The use of Dredged Marine Sediment in the Formulation of Air-foamed Concrete

A large quantity of sediments is dredged continuously worldwide. They are generally dumped in landfill areas which ensue in the increasing cost of the dredging operations and in soil-groundwater pollution. The objective of this work is to study the beneficial reuse of dredged sediments in foam mortar and particularly by studying the influence of the substitution of sand by dredged sediments. Air foam mortars/concrtes is an alternative to ordinary concrete, which presents the advantages of lightweight and low thermal conductivity. In this study, the density required ranges from 1200kg/m3 to 1600kg/m3 to the development of foam concrete building blocks and slabs for load-bearing and non-load-bearing structures. Twenty foam mortar mixes were prepared. Sediments were introduced by replacing 15%, 30%, and 50% mass of the sand. The foam percentage was introduced from 0–100% volume of mortar. Workability, compressive strength, and flexural strength at the age of 7, 28, and 60 days were monitored. The size distribution of foam bubbles and the effect of sediments on their stability is also studied. The results demonstrate that sediment has a good general effect on foam concrete and this opens up very promising new types of concretes. However, for a high substitution rate, a decrease in performances is denoted.