Near-Surface and Chloride Permeability of Concrete Using Pozzolanic Materials and Manufactured Sand as Partial Replacement of Fine Aggregate

The overuse level of cement and natural sand for civil industry has several undesirable social and ecological consequences. As an answer for this, industrial wastes called by-products (pozzolanic materials) like fly ash, GGBFS, silica fume and metakaolin can be used to interchange partially cement and natural fine aggregate by manufacturing sand (M-sand). Thus, the present research work reported in this article deals with the feasibility study of using manufactured sand as sand replacement and pozzolana as cement replacement materials in concrete. So this will solve two problems simultaneously, viz. the bulk utilization of pozzolanic materials and saving the natural quarries of sand. Thus, the research work presented here specifically dealt with the potential utility of manufactured sand as sand replacement and pozzolana as cement replacement material and its effect on the durability and microstructure properties. Thus, the main objective of this experimental investigation is to find out the durability properties of concrete produced by replacing natural sand by manufactured sand in varying percentages like 0%, 10%, 20%, 30%, 40%, 50%, 60% 70%, 80%, 90% and 100%, and 20% cement replacing with pozzolanic materials. In this experimentation, natural fine aggregate was partially replaced by M-sand in various percentages 0-100% with 10% interval, water-cement ratio of 0.45, and cement was partially substituted by 20% of pozzolanic materials. M30 concrete grade proportions were considered as per IS 10262:2009 guidelines. The durability properties like water absorption, sorptivity and chloride permeability results were checked for the different concrete mix proportions and compared with conventional concrete. From this research work, it can be concluded that for replacement of 60% natural fine aggregate by manufactured sand (M-sand) and 20% cement by silica fume yields minimum water absorption, sorptivity, chloride permeability and denser microstructure than conventional concrete.

Automated summary

This research investigates the feasibility of using manufactured sand and pozzolanic materials to replace natural sand and cement in concrete, showing that replacing 60% natural fine aggregate with M-sand and 20% cement with silica fume results in concrete with superior properties.