Cenospheres in Construction
The cenospheres are also used in the construction industry (cenospheres in construction) for the manufacture of ultra-light and aerated concrete.
The cementitious mixtures are used in combination with the microspheres additives as follows;
- Aggregate with a small mass. Cenospheres may substitute some amount of the sand in the concrete composition of a standard mass. The cenospheres density is almost 4 times lower than the density of quartz sand and the size of the largest cenospheres are the same size as the smallest granules of sand. The additional advantage of the cenospheres is that they are virtually “invisible” in the concrete, and therefore can be easily polished;
- Production aid. The use of cenospheres in the concrete mix with a standard weight improves the performance by allowing the particles to act as ball bearings. Since the microspheres are structural fillers, they increase the density of the concrete and its strength by providing a better compression. Typically 1.0-5.0 % of the weight of the mixture is added as cenospheres to improve the efficiency of the concrete mixture.
- Volumetric filler. The use of the cenospheres as the volume filler increases the volume of the mixture with no need for additional cement additives. Also the various sizes of fine particles contribute to the reduction of shrinkage.
The spherical shape of the cenospheres allows the particles to penetrate into very small openings, the areas that are normally inaccessible to the jagged edges of the sand particles. When utilizing the cenospheres as a volumetric filler, their mass reaches 10-30% of the mixture weight.
