Final answer:
The largest difference in a lightweight concrete mixture is the use of light materials like shale, clay, or slate as coarse aggregate, making the concrete lighter, which in turn allows for faster construction, longer durability, and better insulation.
Step-by-step explanation:
The largest difference in a light weight concrete mixture compared to traditional concrete is the type of aggregates used in the mixture. In lightweight concrete, the coarse aggregate consists of materials like shale, clay, or slate, which are significantly lighter than the gravel and small pebbles used in standard concrete mixes. This reduction in weight provides numerous advantages, such as decreasing the overall load of the structure, allowing for faster building rates, improving the longevity of the construction, and offering superior thermal insulation compared to brick.
The lightweight concrete has seen advancements in the last century especially, becoming more reliable and predictable, with the ultimate compressive strength reaching 20 × 106 N/m², and despite the ultimate shear strength being lower, this form of concrete is less likely to break under normal conditions. Moreover, pumping concrete through hoses, as opposed to using wheelbarrows, has improved efficiency in construction practices and has been tailored to accommodate the specific properties of lightweight concrete, such as using a mixture with the right viscosity and density for a laminar flow.