Green approach on ternary blended pre stressed cement concrete railway sleepers

Abstract

Conventional Railway concrete sleepers are manufactured using steel pre-stressed strands upto pre-determined stress level surrounded by well compacted controlled concrete. The concrete used in manufacturing of railway sleepers is made up of 53 grade ordinary Portland cement with natural aggregates. Though, experiments have been conducted worldwide with various unorthodoxical constituent materials, the standardization of such non-conventional materials used for concrete sleeper manufacturing on Indian Railways (IR) is yet to be established. The pretensioned prestressed concrete (PSC) sleepers for Broad Gauge (BG) should pass the specified acceptance criteria T 39-85 of 2011 as per the Indian Railway Standard specification issued by Research Design Standard Organisation (RDSO).Abundantly available industrial wastes, such as Fly ash and other supplementary cementitious materials viz., ground granulated blast furnace slag (GGBFS), metakaoline (MK), silica fume (SF) have been found, through experimental investigations which improves some of the characteristic strengths of concrete. Utilising these materials in railway sleepers manufacturing process contributes carbon foot print (CFP) mitigation on one hand, the growing concerns of waste disposal and management are also addressed concurrently. The findings of current experimental studies indicate, the PSC sleeper manufactured with ternary blended concrete (TBC) of different percentage level of replacement of cement along with partial replacement of natural coarse aggregate, exhibit good strength characteristics. These sleeper specimens qualify the specified standard bending test (SBT) for sleepers namely moment of resistance (MR), whereas failing moment of failure (MF) at failure loads at rail seats criteria only.The experimental findings hold promise to conduct further studies with lesser percentage levels of sintered fly ash coarse aggregate i.e., standalone 40% in the current study. From application stand point, the manufactured TBC- PSC can be used in loop lines, berthing tracks and non-passenger freight-oriented lines, major shunting yards.