Microstructure and performance of sludge-ceramisite concrete

A research program was carried out to investigate the microstructure and performance of light-aggregate concrete prepared with ceramisite sintered from sewage sludge. The results showed that the ceramist is mainly composed of cristobalite and mullet, and has dense enamel structure on its surface and honeycomb close fine porous structure. It was also found that the use of large particle size of ceramisite will decrease the compressive strength, stability and workability of the ceramisite concrete. Furthermore, the appropriate addition of mineral admixtures could improve the compressive strength and workability of the ceramisite concrete, while the compressive strength increases with the decrease of water–cement ratio and the increase of sand ratio to some extent.

► Ceramisite can have enamel surface, uniformly distributed fine porous structure.
► Light weight and high strength is attributed to formation of cristobalite and mullite.
► There are appropriate dosages of mineral admixtures in ceramisite concrete.
► Lower water-to-cement ratio leads to high compressive strength of ceramisite concrete.