DEFORMATION PERFORMANCE IMPROVEMENT IN TIMBER COLUMN–GROUND SILL JOINT REINFORCED USING ARAMID FIBER SHEET

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Noriko Takiyama ◽  
Akari Yamaguchi ◽  
Xinyan Chen ◽  
Sho Koike
Keyword(s):  
Performance Improvement ◽  
Seismic Performance ◽  
High Performance ◽  
Deformation Property ◽  
Aramid Fiber ◽  
Bending Test ◽  
Failure Behavior ◽  
New Material ◽  
Timber Column ◽  
Fiber Sheet

We report the progress of an experimental study conducted to understand the seismic performance of a timber column–ground sill joint reinforced using an aramid fiber sheet, and to improve the deformation property of the reinforced joint. An aramid fiber sheet is a new material that weaves high-performance aramid fibers in one or two directions. In previous research, certain problems were found: (a) even when applying a similar reinforcement, the sheet did not necessarily demonstrate the same failure mode, and (b) when the sheet was peeled off in stretches, the joint is destroyed through brittleness. In this study, based on the preceding research, we proposed a new sheet-pasting method for an improvement in the deformation property, and conducted a bending test under cyclic loading for some column-ground sill joint specimens to verify the seismic performance and failure behavior. It was found that, by splitting the sheet, the problems of the preceding research are avoidable.

ANALYSIS OF TIMBER COLUMN-GROUND SILL JOINTS REINFORCED WITH IMPROVED ARAMID FIBER SHEETS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Akari Yamaguchi ◽  
Xinyan Chen ◽  
Noriko Takiyama
Keyword(s):  
High Performance ◽  
Aramid Fiber ◽  
Plastic Layer ◽  
Failure Behavior ◽  
Past Study ◽  
Compression Zone ◽  
Reinforced Plastic ◽  
Timber Column ◽  
Fiber Sheet ◽  
And Control

High-performance aramid fiber sheets are a new class of composite materials made up of weaved polyamide fibers. In this study, the seismic performance and failure behavior of timber column-ground sill joints reinforced with aramid fiber sheets were investigated. In a past study, we conducted bending tests under cyclic loading for three column-ground sill specimens. After reinforcing the specimens with aramid fiber sheets, the joint strength improved but was dependent on the method of attaching the sheet. It was found that the compression zone of the aramid fiber-reinforced plastic layer broke at the joint boundary. In this paper, we proposed an improvement in the method of attaching the fiber sheet to the joint. On the compression zone at the boundary of the joint, resin was not pasted onto the aramid fiber, the fiber was not cured, and the plastic layer was not formed. Therefore, we could solve some problems and control the failure of column-ground sill joints.

PERFORMANCE CONFIRMATION TEST FOR TIMBER COLUMN–GROUND SILL JOINTS REINFORCED WITH ARAMID FIBER SHEETS

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Akari Yamaguchi ◽  
Xinyan Chen ◽  
Noriko Takiyama
Keyword(s):  
High Performance ◽  
Aramid Fiber ◽  
Failure Behavior ◽  
Restoring Force ◽  
Simple Method ◽  
Bending Tests ◽  
New Class ◽  
Confirmation Test ◽  
Timber Column ◽  
Polyamide Fibers

High-performance aramid fiber sheets are a new class of composite materials composed of weaved polyamide fibers. This seismic performance and failure behavior of timber column–ground sill joints reinforced with aramid fiber sheets were investigated. We conducted bending tests under cyclic loading for three column– ground sill specimens. The maximum bending moments were estimated using a simple method and compared with the experimentally obtained moments. After reinforcement with aramid fiber sheets, joint strength improved but was dependent on the sheet-attaching form. Moreover, it is remarkable to break from peeling sheet. Further, the proposed sheet-attaching form (with widened crossing sheets) exhibited a higher restoring force than did the conventional form because of sheet is further away from the center of rotation.

scholarly journals Environmentally Friendly, High-Performance Fire Retardant Made from Cellulose and Graphite

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2400
Author(s):  
Leandra P. Santos ◽  
Douglas S. da Silva ◽  
Thais H. Morari ◽  
Fernando Galembeck
Keyword(s):  
High Performance ◽  
Raw Materials ◽  
Fire Retardant ◽  
Visual Observation ◽  
Flame Resistance ◽  
New Developments ◽  
New Class ◽  
New Material ◽  
Accredited Laboratory ◽  
Materials Used

Many materials and additives perform well as fire retardants and suppressants, but there is an ever-growing list of unfulfilled demands requiring new developments. This work explores the outstanding dispersant and adhesive performances of cellulose to create a new effective fire-retardant: exfoliated and reassembled graphite (ERG). This is a new 2D polyfunctional material formed by drying aqueous dispersions of graphite and cellulose on wood, canvas, and other lignocellulosic materials, thus producing adherent layers that reduce the damage caused by a flame to the substrates. Visual observation, thermal images and surface temperature measurements reveal fast heat transfer away from the flamed spots, suppressing flare formation. Pinewood coated with ERG underwent standard flame resistance tests in an accredited laboratory, reaching the highest possible class for combustible substrates. The fire-retardant performance of ERG derives from its thermal stability in air and from its ability to transfer heat to the environment, by conduction and radiation. This new material may thus lead a new class of flame-retardant coatings based on a hitherto unexplored mechanism for fire retardation and showing several technical advantages: the precursor dispersions are water-based, the raw materials used are commodities, and the production process can be performed on commonly used equipment with minimal waste.

scholarly journals Fast Preparation of High-Performance Wood Materials Assisted by Ultrasonic and Vacuum Impregnation

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 567
Author(s):  
Hong Yang ◽  
Mingyu Gao ◽  
Jinxin Wang ◽  
Hongbo Mu ◽  
Dawei Qi
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Mechanical Tests ◽  
Vacuum Impregnation ◽  
Natural Forests ◽  
Ultrasonic Pretreatment ◽  
Fast Growing ◽  
Before And After ◽  
New Material ◽  
Ft Ir

In the absence of high-quality hardwood timber resources, we have gradually turned our attention from natural forests to planted fast-growing forests. However, fast-growing tree timber in general has defects such as low wood density, loose texture, and poor mechanical properties. Therefore, improving the performance of wood through efficient and rapid technological processes and increasing the utilization of inferior wood is a good way to extend the use of wood. Densification of wood increases the strength of low-density wood and extends the range of applications for wood and wood-derived products. In this paper, the effects of ultrasonic and vacuum pretreatment on the properties of high-performance wood were explored by combining sonication, vacuum impregnation, chemical softening, and thermomechanical treatments to densify the wood; then, the changes in the chemical composition, microstructure, and mechanical properties of poplar wood before and after treatment were analyzed comparatively by FT-IR, XRD, SEM, and mechanical tests. The results showed that with ultrasonic pretreatment and vacuum impregnation, the compression ratio of high-performance wood reached its highest level and the MOR and MOE reached their maximums. With the help of this method, fast-growing softwoods can be easily prepared into dense wood materials, and it is hoped that this new material can be applied in the fields of construction, aviation, and automobile manufacturing.

Rutting Treatment Technology of Asphalt Pavement of Abrupt Slope Section in Heavy Load and High Temperature Zone

2011 ◽  
Vol 287-290 ◽  
pp. 858-861
Author(s):  
Hui Wang ◽  
Zhou Qing Zhao ◽  
Jian Zeng
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Polyester Fibre ◽  
Asphalt Mixture ◽  
Good Control ◽  
Treatment Technology ◽  
Heavy Load ◽  
Test Road ◽  
Overlay Design ◽  
New Material

Aiming at the characteristics of pavement rutting damage of test road under the condition of heavy load and abrupt slope, an overlay design scheme and a new overlay material with high performance was proposed. The new material is PG82 modified asphalt SMA-13 added polyester fibre which can significantly improve the high temperature performance of asphalt mixture under severe environment, and its strength and crack resistance are superior to normal SMA-13. Tracking survey of test road shows that the pavement performances keeps good and rutting is under good control. Therefore those measurements are successful and can be a reference to similar projects.

scholarly journals Experimental and Numerical Investigation on Shear Retrofitting of RC Beams by Prefabricated UHPFRC Sheets

2016 ◽  
Vol 2 (5) ◽  
pp. 168-179
Author(s):  
Kian Aghani ◽  
Hassan Afshin
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Fem Analysis ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Externally Bonded ◽  
High Performance Fiber ◽  
Bending Capacity

Different methods are used for retrofitting RC members. One of the new methods in this field is using externally bonded fiber-reinforced Concrete (FRC) sheets in order to increase RC member’s shear and flexural strength. In this study, applicability of ultra-high performance fiber-reinforced concrete sheets in shear and flexural retrofitting of RC beams was investigated. In total, eight RC beams (dimensions 10×20×150 cm) with two different bending capacity and lack of shear strength were used and were tested in 3-points bending test. Of these, four were control beams and four were retrofitted with laterally bonded UHPFRC sheets. Dimensions of the sheets used for retrofitting were (3×15×126 cm). Also FEM analysis was used to model the effect of The method. the results show that this method can be well used for retrofitting RC beams. In this method the way of connecting sheets to beam’s surfaces has a fundamental role in behavior of retrofitted beams.

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