Structural lightweight concrete is a type of concrete made with low density aggregates, usually with a density of 1,440 to 1,840 kg/m3, compared to normal weight concrete which has a density of approximately 2,240 to 1,840 kg/m3. 2400kg/m3. Compressive strength over 28 days should be greater than 17 MPa. These values ​​are obtained using lightweight coarse aggregates and normal weight fine aggregates, typically including pyrotreated shales, clays, slates, expanded slag and expanded fly ash. (NRMCA, 2003) The main use and advantage of lightweight structural concrete is to reduce the weight of a concrete structure, thereby reducing the size of structural elements and the volume of concrete, as well as reducing the quantity of concrete. of reinforcing steel required. The higher strength-to-weight ratio resulting from these factors compensates for the fact that lightweight concrete is slightly more expensive, while still producing a more economical product. (NRMCA, 2003)Lightweight concrete plays a major role in the construction of large-scale structures around the world, typically bridges and high-rise buildings. With the industry and products constantly improving, lightweight concrete will continue to have a huge impact in the future. History The use of lightweight concrete can be traced back to before the days of the Roman Empire, although very simple and overall quite weak materials, they were very durable, and some extant examples can still be found in early structures of the Mediterranean era. (Exped Shale Clay and Slate Institute, 2010) The Roman Empire later implemented the use of lightweight concrete wherever the local supply of materials permitted, as their rapid expansion led to the need for many more materials solids...... middle of paper ......not only is weight an important aspect of concrete, but fire resistance is an essential element of any building and therefore of concrete. The fire resistance qualities of LWC are superior to those of normal concrete due to its significantly lower thermal transmission. LWC can also be considered very durable and highly resistant to moisture, even after daily wetting cycles spanning 30 years. Moisture resistance helps prevent steel and other reinforcing components from resisting the natural corrosion of salt water. The benefits of this concrete are not only for workers but also help architects and engineers to open up a wider range of applications. Examples of new advancements due to LWC include: high-rise building frames, long-span roofs and bridge structures and thin-shell constructions (hyperbolic parabolic roof structure, sculpture and special design effects).