| The purpose of this study is to utilize waste products: Precipitated Calcium Carbonate
(PCC) and Upcycled Recycled Concrete Aggregate (UCA) in civil engineering. PCC is a fine to
coarse grain waste product generated during sugar production from sugar beets. UCA is
produced from demolished and returned concrete by primarily extracting calcium and alkalinity.
The test results on PCC alone show that the optimum content to achieve a minimum 4000 psi (28
MPa) compressive strength is 25% and 30%. The corresponding compressive strength of mixes
in which conventional aggregate was replaced by UCA is about 7000 psi (48 MPa) to 8000 psi
(55 MPa) at the same water-to-cement ratio (0.44) by weight. The compressive strength of
concrete with 25% to 30% cement replaced by PCC and varying amounts of aggregates replaced
by UCA ranges from 2800 psi (19 MPa) to 5800 psi (40 MPa). Other tests on PCC and UCA
include split tensile strength: 293 psi (2 MPa) to 423 psi (3 MPa) and flexural strength: 183 psi
(1 MPa) to 279 psi (2 MPa). Furthermore, the inclusion of PCC improved the resistance of loess
to saturation collapse. A significant average increase of 10% to 28% in the strength of loess
samples stabilized was found with 5% PCC compared to the strength of the native soil. Chemical
compositions on PCC were analyzed through X-ray diffraction (XRD) and energy-dispersive Xray spectroscopy (EDX). Based on the test results, the composition of PCC by weight indicates
45.9% calcium, 39.4% oxygen, and 9.2% carbon. Based on these findings, the study suggests
that utilizing PCC and UCA could potentially reduce carbon emission associated with cement or lime production while offering an opportunity to utilize this waste product in civil engineering
projects. Key Words: Precipitated Calcium Carbonate (PCC), Upcycled Recycled Concrete
Aggregate (UCA), Compressive Strength, Tensile Strength, Flexural Strength, Loess, Saturation
Collapse, X-ray diffraction (XRD), Energy dispersive X-ray spectroscopy (EDX). |