Fire performance of ductile fiber reinforced cementitious composites

Abstract

LIST OF TABLES IX LIST OF FIGURES XI CHAPTER 1. INTRODUCTION 1.1 BACKGROUND AND MOTIVATION 1.2 OBJECTIVES 1.3 THESIS LAYOUT CHAPTER 2. LITERATURE REVIEW 2.1 INTRODUCTION 2.2 FIRE PERFORMANCE OF DFRCC 2.2.1 Compressive properties of DFRCC after elevated temperature 2.2.2 Tensile properties of DFRCC after elevated temperature 2.2.3 Tensile properties of DFRCC at elevated temperature 2.2.4 Spalling resistance of DFRCC at elevated temperature 2.2.5 Sprayable lightweight DFRCC for fire protection 2.2.6 Thermal properties of DFRCC 2.3 FIRE-INDUCED SPALLING 2.3.1 Fire-induced spalling mechanism 2.3.2

Graphene oxide-coated Poly(vinyl alcohol) fibers for enhanced fiber-reinforced cementitious composites

“…Based on the mechanical test results of FRCCs, the enhancement at the interface between fiber and cementitious matrix was further quantified using a model designed by Victor.Li and colleagues for FRCCs [13,14,34]. As shown in Equation 1, the bridging stress contributed by fibers (𝜎 𝐵 ) could be regarded as the difference between the total stress of the FRCCs and the sum of the stress of the cement matrix (𝜎 𝑎 ) and the fiber prestress (𝜎 𝑝𝑠 ).…”

“…On the other hand, by considering the reinforcing effect, when 𝛿 = 0, 𝜎 𝐵 of PVA FRCCs could also be derived based on the fiber geometry and the interface between fiber and cement matrix, as shown in Equation 2 [13].…”

“…where 𝐺 𝑑 is the chemical bond energy between fiber and cement matrix, f is the snubbing coefficient [34,63], ranging from 0.5 to 0.9 for the PVA fiber [13], 𝐸 𝑓 and 𝑑 𝑓 are the elastic modulus and diameter of the PVA fiber respectively, and 𝜂 = 𝑉 𝑓 𝐸 𝑓 𝑉 𝑚 𝐸 𝑚…”

“…Fibers, especially those with low aspect ratio (generally less than 300), are often pulled out at the fracture surface [7][8][9]. From previous experimental and theoretical analysis, it is expected that the low improvement in the tensile strength is mainly attributed to insufficient bonding strength at the interface between fiber and matrix [10][11][12][13][14].…”

“…The enhancement at the interface was further investigated by a theoretical model for microsynthetic FRCCs [13,34]. On the basis of this model, the chemical bond energy (𝐺 𝑑 ) at the interface was quantified.…”