Utilization of Precipitated Calcium Carbonate (PCC) and Upcycled Concrete Aggregate (UCA) in Civil Engineering

The purpose of this study is to utilize Precipitated Calcium Carbonate (PCC) and Upcycled Concrete Aggregate (UCA) in civil engineering. PCC is a fine to coarse grain material generated during the production of sugar from sugar beets. UCA is produced from demolished and returned concrete by the extraction of primarily calcium and alkalinity. The test results on PCC alone show that the optimum content to achieve a minimum 28 MPa (4000 psi) compressive strength is up to 30% by weight of Portland cement. The corresponding compressive strength of mixes in which conventional aggregate was replaced by UCA is about 55 MPa (8000 psi) at water to cement ratio (0.44) by weight of Portland cement. The compressive strength of concrete with 25% to 30% cement replaced by PCC and varying amounts of aggregates replaced by UCA ranges from 19 MPa (2800 psi) to 40 MPa (5800 psi). Other tests on PCC and UCA include split tensile strength: 2 MPa (293 psi) to 3 MPa (423 psi) and flexural strength: 1 MPa (183 psi) to 2 MPa (279 psi). 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 X-ray 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 these materials in civil engineering projects.