6.2.2. Effect on Strength

Try these first

1. 1.

   What happens when chlorides are present in water used for concrete?

   Hint

   Think about how chlorides interact with steel.

2. 2.

   What are sulphates known to do in concrete?

   Hint

   Consider their effect on the cement's reaction.

3. 3.

   What type of impurities can severely affect the strength of concrete?

   • Chlorides
   • Sulfates
   • Both A and B

   Hint

   Consider the impact of both on hydration.

4. 4.

   True or False: Chlorides can cause premature hardening of concrete.

   • True
   • False

   Hint

   Reflect on what premature hardening means.

5. 5.

   A construction engineer is tasked to use concrete in a heavy traffic area. The local water source has high chloride content. What steps could the engineer take to ensure the concrete's strength?

   Hint

   Think about ways to enhance water quality.

6. 6.

   Two concrete samples were made, one with clean water and one with water containing high levels of sulphates. After curing, the sulphate-treated sample cracked significantly more. What are the implications for engineers?

   Hint

   Reflect on testing protocols for water quality.