Speaker: Niaz Md Ashraful Haque
When: May 1st, 2025, at 9:00AM
Where: PKI 250 (Omaha)
Zoom: https://unl.zoom.us/j/99938130838
Title: Evaluation of Mechanical and Durability Properties of Concrete Incorporating CO₂-Treated Recycled Concrete Aggregates
Abstract: The use of recycled concrete aggregate (RCA) is gaining traction as a sustainable alternative to natural aggregates, though performance limitations as high porosity, residual mortar, and reduced mechanical strength remain a concern. This research investigates the application of CO₂ carbonation to enhance RCA quality, using materials from multiple infrastructure sources treated under both mid-scale and industrial-scale conditions. Results showed significant improvements in RCA properties, including reduced water absorption and aggregate crushing value (ACV), along with enhanced freeze-thaw resistance. Concrete made with treated RCA exhibited improved mechanical strength and durability against freeze-thaw cycles, shrinkage, and chloride ion penetration, meeting or exceeding Nebraska DOT (47B) specifications. Field validation at pavement sections in Lincoln and Omaha confirmed laboratory findings, establishing CO₂-treated RCA as a scalable, durable, and sustainable solution for pavement construction.