Investigation of UHPC Columns for Stress-Strain Behaviour, Economic and Environmental Feasibility

Abstract

Ultra High Performance Concrete (UHPC) also known as Reactive Powder Concrete (RPC) was developed by in France circa 1995 (Richard & Cheyrezy, 1995). The most notable characteristics of RPC are its mechanical properties, which are an “ultra high” compressive strength (𝑓′𝑐 ≥ 150 𝑀𝑃𝑎), a high flexural strength (modulus of rupture) (𝑓′𝑐𝑓 ≥ 30 𝑀𝑃𝑎) and a high Young’s (Elastic) modulus (𝐸 ≥ 50 𝐺𝑃𝑎).

There seems to be a noticeable void in the research on UHPCs, that is on the utilization of UHPC in axial members (columns). Hence, a logical progression of research would be to consider the utilization of UHPC in columns, of which this study intends to explore.

Material Models (Gilbert & Gowripalan, 2000), are utilized to Numerically Analyze UHPC Column Sections to determine its Structural Performance specifically the Moment Capacity and Ductility of the section.

In this study, the viability of UHPC replacing High Strength Concretes (HSC) in Concrete Columns is explored. Parametric Studies are conducted to enable a better understanding of the structural performance of UHPC Columns, where both Normal Steel Rebars and Prestressing Strands are considered as Steel Reinforcement. An Environmental Feasibility Analysis and an Economical Feasibility Analysis are performed comparing the Environmental and Economic Viability of a Normal Strength Concrete (NSC) Column to a Structurally Equivalent UHPC Column.

This study has found that UHPC is viable for adoption by industry for use in columns when only structural performance and economy (viable in high value property with Non-Proprietary UHPC (Graybeal, 2013)) are considered. But more research needs to be done on replacing Component Materials in UHPC design mixes to lower the higher Embodied Carbon content of UHPC Columns compared to NSC Columns.