Lec 5 mcqs hard

What is the main effect of mid-range water-reducing admixtures?

Which ASTM standard or AASHTO specification is associated with high-range water-reducing admixtures?

What is the primary purpose of plasticizers for flowing concrete, also known as super-plasticizers?

What is the Steric inhibition of particle-particle contact associated with in superplasticizers?

Which phenomenon is associated with the dispersion of cement particles without any addition?

What happens when the cement content needs to be increased to maintain equal f'c for lean mixtures with a lower f'c and higher w/c ratio?

How do water reducer admixtures affect the workability of concrete?

What type of admixture is used to reduce water permeability under pressure in concrete?

Which admixture type controls the corrosion of steel reinforcement in concrete?

How do accelerators affect the compressive strength of concrete?

What effect does a higher temperature of concrete have on air content?

How does the proportion of fine aggregate in the total aggregate affect air generation?

What is the impact of vibration on air content in concrete?

How does the slump of concrete affect air content?

What is the relationship between water-cement ratio reduction and compressive strength in rich mixtures with air entrainment?

What effect do bubbles approaching each other have?

In the context of concrete exposed to sulfate soil, what is stated as the most important parameter?

What is the spacing factor defined as in relation to the air-void system?

What does a spacing factor of less than 0.2 mm (0.008 in.) indicate according to ASTM 457?

How can the spacing of air bubbles be measured according to the text?

Which of the following is NOT a main compound used in the manufacture of water reducers?

What is the main objective of water reducer admixtures?

Which compound is often suggested as an alternative to CaCl2 as a non-chloride accelerator?

What effect does the addition of CaCl2 have on freeze/thaw damage and alkali aggregate expansion in concrete?

What is the typical range of compressive strength for Ultra-High Performance Concrete (UHPC)?

What is the main purpose of water-reducing admixtures in concrete?

Which type of admixture is commonly used in cold weather construction to speed up the building process?

What is the primary function of retarding admixtures in concrete?

How do accelerators affect the hydration rate and strength of concrete?

Which type of admixture is designed to decrease water content in a concrete mix while maintaining workability?

What is the typical content of reducing sugars in waste liquor used in paper making?

Which compound tends to entrain air in concrete among the options provided?

When were water reducers developed as per the text?

What is the primary function of lignosulfonates and hydrocarboxylic acid in concrete?

Which admixture leads to better particle packing and higher degree of hydration at later ages?

What effect do most water reducers have on bleeding rate and capacity in concrete?

How do retarding admixtures affect the early strength of hardened concrete?