抄録
Many researches already concluded that concrete which contains fly ash usually possesses higher rates of pozzolanic reactions with increasing pore sizes of 0.1μm or less. When a pozzolanic reaction evolves, densification of CSH hydrates also starts. This densification process is high in 0.003–0.01μm size of pore and low in 0.01–0.05μm size of pore. The technology described in this paper is related to the microstructure change in granulated foundation materials, which contain primarily fly ash mixed with small amounts of cement. The authors developed a special mixer that can be used to prepare granular foundation materials from mixing of water, fly ash, and cement. This kind of foundation material has many similarities with natural foundation materials like sand and crushed stone, and it can be produced by a single process of mixing in a short time.
Similar to the fly ash concrete, the granulated foundation material chiefly composed of fly ash and a small amount of cement contains many pores of sizes 0.1μm or less. Experiments also concluded that when hydrated lime was added into the granulated foundation material to prevent leaching of heavy metals and other substances, CSH hydrates developed in pores of size 0.1μm or less and the material consisted of approximately 50% of the total pore space.
The authors also used an electron probe microscope analysis (EPMA) and measured pore size distribution after addition of hydrated lime to the granulated foundation material. It made easier to understand the changes in micro-structure and to explore the causes behind the development of different microstructures in the granulated foundation material after addition of hydrated lime.
