Stone and Aggregate

1、单选题：
‌Geologists classify rocks into three basic types: Which one of the below is not the three basic rock types?​
选项：
A: Sedimentary Rock
B: Igneous Rock
C: Limestone Rock
D: Metamorphic Rock
答案: 【 Limestone Rock】

2、单选题：
​What type of rock is formed when heat and pressure change the composition?‍
选项：
A: Residual
B: Igneous
C: Sedimentary
D: Metamorphic
答案: 【 Metamorphic】

3、单选题：
‍What is the demarcation between coarse aggregate and fine aggregate for asphalt material?‌
选项：
A: 2.36 mm
B: 4.75 mm
C: 0.075 mm
D: 25.4 mm
答案: 【 2.36 mm】

4、单选题：
‏An aggregate sample has a total density of 1,740 kg/m3 and water content of 15%.  The specific gravity of the aggregate is 2.65. What is the dry density of the sample?​
选项：
A: 2,052 kg/m3
B: 1,650 g/m3
C: 1,513 kg/m3
D: 1,432 kg/m3
答案: 【 1,513 kg/m3】

5、单选题：
‌A well-graded aggregate contains:‎
选项：
A: Mostly particles passing the 4.75mm sieve
B: Particle sizes which are primarily within a small band
C: A range of particles sizes that are missing.
D: Particles of all sizes in good distribution
答案: 【 Particles of all sizes in good distribution】

6、单选题：
‌An aggregate sample has a moisture content of 8%. How much water must be added to increase the moisture content to 12%? You originally started with 2400 g of aggregate with air-dry moisture content of 3.5%​
选项：
A: 81g
B: 91g
C: 94g
D: 86g
答案: 【 91g】

7、单选题：
‎For an aggregate sample, the percent passing 24.5mm, 9.5mm, 4.75mm, and 2.36 sieves are 100%, 98%, 80%, and 60%, respectively. What is the nominal maximum aggregate size of the sample?‎
选项：
A: 2.36mm
B: 4.75mm
C: 9.5mm
D: 24.5mm
答案: 【 4.75mm】

8、单选题：
​An aggregate’s voids are filled with moisture but the main surface area of the aggregate particles is dry. Which of the following moisture condition does it belong to?‌
选项：
A: Bone dry
B: Air dry
C: Saturated surface–dry (SSD)
D: Moist
答案: 【 Saturated surface–dry (SSD)】

9、单选题：
‍The surface chemistry of aggregate can be divided by the content of SiO2. The basic aggregate has SiO2‏
选项：
A: SiO2 ≥ 65%
B: SiO2 ≤52%
C: SiO2 = 52~65%
D: SiO2 = 0%
答案: 【 SiO2 ≤52%】

Portland Cement

1、单选题：
​The typical ingredient that easily leads to corrosion of hydrated cement is‎
选项：
A: 3CaO.SiO.nH2O
B: Ca(OH)2
C: 2CaO.SiO.nH2O
D: 3CaO.Al2O3.3CaSO4.32H2O
答案: 【 Ca(OH)2】

2、单选题：
‎Compared with ordinary Portland cement, which choice in the following is right as to the composition of Portland cement for road?‏
选项：
A: It has more C3A and less C4AF
B: It has more C3S and less C3A
C: It has less C3A and more C3S
D: It has less C3A and more C4AF
答案: 【 It has less C3A and more C4AF】

3、单选题：
‍When the slump of fresh concrete does not meet the requirement, the right way to improve workability is‍
选项：
A: Increasing cement paste under same W/C condition
B: Decreasing cement paste under same W/C condition
C: Adjusting cement paste under same W/C condition
D: Increasing or decreasing water quantity
答案: 【 Adjusting cement paste under same W/C condition】

4、单选题：
‍After some water reducing agent is used into concrete, the function of the agent is  ( ) if some water is reduced‏
选项：
A: to improve concrete mechanics
B: to reduce concrete cost
C: to change concrete workability
D: to increase concrete flowability
答案: 【 to change concrete workability】

5、单选题：
‎Ordinary Portland cement is not suitable for( )‌
选项：
A: cold region
B: wet environment
C: mass concrete
D: high loading condition
答案: 【 mass concrete】

6、单选题：
‏Maximum W/C and minimum cement requirement will affect ( )‎
选项：
A:  concrete strength
B: concrete workability
C: concrete durabili