Study of Strength and Durability Characteristics of Concrete Mixes Made by Unwashed Sea Sand as Fine Aggregates

The use of sea sand in concrete can reduce burden on river sand, which can help in protecting the environment. Although testing of concrete mixes using sea sand, sea water, or both has been reported in the existing literature, studies based on the use of unwashed sea sand are limited. Further, it has been reported in the literature that the concrete properties are influenced by the origin of sea sand. This paper presents experimental studies to investigate suitability of unwashed sea sand as fine aggregates in structural concrete. The properties of concrete mixes made by four levels of sea sand addition were investigated from the perspective of strength and durability in this paper. These levels of river sand replacement include 30 % (designated as 30SS), 50 % (designated as 50SS), 70 % (designated as 70SS), and 100 % (designated as 100SS). Mixes made with river sand were used as control mixes (designated as 0SS). All the employed mixes provided the required compressive strength at 28 days. Similar permeability characteristics were observed for the 0SS and 30SS mixes. Chloride ion penetration of the 70SS and 100SS mixes increased with time, whereas it reduced for the other mixes. Water absorption and permeability of these aforementioned mixes were also higher compared to the other mixes. The corrosion and aggregate-silica reaction potential were not indicated by the testing of the employed mixes after 1 year.