What are the approximate average densities for NWT, SLWT, and LWT concrete?

The average densities for Normal Weight Concrete (NWT), Structural Lightweight Concrete (SLWT), and Lightweight Concrete (LWT) can vary based on the specific materials used and the proportions in the concrete mix, but the range presented in the selected answer generally aligns well with industry standards.

Normal Weight Concrete typically has an approximate density of around 145 lb/ft³, which is consistent with the average used in most structural applications due to the density of aggregates typically utilized. Structural Lightweight Concrete is designed to have a lower weight and thus typically falls around 125 lb/ft³. Finally, Lightweight Concrete, which can often use expanded clay or similar materials, results in an approximate density of 110 lb/ft³. These values allow for efficient calculations in design and application of various concrete types depending on the structural requirements.

The other options do not align closely with the industry norms for these types of concrete densities, making them less accurate in reflecting what is commonly used in practice. Therefore, the density ranges provided in the selected answer are in accordance with standard construction practices and materials science, aiding in the successful application and understanding of these concrete types in various construction scenarios.