Florida DOT Concrete Batchman/Operator Practice Exam

What is the primary purpose of using an accelerator in concrete?

1. To improve strength

2. To reduce curing time

3. To enhance flowability

4. To adjust color

The correct answer is: To reduce curing time

The primary purpose of using an accelerator in concrete is to reduce curing time. Accelerators are chemical admixtures that speed up the hydration process of cement, allowing concrete to set and gain strength more quickly than it would under normal conditions. This is particularly beneficial in cold weather or when there are time constraints on construction projects. By reducing the time it takes for the concrete to cure, it allows for faster project completion and the ability to move on to subsequent construction phases without delay. While it is true that using an accelerator can lead to an initial increase in strength in the short term, the main function is not to enhance the overall strength of the concrete but to expedite the setting and curing process. Other choices, like enhancing flowability and adjusting color, are not primary functions of accelerators; those purposes are generally achieved through different admixtures designed explicitly for those characteristics.