Engineered Blended Thermoactivated Recycled Cement: A Study on Reactivity, Water Demand, Strength-Porosity, and CO2 Emissions
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Annually, 1 Gt of cement waste is produced, constituting one-fourth of recent cement production and surpassing the availability of most supplementary cementitious materials (SCMs). It is known that the thermoactivation of cement waste (heating to 500 °C to drive off water molecules and hydroxyl units) recovers cement reactivity. However, from literature we show that this reactivity is insufficient for adequate strength gain due to the high surface area and, hence, high water demand of thermoactivated recycled cement (RC). Instead, as proposed herein, RC used as the dominant component (>75% wt) within an optimized particle packing system (<20% wt of micronized Portland cement) yields an engineered recycled cement (eRC) with comparable early- and late-age strength gain behavior to ordinary Portland cement (OPC). Evaluation of CO 2 emissions reveals that eRC emits 198–320 kgCO 2 /t, which is substantially lower than that of scalable blended Portland cements. Deploying this technology together with other strategies, such as CO 2 capture by carbonation of cement waste, can mitigate 61% of projected 2050 CO 2 emissions of the cement industry (2.31 Gt of CO 2 /year).
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4405848901