Use of Over-Burnt Bricks as Coarse aggregate in Concrete

Abstract

In modern construction industry number of materials are used and one of the materials is Brick. Regular
bricks are generally used in buildings or in some other engineering applications. In manufacturing of these bricks, a lot
of waste is produced in the form of over- burnt-bricks. The bricks being near to the fire in the furnace receives a
temperature more heat and eventually shrink and loose its shape, its color becomes reddish. These bricks can’t be used
in construction, directly because of their distorted shape dark color. hose over-burnt brick could be a source of recycled
coarse aggregate. The primary goal of this paper is to assess the suitability of incorporating over-burnt bricks in
concrete, by the partial replacement of natural coarse aggregate (NCA) with overburnt brick aggregate (OBBA) in a
ratio of 20%, 50%, and 100%. Initially, mix proportion of 1:2:4 and w/c of 0.57 was selected. By replacing NCA with
OBBA while using mix proportion of 1:2:4 and w/c of 0.57, the resulting concrete was found non-mixable and nonworkable. Thus, mix was designed (for targeted strength of 4ksi) for all replacement percentages. Slump test was
conducted for each replacement and the results show that by increasing replacement percentage the workability of
concrete decreases. the slump values are in between the range of 3–1.5 inches. For compressive strength the cylindrical
specimens of 6" x 12" were tested at 3, 7, and 28 days. For 20% replacement, the loss in compressive strength is 42.16%
for 3 days and for 7 and 28 days the loss is 46.96% and 61.37% respectively. For 50 % replacement, the loss in strength
for 3, 7 and 28 days is 29.73%, 30.87% and 58.29% respectively. For 100% replacement, the loss in strength for 3, 7 and
28 days is 48.65%, 55.65% and 69.19%