Title:
Mixture Design of Sustainable Nano-Engineered High-Performance Concrete (nHPC) Overlay for Concrete Bridge Decks in Cold Regions
Author(s):
Jialuo He
Publication:
Web Session
Volume:
ws_F23_XianmingShi-JialuoHe.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
10/29/2023
Abstract:
Ultra-high-performance concrete (UHPC) overlay is a highly promising solution of concrete bridge deck rehabilitation for its superior mechanical properties and durability. However, the high cement content in UHPC significantly increases its cost and carbon footprint and the low water-to-binder (w/b) ratio leads to autogenous shrinkage. Besides, the high compressive strength of UHPC (> 150MPa) might be over-design for the bridge deck overlay application. This study aims to develop a new type of sustainable nano-engineered high-performance concrete (nHPC) with lower initial cost, lower cement content, sufficient strength (> 69MPa), and comparable durability. There are multiple supplementary cementitious materials (SCMs, i.e., class F/C fly ash, limestone powder, and silica fume), fiber reinforcements (i.e., steel fiber and synthesis fiber), and nano material (i.e., montmorillonite) in the nHPC mixture. By employing the mix design method for cost-effective UHPC with central composite design, the optimal weight contents of each component in the nHPC mixture can be determined in accordance with the associated demand of high-range water reducing admixture, 7-day/28-day compressive strength, and thixotropy. The expected initial material cost of nHPC will be no more than 4.0 $/m3/MPa. In addition, the shrinkage, transport properties, and bond strength of nHPC are tested for comparison with that of UHPC.