Efficiency of a polycarboxylate superplasticizer and low water content in improving the performance and reducing the carbon footprint and cost of cement-wood biochar mortar

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Demonstrates a balanced optimization of cost, strength, and carbon footprint for biochar-incorporated cement mortar. Useful for developing low-carbon concrete formulations.

🏢実務担当者:Provides specific dosage and water ratio guidelines to reduce CO2 emissions by 15% without compromising performance, aiding sustainable product development.

🏛政策担当者:Supports policies promoting biochar as a construction material with clear cost and emission trade-offs, informing carbon credit or green procurement rules.

Although biochar is a promising admixture, its use can alter the workability and mechanical strength at certain low cement substitution rates. Using a superplasticizer (SP) is an effective solution, but more is required as the biochar content increases, which can increase costs and the carbon footprint. This study evaluated the efficiency of adjusting the SP dosage while maintaining or reducing the water-to-binder ratio (w/b) in order to optimize the key properties of mortars containing cement blended with biochar, compared to standard mortar (100% cement, standard sand and 0.5 w/b). A cost and environmental impact assessment was conducted to determine the potential reduction in CO 2 emissions and cost of optimized mortar mixtures. The results showed that, at a w/b ratio of 0.5, to maintain the same price as the reference mortar, the cost of the biochar, SP dosage and biochar rate should not exceed 53 €/ton, 0.2 wt% and 5 wt%, respectively. Although mortars containing 10 wt% biochar had a similar workability to the reference mortar, they exhibited increased porosity, resulting in a 13% reduction in compressive strength. However, at a w/b ratio of 0.44, the addition of 10 wt% biochar and 0.7 wt% SP, enhanced hydration, and reduced porosity, thereby increasing compressive strength relative to cement content in addition to reducing CO₂ emissions by 15% (per m 3 of mortar). This resulted in a greater strength-to-cost-to-carbon performance ratio than that of the reference mortar (1.45 vs. 1.24 MPa.m 3 /k€.kg CO 2 eq.). The improvement in this performance ratio was observed even in worst-case scenarios, where the price of biochar was assumed to equal that of cement and its global warming potential was considered to be zero rather than negative (1.26 vs. 1.24 MPa.m 3 /k€.kg CO 2 eq.), thanks to gains in environmental impact and compressive strength.

• openalex https://doi.org/10.1016/j.conbuildmat.2026.147196first seen 2026-06-27 04:53:18