It is a type of concrete which whole or some part of ordinary aggregate replacing with an artificial lightweight aggregate.
Structural or semi-structural Light Weight Concrete (LWC) has been used in usual civil engineering applications as a very convenient alternative to conventional concrete. Structural lightweight concrete made with rotary kiln produced structural lightweight aggregate solves weight and durability problems in buildings and exposed structures. Structural lightweight concrete has strengths comparable to normal weight concrete, yet is typically 25% to 35% lighter. Structural lightweight concrete offers design flexibility and substantial cost savings by providing less dead load, improved seismic structural response, longer spans, better fire ratings, thinner sections, decreased story height, smaller size structural members, less reinforcing steel, and lower foundations costs, also LWC can easily pumping to higher floors. Structural lightweight concrete precast elements have reduced trucking and placement costs.
Concrete using ESCS lightweight aggregate has better thermal properties, higher fire ratings, reduced autogenously shrinkage, excellent freezing and thawing durability, improved contact zone between aggregate and cement matrix, less micro-cracking asa result of better elastic compatibility, more blast resistant, and has better shock and sound absorption, High-Performance lightweight aggregate concrete also has less cracking, improved skid resistance and is readily placed by the concrete pumping method. LECA mortar can be used like normal mortar for built of block wall or all masonry products with all advantage of LECA, for example one of the best usages of LECA grout or mortar is to protect steel structural elements for fire and corrosion attacking.
LECA aggregate are produced according the ASTM C-330 & C-331 and LECA concrete shall meet guide line of ASTM 211.2 & 318.
The mostly of uses lightweight concrete are as following subjects:
- LECA concrete can be used in different type of slabs in RC frame or deck of steel frame structures, beams or columns as RC elements or as fire protection of steel members
- Post tension slab or beam system, Bridge decks, piers & AASHTO griders
- Specified density concrete, it can be ordered as structural engineer requirement with different density and obviously different compressing strength fc which mix design could be prepared accordingly.
- Lightweight concrete precast & prestressed elements (beams, double-tees, tilt-up walls, raised access floor panel planks, hog slats, utility vaults, pipes, ornamentals, etc.)
- LECA concrete or grout can create packages of lightweight, safe and insulating roof and also it allows for creation of slopes for the drainage of rain water and of ballasting of waterproof surfaces.
- Marine structures, floating docks, ships, & offshore oil
- Asphalt pavements (rural, city & freeway)
- Lightweight asphalt bituminous surface treatments, lightweight chip seal, seal coat, etc