Concrete sludge and paper sludge (CSPS) brick
Abstract
Paper sludge is a waste from pulp and paper industry while concrete sludge is a waste
from construction industry, has caused environmental impact problem besides the
increasing of disposal cost. Focus this study, to producing a bricks by using waste from
pulp industry and construction industry. Nine brick mixes containing various contents of
waste (paper and concrete), sand brick and concrete sludge as control mix. The
percentage of mixing is 2%, 4%, 7%, 10%, 15%, 20%, 30% and 100% as replacement
by volume. Result of the test indicated that the sludge proportion was a key factor in
determining brick quality. X-ray Fluorescence (XRF) test, for concrete sludge and paper
sludge highly contain calcium oxide and silicon dioxide. For density, paper sludge
replacement from 2% to 100% is 1286 kg/m3 to 655 kg/m3 and compressive strength
from 1.60 MPa to 0.34 MPa. Range percentage water absorption for 24 hours is from
16.9% to 40.9%. Increase sludge content results in decrease of density, compressive
strength also decreases but water absorption increase.