Biochar modification enhances mechanical and durability properties of cement-based materials

Area of Science:

• Materials Science
• Environmental Engineering
• Civil Engineering

Background:

• Cement manufacturing contributes to carbon imbalance and environmental risks.
• Biochar materials offer a sustainable alternative for cement composites.
• Integrating biochar can mitigate CO2 emissions and provide economic benefits.

Purpose of the Study:

• To investigate the effects of biochar derived from apricot, palm, date, and peach shells as cement replacement in concrete.
• To evaluate the impact of biochar on the workability, density, compressive strength, drying shrinkage, and permeability of ultra-high performance concrete (UHPC).

Main Methods:

• Replacing cement with 0.1-24% apricot shell biochar and 8% palm, date, and peach shell biochar.
• Assessing workability, density, compressive strength, drying shrinkage, and anti-permeability of biochar-mortar admixtures.
• Utilizing MIP and SEM analyses to examine porosity and hydration products.

Main Results:

• Workability and density showed a nearly linear decline with biochar addition.
• Peak compressive strength was achieved with 1% biochar, exceeding the control by 2.65%.
• Reduced drying shrinkage and improved anti-permeability were observed for biochar additions between 0.1-2%.

Conclusions:

• Biochar as an additive in UHPC mortar shows potential for waste recycling and carbon sequestration.
• Optimal biochar content (around 1%) leads to enhanced mechanical properties and reduced porosity in UHPC.
• Biochar integration offers a viable strategy for developing sustainable building materials.