Work

Supplementary Cementitious Materials Based on CO 2 –Capturing Periwinkle Shell

Year: 2025

Type: supplementary-materials

Abstract: High Resolution Image Download MS PowerPoint Slide Recently, cool concrete incorporating carbonated periwinkle shell ash (CPSA) aggregates, a marine-waste-derived material, has been explored to enhance the thermal reflectivity of concrete for heat island mitigation. This work provides the first detailed evaluation of the CPSA behavior within cementitious systems. An accelerated carbonation process was optimized to convert periwinkle shell ash (PSA) into stable calcite within 15 min under ambient conditions, achieving a CO 2 uptake efficiency of 91.6 wt %. This rapid mineralization arises from the presence of reactive Ca phases in PSA, which facilitates fast CO 2 diffusion. CPSA was incorporated into cement pastes at binder replacement levels of 67–87 wt % to evaluate its hydration behavior, microstructure, and mechanical properties. Key findings showed that the calcite formed during carbonation acts as a filler and nucleation site, accelerating hydration, refining the pore structure and promoting a denser microstructure. Adequate performance was maintained up to 77 wt % replacement, with a dynamic elastic modulus of 11 GPa, comparable to the OPC control. Water adsorption studies revealed that CPSA retained up to 16 wt % water within 1 week, influencing workability and hydration. CPSA emerges as a CO 2 -sequestering material with inherent solar reflectance and cementitious performance, offering dual environmental and structural benefits.

Source: ACS Sustainable Resource Management

DOI: 10.1021/acssusresmgt.5c00313

Authors: Ebtisam Saeed, Mary B. Ogundiran, Guido Goracci, Cyril Aymonier, Jorge S. Dolado