Final answer:
To increase the strength and reduce the weight of a post-tensioned slab, steel tendons are added, and lightweight concrete is used. These techniques enhance load-bearing capacity while providing excellent thermal protection.
Step-by-step explanation:
In a post-tensioned slab, steel tendons are added to provide extra strength and reduce weight. This is a practice in modern construction that allows concrete to withstand greater tensile and compressive forces. By tensioning these steel tendons after the concrete has cured, compressive forces are introduced, which makes the slab more capable of bearing loads and deflects less, allowing for longer spans and thinner slabs.
Lightweight concrete, which incorporates lightweight aggregates like shale, clay, or slate, is also often used in conjunction with steel tendons to reduce the overall weight of the structure without compromising its load-bearing capacity and structural integrity. This results in constructions that are faster to build and longer-lasting. The ability of lightweight concrete to provide excellent thermal protection compared to heavier materials like brick is an additional benefit, aiding in the thermal efficiency of buildings.