ACI Concrete Field Testing Technician - Grade I Practice Exam

What is considered an acceptable slump result for concrete testing?

1. A slump greater than 2 inches

2. A uniform slump across all tests

3. Consistency in results over multiple tests

4. A slump of 1-4 inches, depending on the mix

The correct answer is: A slump of 1-4 inches, depending on the mix

An acceptable slump result for concrete testing is primarily defined by the requirements of the specific concrete mix being used, with a common standard being a slump of 1-4 inches. This range allows for adequate workability for most concrete applications, ensuring that the concrete can be properly placed and compacted without excessive water content that can affect strength and durability. For different types of mixes, particularly those designed for specific structural or aesthetic purposes, the acceptable slump may vary. For instance, structural concrete may typically fall within the lower end of the range to maintain strength, while mixes for decorative pours could allow for higher slumps. Ultimately, achieving a slump within this specified range helps ensure that the concrete can be worked efficiently on-site while also meeting the design and performance criteria. Consistency in results, while important for confirming quality control during mixing and field application, does not define the acceptable slump itself. Similarly, having a uniform slump across all tests is valuable, but it does not guarantee that the slump meets the required specifications for that particular mix.