Influence of using dry and wet wastewater sludge in concrete mix on its physical and mechanical properties

The recent researches are trying to explore the most suitable way for discarding the huge amount of sludge produced from wastewater treatment plants. One track of these solutions is to use sewage sludge in construction field such as "concrete mixtures and in manufacturing interlock brick samples". The objective of this paper is to study the influence of using dry and wet wastewater sludge in concrete mix on its physical and mechanical properties as a new way of discarding the produced sludge from the wastewater treatment plants. According to results findings, slight effect on the concrete mix strength was observed when using the dry or wet sludge with (5, 10 and 15%) of cement weight, however, using the sludge with 20% of cement weight decrease the strength by 61.6% for dry sludge and by 68.5% for wet sludge. The results showed that the wet sludge retarded the strength development and has more adverse effect on compressive strength than the other dry sludge for the same percentage, also the dry and wet sludge can be used in as an additive to concrete mixtures till 15% from cement weight as one of the available disposal options for sludge. (C) 2019 The Authors. Published by Elsevier B.V. on behalf of Faculty of Engineering, Ain Shams University.