Fly Ash as Supplementary Cementious Material in Portland Pozzolana Cement Concrete

Fly ash is a byproduct obtained from industries where coal or lignite is burnt like thermal power plant, steel, sugar, fertilizer industries etc. The Fly Ash is a class of artificial pozzolans, and generally comes in the category of non-conventional building material. It is particularly designed and processed as part supplement of cement in concrete to achieve improved performance.This work describes the utilization of this supplementary material (Fly ash) which is easily available, in the growth of new materials and technologies. It is considered that this material can be used as a supplementary material as partial replacement of cement in the construction industry in different areas. In the present study PPC cement was replaced by fly ash accordingly in the range of 0 to 60 % by weight of PPC cement at water cement ratio 0.48 for M-25 mix. Concrete mixtures were produced, tested and compared in terms of compressive strength. 1

Microstructural Evolution of a Transformation in Which There Is an Exclusion Zone Around Each Nucleus

Depending on the physical circumstances, two nuclei might not form very close to one another. That is, there might be an exclusion zone around each nucleus. Formal treatments of nucleation and growth transformations normally suppose that nuclei are located uniform randomly, i.e. according to a Poisson point process, within the matrix. In this work, we model nuclei location in space using the so-called Sequential point process. The Sequential point process can produce a range of nuclei arrangements in space in which each nucleus possesses an exclusion radius. Computer simulations of transformations with these nuclei arrangements are compared with a transformation nucleated according to the usual Poisson point process. The resulting microstructural evolution is characterized by usual stereological parameters as well as by the two-point correlation function. The results show that the effect of the exclusion zone relative to the usual uniform randomly nucleation can be significant