Final answer:
Labor costs typically account for at least half of the total cost of site poured concrete due to the intensive process of framework construction and concrete work. Lightweight concrete, made of lightweight aggregates, offers advantages that include faster construction and better thermal insulation.
Step-by-step explanation:
In most cases, labor costs account for at least half of the total cost of site poured concrete. When constructing with concrete, a wooden framework, or formwork, is built to shape the space where the concrete is to be poured. This labor-intensive process, along with other aspects of concrete work such as mixing, pouring, and finishing, contributes to the high cost of labor relative to materials.
The use of lightweight concrete, which is a mixture of lightweight coarse aggregate with fine aggregates like shale, clay, or slate, offers multiple advantages over traditional heavier concrete. Not only does it reduce the overall load, leading to faster building rates, but it also lasts longer and serves as an excellent thermal protector, notably when compared to brick. This innovation in concrete technology contributes to the construction process, potentially affecting labor and overall costs.