Improving mechanical and durability properties of hypo sludge concrete with basalt fibres and SBR latex

Utilization, reduction and disposal of the pulp and paper industry waste (Hypo Sludge) are crucial from an environmental perspective. Hypo sludge, when disposed of as landfill, contributes to the groundwater contamination caused by the leachates. Hence, the utilization of hypo sludge from the paper industry in the construction applications promotes the development of sustainable concrete; reduces landfills, and creates an environment free from harmful wastes. In the present context, this research focused on the partial replacement of cement by hypo sludge. It was observed that even though the addition of 10% of hypo sludge was sufficient to produce sustainable concrete, there was a negative influence on the durability as more water absorption was observed due to the presence of high cellulose fibre content. Hence styrene-butadiene rubber (SBR) latex and basalt fibres were added to improve its durability and post cracking behaviour respectively. A significant improvement in the strength and durability was observed when 10% of hypo sludge as a cement replacement is used in combination with 0.25% of basalt fibres and 10% of SBR latex when compared with the conventional concrete. The micro structural studies revealed that SBR latex produced better consistency in the interaction among the phases of concrete.