
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25
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25
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4.8
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32
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32
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5.34
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40
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40
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5.9
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50
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50
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6.2
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Flexural grades
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F2.5
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2.0
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0.5
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F3.5
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2.5
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0.5
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Indirect-tensile grades
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IT2.0
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2.0
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0.5
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IT2.5
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2.5
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0.5
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Table 3: Exposure classification table (attached)
Q7. Your engineering ?rm has been awarded a contract to replace an existing timber bridge with a new concrete bridge over a river crossing in central Queensland. You will act as the onsite Project Engineer for the construction of the bridge piers. These piers will be submerged during the wet season and above water level during the dry season.
Using the attached tables, calculate the Target Strength in MPa based on the minimum requirement for Characteristic Strength for durability.
(Round your answer to one decimal place. Do not include any spaces or commas.)
Q8. A concrete retaining wall is being built as part of the construction of an underground car park below a new high-rise development. The Characteristic Strength is 40Mpa. Using the attached tables, calculate the water/cement ratio for use in the concrete mix design. (Note: Target strength should be used as the 28-day compressive strength)
(Round your answer to two decimal places. Do not include any spaces or commas.) Table 1: Assumed standard deviation
Q9. The reinforced concrete base slab for a single storey residential house is to be constructed. The characteristic strength is 25MPa. Using the attached tables, calculate the water/cement ratio to be used to design the concrete mix.
(Note: Target strength should be used as the 28-day compressive strength) (Round you answer to two decimal places. Do not include any spaces of commas.)
Q10. Using the following known information, what is the aggregate/cement ratio to be used in the concrete mix design based on a water/cement ratio of 0.6?
Nominal aggregate size: 40 mm
Aggregate shape: irregular gravel
Slump: 160 mm
Grading curve: 3
(Round your answer to one decimal place. Do not include any spaces or commas.)
Q11. Using the following known information, what is the aggregate/cement ratio to be used in the concrete mix design based on a water/cement ratio of 0.7:1?
Nominal aggregate size: 20 mm
Aggregate shape: crushed rock
Slump: 40 mm
Grading curve: 4
(Round your answer to one decimal place. Do not include any spaces or commas.)
Q12. A concrete design has been completed for an upcoming project, with the following parameters:
- Water/cement ratio is 0.60
- Aggregate/cement ratio is 3.6
The total aggregate proportions in the blend are as follows:
- 20 mm aggregate 20%
- 10 mm aggregate 65%
- Sand 15%
Calculate the total mass of concrete mix (in kg) using these proportions, based on a 50 kg bag of cement.
(Round your answer to one decimal place. Do not include the kg unit or any spaces or commas.)
Q13. You have an approved mix design for a concrete pour that will be taking place tomorrow morning. You are in an arid zone of Queensland and have not had any rainfall for over 2 months. Your 20 mm aggregate has been in stockpile for a number of weeks and is now very dry. Your mix design quantities for a 1 m3 batch of concrete, based on the Saturated Surface Dry condition of the aggregate are as follows:
Cement 428 kg
Water 201.2 kg
20 mm aggregate 1061.4 kg
Sand 650.6 kg
Total 2341.2 kg
The soil laboratory have taken samples from the aggregate stockpiles, and found that the actual moisture content of the 20 mm aggregate is 1.8 %, and the water absorption is 2.1 %. The sand is in SSD condition.
What is the total quantity of water in kg to be included in the concrete mix, after the adjustment for aggregate moisture content?
(Round your answer to one decimal place. Do not include the kg unit or any spaces or commas.)
Attachment:- Assignment File.rar