Investigation of geopolymer mortar and concrete using manufactured sand and dredged marine sand under ambient curing conditions

Abstract

Finding alternate to cement concrete has become important for sustainable environment. Geopolymer concrete has proved itself to be a good substitute for conventional concrete due to reduced carbon foot prints. The source materials for making geopolymer concrete namely fly ash, GGBS, metakaolin, red mud etc are rich in silica and alumina. These source materials when combined with alkaline solutions yield geopolymer matrix. Fine aggregates and coarse aggregates along with superplasticers are also the chief constituents of making geopolymer concrete. The increasing demand of conventional materials lead to invention of alternate materials. On the other hand, several industrial products leave wastes such as fly ash, GGBS, red mud etc. which cause lot of issues while disposing. Also, similar issue is reported in marine environment. That is huge amount of dredging material needs to be disposed or large tracts of land are needed to be allocated for depositing the same. In this research work, an attempt is made to utilise fly ash, GGBS, Manufactured Sand (M-Sand) and Dredged Marine Sand (DMS) in producing geopolymer concrete. DMS from two different ports of Tamilnadu namely from Tuticorin and Chennai were utilised for the purpose. As new combination of fine aggregates(M-Sand and DMS) was tried in the present investigation, all necessary tests with regard to strength as well durability to find the suitability of these materials as per relevant standards were performed and reported. Geopolymer mortar cubes, geopolymer concrete cubes, cylinders, prisms and flexure specimens were cast for the purpose. Monotonic and cyclic loading behavior was performed with regard to flexural study. Further, microstructure characterisation was also made to determine the elemental composition as well the factors influencing the behaviour of new composition. Non destructive tests were also carried out to support the results of destructive tests. Corrosion monitoring was also done since DMS was used. Geopolymer concretehad proved itself to posse