LECA is a special type of light aggregates that has been pelletized and fired in a rotary kiln at a very high temperature. As it is fired, the organic compounds are burn off forcing the pellets to expand and become honeycombed while the outside surface of each granule melts and is sintered. The resulting ceramic pellets are lightweight, porous and have a high crushing resistance
PROPERTIES OF LECA:
Lightness of LECA is for the multi-separated air spaces which exist inside and among the aggregates, density of aggregates, depending on the size of Leca (i.e 0-25 mm ), ranges from 400 to 800 kg/m3
Leca aggregate works as an best sound /acoustics
Thermal conductivity coefficient :
Leca aggregate is about 0.07 to 0.10 w/mk , and for,
Leca concrete it ranges from 0.12 to 0.15 w/mk.
LECA aggregate strongly resists against alkaline and acidic substances and pH value, makes it neutral in chemical post reaction with concrete
For closed inside porousness, average water absorption of Leca aggregate (0-25 mm) is about 40% percent of volume in saturated state during 48 hours.
Applications and Advantages:
Four usual sizes are 0-4mm, 4-10mm, 10-25mm , and 0-25mm. Leca bulk dried density and their applications for different gradations are illustrated in table, below:
0-4 mm 800 kg/m3
4-10 mm 600 kg/m3
10-25 mm 380 kg/m3
0-25 mm 450 kg/m3
Since LECA aggregates are exposed to higher temperature in rotary kiln, these aggregates enhances good fire resistance
LECA IN CONSTRUCTION:
Lightweight aggregates concrete:
In all the cases which lightening and insulation should be considered in buildings, Leca light weight aggregate ,(structural& non- structural) comparing to autoclaved aerated concrete foam concrete or concrete made of pumice or scoria has a wider range of applicability.
LECA lightweight concrete block:
LECA back is produced by mixing of Leca aggregates, Cement, sand and water. Using of Leca aggregate decreases the concrete density.
Lightening up to 30% of dead load
Self thermal & Sound Insulation
Appropriate Behavior in Earthquake
Low Module of elasticity of Leca Concrete, and having , cement base material as well as its mortar, in addition to the lightness, reduces the destructive effects of earthquake on structure. Shapes of Leca blocks are designed for conducting vertical mortar in joints which minimizes the rubble threat. Referring to mentioned reasons, using of Leca blocks prevents buildings from asymmetric settlement and other detrimental side effects.
LECA Blocks are suitable for any physical operation like cutting, nailing, transfixing and ridge extending to make proper route for wire, pipe and other installing components without any cracking.
Accelerating Construction, Saving time, Labor, and material
For lightness and different sizes and dimensions of Leca blocks, walling up could be done in high speed which ,leads to save time, labor and material.
Safe for Installation
Being chemically neutral, Leca aggregate and blocks , are the best bed for buiding installation and prevent pipe and wires from decay. Leca blocks are designed in a way not to be only lightweight but cover all required.
FLOORING AND ROOFING:
Lightness, insulating, durability, non-decomposability,structural stability, and chemical neutrality features are collected in Leca as the best lightweight aggregate for flooring and roofing and in the most suitable and reasonable replacement for pumice, scoria and polystyrene, moreover Leca aggregates are used to mark insulating lightweight concrete for all floors substructures under stone, marble or ceramic etc.,Wasting energy is 35% through the roofs while it is 15% for the walls.
LECA AGGREGATE IN AGRICULTURE:
Leca prepares the best convenience bed for growth of Plants due to:Ventilating of the soil and root, preventing soil from evaporation and saving water for sponge like body of aggregate, water feeding adjustment, lightness insulation, chemically neutral, environmental-friendly, cleaner than soil and no pestilential effects on soil,plants or your hands.