International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 12 Issue: 05 | May 2025
p-ISSN: 2395-0072
www.irjet.net
Study on the Mechanical Properties of Carbon Dioxide Mineralization-Cured Alkali-Activated Rice Husk Ash Cementitious Composites Ningxin Huang1，Xinyong Wei1，Yibo Mao1，Yu Pang1 (1. School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, Anhui 232001, China;) ---------------------------------------------------------------------------***---------------------------------------------------------------------Abstract: To investigate the mechanical properties of alkali-activated rice husk ash cementitious composites under Carbon Dioxide mineralization curing, this study systematically examined the effects of rice husk ash (RHA) content (0%, 5%, 7%, 10%), Carbon Dioxide mineralization curing duration (0, 60, 120, 200 min), and freeze-thaw cycles (0, 5, 15, 30) on compressive strength and durability through uniaxial compression tests and freeze-thaw resistance experiments. Microstructural evolution mechanisms were elucidated via X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results demonstrate that specimens with 5% RHA content and 120 min Carbon Dioxide mineralization curing, activated by a sodium silicate solution (modulus = 2), achieved a 28-day compressive strength of 32.18 MPa, representing a 37.79% enhancement compared to the control group. After 30 freeze-thaw cycles, the strength loss rate remained below 23%. XRD and SEM analyses revealed that calcite (Calcium Carbonate) generated during Carbon Dioxide mineralization filled pore structures, inhibiting frost damage by reducing water penetration, while amorphous Silicon Oxide in RHA facilitated continuous pozzolanic reactions to form C-S-H gels, establishing a synergistic frost resistance mechanism. This research provides theoretical and technical insights for developing low-carbon building materials in cold regions. Non-linear relationships were observed between material performance and key parameters: compressive strength and freeze-thaw resistance initially increased and then decreased with prolonged mineralization duration, whereas increasing RHA content induced an initial decline followed by subsequent improvement in performance. Keywords: Mineralization curing; Alkali activation; Rice husk ash; Cementitious composites; Freeze-thaw cycles; Mechanical properties; Microstructural mechanisms 1. INTRODUCTION In recent years, the global construction industry has faced significant challenges in pursuing sustainable development. In 2021, China's construction sector accounted for 4.07 billion tons of carbon emissions, with cement production alone contributing 7% of global carbon emissions due to its high energy consumption and substantial Carbon Dioxide release, exacerbating greenhouse effects and environmental degradation. Driven by the "dual-carbon" objectives (carbon peaking and carbon neutrality), the development of low-carbon cementitious materials and carbon capture/utilization technologies has emerged as a pivotal strategy for the transformation of the building materials industry. China produces over 40 million tons of rice husk annually. While direct incineration of rice husk generates underutilized ash with adverse environmental impacts, calcined rice husk ash (RHA)—after organic component removal—exhibits chemical and physicochemical properties comparable to reactive supplementary cementitious materials like silica fume, offering a cost-effective and abundant alternative to conventional cement. However, traditional curing methods fail to fully exploit its potential. Carbon Dioxide mineralization curing technology, which converts Carbon Dioxide into stable carbonate minerals via reactions between alkaline cementitious materials and Carbon Dioxide to form calcite (Calcium Carbonate), enables permanent Carbon Dioxide sequestration while enhancing the early-age strength and durability of cement-based composites. © 2025, IRJET
|
Impact Factor value: 8.315
|
ISO 9001:2008 Certified Journal
|
Page 1264