HIGH PERFORMANCE AND ULTRA HIGH PERFORMANCE CONCRETE WITH LOCALLY AVAILABLE MATERIALS FROM SASKATCHEWAN

Abstract

Reinforced concrete structures exhibit various durability problems, such as the corrosion of reinforcing steel, sulfate attack, etc., when exposed to harsh environments. This type of damage often leads to very serious technical and economic problems, such as a short lifetime of infrastructure and high costs associated with their long term maintenance and repair. High performance concrete (HPC) and ultra-high performance concrete (UHPC) could play key roles in solving or in mitigating these problems. The main research goal of this thesis was to determine whether it is possible to produce high performance concrete (HPC), very-high performance concrete (VHPC) and ultra-high performance concrete (UHPC) that have unique combinations of strength, freeze-thaw durability and self-placeability at competitive costs using materials locally available in Saskatchewan. To develop HPC and VHPC/UHPC, a statistical experimental design was used to perform experimental designs, analyze the fitting models and optimize multiple responses. The procedure was implemented using the Design-Expert Version 9.0 software. Seven materials were researched in this project to make concrete, namely: water, cement, silica fume, silica flour, fine sand, steel fiber, and superplasticizer (SP). Four different properties were measured, including the compressive strength, splitting tensile strength, air content of hardened concrete and flow cone test. After analyzing the results of these tests, it was found that the goal of developing a HPC material with the specified properties was achieved (flow cone spread value = 274 mm and, after 28 days, the obtained properties were: compressive strength = 82 MPa, splitting tensile strength = 23 MPa and air content = 6%.). The goal of making VHPC with the specified properties was obtained (flow cone spread value = 274 mm and, after 28 days, the obtained properties were: compressive strength iv = 102.4 MPa and splitting tensile strength = 23 MPa) regardless of air content. Nevertheless, the results of the analysis clearly showed that it would be impossible to produce a UHPC with a 28 day compressive strength greater than 150 MPa using the mix ingredients and fabrication processes adopted in this study.