Florida DOT Concrete Batchman/Operator Practice Exam

Which Portland Cement type is suggested for mass placements?

1. Type I

2. Type II

3. Type III

4. Type IP

The correct answer is: Type II

The selection of Portland Cement type for mass placements is crucial for ensuring structural integrity and performance. Type II Portland Cement is specifically formulated to provide moderate resistance to sulfate attack and to limit heat generation during the hydration process. This characteristic is particularly important in mass placements, where large volumes of concrete can generate significant heat as it cures. The heat could lead to thermal cracking if not adequately managed. In scenarios involving mass concrete such as foundations, large structural elements, or pavements, the risk of cracking due to temperature differentials is a primary concern. Type II cement's ability to mitigate these risks makes it an ideal choice, allowing for a balance between strength development and temperature control within the concrete mass. Other types of Portland Cement, such as Type I, Type III, and Type IP, serve specific purposes not aligned with the needs of mass placements. Type I is a general-purpose cement, while Type III gains strength more quickly but can generate more heat, which is less favorable for mass placements. Type IP blends with pozzolan, which may not provide the same thermal benefits. Therefore, Type II is the recommended choice due to its performance characteristics suited for preventing issues in mass concrete applications.