On the tensile and shear strength of nano-reinforced composite interfaces

The properties of hybrid self-reinforced composite (SRC) materials based on ultra-high molecular weight polyethylene (UHMWPE) were studied. The hybrid materials consist of two parts: an isotropic UHMWPE layer and unidirectional SRC based on UHMWPE fibers. Hot compaction as an approach to obtaining composites allowed melting only the surface of each UHMWPE fiber. Thus, after cooling, the molten UHMWPE formed an SRC matrix and bound an isotropic UHMWPE layer and the SRC. The single-lap shear test, flexural test, and differential scanning calorimetry (DSC) analysis were carried out to determine the influence of hot compaction parameters on the properties of the SRC and the adhesion between the layers. The shear strength increased with increasing hot compaction temperature while the preserved fibers’ volume decreased, which was proved by the DSC analysis and a reduction in the flexural modulus of the SRC. The increase in hot compaction pressure resulted in a decrease in shear strength caused by lower remelting of the fibers’ surface. It was shown that the hot compaction approach allows combining UHMWPE products with different molecular, supramolecular, and structural features. Moreover, the adhesion and mechanical properties of the composites can be varied by the parameters of hot compaction.

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Bulk cure study of nanoclay filled epoxy glass fiber reinforced composite material

Journal of Polymer Engineering ◽

10.1515/polyeng-2015-0086 ◽

2017 ◽

Vol 37 (3) ◽

pp. 247-259

Author(s):

John Olusanya ◽

Krishnan Kanny ◽

Shalini Singh

Keyword(s):

Shear Strength ◽

Glass Fiber ◽

Weight Ratio ◽

Small Samples ◽

Fiber Reinforced ◽

Degree Of Cure ◽

Plane Shear ◽

Fiber Reinforced Composite ◽

Reinforced Composite ◽

Glass Fiber Reinforced

Abstract The correlation between cure properties and structure of nanoclay filled composite laminate has not been studied extensively. Most of the cure studies were preferably done using small samples through a calorimetric method. In this study, the effect of varying weight ratio of nanoclay (1–5 wt%) on bulk cure properties of epoxy glass fiber reinforced composite (GFRC) laminates was studied. Bulk cure of unfilled and clay filled GFRC laminates was determined using the dynamic mechanical analysis-reheat method (DMA-RM). DMA-RM cure properties gave a better coordinate method, with better cure efficiency achieved in clay filled GFRC laminates when compared to unfilled GFRC laminates. The correlation between nanoclay and DMA-RM degree of cure was coordinated with compressive and in-plane shear strength properties. The degree of cure value of 78% by DMA-RM at 1 wt% clay filled GFRC corresponds with the compressive modulus and in-plane shear strength highest values, which are 20% and 14% increase, respectively, also at 1 wt% clay filled GFRC. The structures of the unfilled and clay filled epoxy were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Clay filled epoxy up to 3 wt% showed no distinct diffraction peak, which suggested that nanoclay is randomly dispersed in the matrix.

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Fibre reinforced polymer strengthening of the Sainte-Émélie-de-l'Énergie bridge: design, instrumentation, and field testing

Canadian Journal of Civil Engineering ◽

10.1139/l00-028 ◽

2000 ◽

Vol 27 (5) ◽

pp. 916-927 ◽

Cited By ~ 24

Author(s):

P Labossière ◽

K W Neale ◽

P Rochette ◽

M Demers ◽

P Lamothe ◽

...

Keyword(s):

Shear Strength ◽

Composite Materials ◽

Bending Strength ◽

Field Testing ◽

Longitudinal Direction ◽

Concrete Bridges ◽

Repair Work ◽

Reinforcement Scheme ◽

Reinforced Composite ◽

Current Loading

An experimental research project was undertaken to evaluate the need to strengthen existing reinforced concrete bridges belonging to the Ministère des Transports du Québec. A typical bridge consisting of a single-span bridge with T-shaped sections was identified. Evaluation of the bridge showed that an increase in bending strength and shear strength would be necessary to satisfy current loading conditions and code requirements. The increase in bending strength was obtained by bonding carbon-reinforced composite materials to the underface of the beams, with fibres in the longitudinal direction. External U-shaped stirrups made of glass-reinforced composite materials were installed on the outside faces of the beams in order to increase their shear strength. This paper presents a selection of experimental results initially obtained on T-section beams, scaled 1:3 with respect to the bridge under consideration. The actual reinforcement scheme selected for the bridge is then presented, accompanied by comments on the construction process. Conventional instrumentation and fibre optic sensors were incorporated to the repair work in order to evaluate the behaviour of the bridge, before and after strengthening. Initial results of this ongoing evaluation are presented here.Key words: bridge strengthening, FRP, composite materials, instrumentation, field testing.

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