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Strengthening mechanical properties of glulam with Basalt Fiber.

INTRODUCTION

Timber is the most ancient and widely used traditional construction material. Glued laminated (glulam) timber material has been in existence since the 1800s [1]. It has been used in numerous applications including arches for airplane hangers, timber for floors, dome structures, timber bridge decks etc.

The earliest recorded studies on wood beams reinforced with fibre and FRP FRP Fremskrittspartiet (Norwegian: Progress Party; political party)
FRP Fiberglass-Reinforced Plastic
FRP Fiber Reinforced Polymer
FRP Fibre Reinforced Polymer
FRP Fleet Response Plan (US Navy) 
 materials were in 1964 and 1965 by Wangaard [2] and Biblis [3] respectively when they studied the effect of bonding unidirectional fibre-glass/ epoxy reinforced plastic to the compression and tension faces of wood cores of various species and Theakson [4] in 1965 studied the feasibility of strengthening both laminated and solid wood beams with fibre-glass. In 1974, Krueger [5] studied laminated timber reinforced in the tension zone with a composite of high-strength bronze coated woven steel wire and epoxy. Later in 1981, Spaun [6] studied finger-jointed western hemlock hemlock, any tree of the genus Tsuga, coniferous evergreens of the family Pinaceae (pine family) native to North America and Asia. The common hemlock of E North America is T.  cores reinforced with wood veneers and fibre-glass roving.

By the 2000s, better enhanced FRP composites called hybrid FRP and Ultra hybrid FRP composites were being developed and more research work into their uses were made. Fiorelli and Dias in 2002 [7] analysed the strength and stiffness of timber beams reinforced with carbon fibre and glass fibre composites. Lopez-Anido and Xu [8] that same year published work they had done on the structural characterization of hybrid FRP-glulam panels for bridge decks.

In 2006 Dempsey and Scott [9] studied the effects of mechanically fastening FRP strips to wood members as a strengthening feature. That same year, Johnsson, Blanksvard and Carolin [10] worked on some glulam members strengthened by carbon fibre reinforcement by first running pull-out tests on four pairs of glulam members at four different anchoring lengths.

Xiongchen Fu studied the bonding performance between BFRP BFRP Boron Fiber Reinforced Plastics
BFRP Business Function Recovery Plan
 (Basalt fiber Basalt fiber or fibre is a material made from extremely fine fibers of basalt, which is composed of the minerals plagioclase, pyroxene, and olivine. It is similar to carbon fibre and fiberglass, having better physicomechanical properties than fiberglass, but being  reinforced polymer) and timber [11], the results shows that: the treatment of wood surface greatly enhanced the bonding performance between BFRP and wood composite materials by HMR HMR Hazardous Materials Regulations
HMR Human Resources
HMR Home Meal Replacement
HMR Hamrun (postal locality, Malta)
HMR Hôpital Maisonneuve-Rosemont (Montréal, Canada) 
(hydroxy hy·drox·y  
adj.
Containing the hydroxyl group.



[From hydroxyl.]


hydroxy  

Containing the hydroxyl group (OH).

Adj. 1.
 methylated resorcinol resorcinol /re·sor·ci·nol/ (re-zor´si-nol) a bactericidal, fungicidal, keratolytic, exfoliative, and antipruritic agent, used especially as a topical keratolytic in the treatment of acne and other dermatoses. ). The stripping rate reached 0.00% to 1.03% on the layer between wood composite and the BFRP which is treated by HMR, and it reached the ASTM ASTM
abbr.
American Society for Testing and Materials
 D2559 standard requirements (outdoor structure with a laminated strip ratio <1%).

In 2008, Li Yunfeng, etc. studied the bonding performance of BFRP-Structural laminated timber, the results shows that the time is a greatly important factor for the bonding performance of BFRP-Structural laminated timber, while the unit pressure and the amount of glue still need further test to be determined [12]. In 2010, Li Long, Zhang Peng-Yi studied the bonding performance of BFRP-bamboo-wood composite laminated glulam, the large daters shows the optimum gluing process of BFRP-bamboo-wood composite laminated glulam by Polyurethane adhesive [13].

1. MATERIALS

1.1 Basalt basalt (bəsôlt`, băs`ôlt), fine-grained rock of volcanic origin, dark gray, dark green, brown, reddish, or black in color. Basalt is an igneous rock, i.e., one that has congealed from a molten state.  FRP

The bonding experiment used was Basalt Fiber, which is a basalt fiber directional sheet, of thickness 1.4[+ or -]0.01mm made by Hicome in Nanjing, and designed for the strengthening of structural members against tensile, shear and impact forces. The mechanical properties of the basalt fiber had been measured in the experiment. The sheet is supplied with Vinyl resin Noun 1. vinyl resin - a thermoplastic derived by polymerization from compounds containing the vinyl group
polyvinyl resin, vinyl polymer

polyvinyl acetate, PVA - a vinyl polymer used especially in paints or adhesives
 and forms the Basalt Fiber Externally Bonded Reinforcement System.

1.2 Laminates

The strengthened glulam material consisted of 48 Larch laminate sections, prepared for bonding experiment and flexural flexural

pertaining to the flexure of a joint.


flexural deformity
fixation of joints in flexion. In the newborn called contracted calves or foals.
 testing; 24 samples were cut in lengths of 1000mm with widths 50 mm, and other 24 samples were cut in lengths of 500mm with widths 50 mm The thickness of the laminate material used was 25mm, which is provided by IKEA IKEA Ingvar Kamprad Elmtaryd Agunnaryd (Swedish home furnishings retailer founder's initials and location)  Wood in Mohe.

1.3 Adhesives and Coupling Agents

Two types of adhesives were prepared, one is Resorcinol Adhesive, and the other is Polyurethane Adhesive. Both were provided by related company. Coupling agent is constituted by Formaldehyde, Sodium dodecyl sulfate Sodium dodecyl sulfate (or sulphate) (SDS or NaDS) (C12H25NaO4S),is an anionic surfactant that is used in household products such as toothpastes, shampoos, shaving foams and bubble baths for its thickening effect and its ability to , Sodium hydroxide sodium hydroxide, chemical compound, NaOH, a white crystalline substance that readily absorbs carbon dioxide and moisture from the air. It is very soluble in water, alcohol, and glycerin. It is a caustic and a strong base (see acids and bases). , Resorcinol, and water. They were purchased in the chemical store.

2. SPECIMENS PREPARATION

The laminate materials were cut to sizes consisting three beam members for width and cleaned with aid of a sharp sand paper to ensure a flat, clean and degreased surface. Saw dust particles were removed with the aid of a hand vacuum cleaner. Likewise, the BFRP reinforcing material was cut to the same widths as the beams and vacuumed ready for application.

The coupling agent was made up at the specified ratio, and then, the coupling agent applied with the aid of a roller onto the surface of BFRP and laminate materials. They were then left to place in the next 24 hours.

The BFRP was then placed onto the tension face of the ply beam at equidistance e·qui·dis·tant  
adj.
Equally distant.



equi·distance n.
 from the beam centre line and set firmly onto the substrate using a suitable hand roller. The specimens were then formed on through different bonding processes. The following picture is a schematic diagram of the Bonding Process.

[FIGURE 1 OMITTED]

3. TEST PROCEDURES

Six groups BFRP samples in universal mechanical testing machine for BFRP bending, inter-laminar shear, tensile test, which is shown in Figure 2, the inter-laminar shear performance of BFRP. The loading rate is 2mm per minute.

[FIGURE 2 OMITTED]

Each beam was placed on the inverted test rig on a clear base. The Strengthening side is close to the steady. An external load was applied on the either side of the beam centre line. A picture of the beam test arrangement is placed in Fig. 3. The beams were loaded to failure on the three point bending test apparatus; the load rate was 3mm per minute.

[FIGURE 3 OMITTED]

4. TEST RESULTS

Results from the first test showed that the mechanical properties of the basalt fiber had a good performance. The average Inter-layer strength was 252.69MPa, the average tensile strength was 940.00MPa, and the average bending strength was 1011.20MPa. Fig. 1 shows the process of testing.

Results from the second test showed that BFRP timber can significantly enhanced the elastic modulus and bending strength, while the corresponding deflection reduced, which is shown in Figure 4 and Table 2.

Statistics show that, the average tensile strength parallel to grain can reach 90MPa and the bending strength is about 90MPa for China's timber, while results show that the average tensile strength parallel to grain of Basalt Fiber can reach 940MPa, and the bending strength is 1011.20MPa. Therefore, it is greatly active and effective to use BFRP for enhancing the mechanical properties. And the results also proved the same conclusion.

Tests show that the strength of BFRP reinforced timber increased by 10% than the unreinforced timber, while the deflection of the specimen reduced by 16% under the conditions of the resorcinol adhesive. And the strength of BFRP reinforced timber increased by 15% than the unreinforced timber, while the deflection of the specimen reduced by 16% under the conditions of the resorcinol adhesive. This proves that the basalt fiber reinforced structural glulam effectively.

CONCLUSIONS

This paper has presented experimental results aimed at establishing the effectiveness of BFRP composite systems flexural strengthening of glulam beams. Two alternative length measurements and two different types of adhesive for the upgrading system have been investigated.

All twenty-four plywood beams were subjected to three-point loading and the upgraded ply beam lengths reached and exceeded the plastic collapse load of like-width un-strengthened ply beams.

Further investigations are currently pursued to examine various beam widths, strengthened with more than one layer of BFRP composites hoping to further improve the beam properties.

[FIGURE 4 OMITTED]

DOI (Digital Object Identifier) A method of applying a persistent name to documents, publications and other resources on the Internet rather than using a URL, which can change over time. : 10.3968/j.ans.1715787020110402.137

REFERENCES

[1] Dagher, H. J., Kimball, T. E., Shaler S. M., & Abdel-Magid, B. (1996). Effect of FRP Reinforcement on Low Grade Eastern Hemlock eastern hemlock

cicutamaculata.
 Glulams. Proceedings of National Conference on Wood Transportation Structures, pp. 207213.

[2] Wangaard, F. (1964). Elastic Deflection of Wood-Fiberglass Composite Beams. Forest Product Journal, 14, 256-260.

[3] Biblis, E. J. (1965). Analysis of Wood-Fiberglass Composite Beams Within and Beyond the Elastic Region. Forest Product Journal, 15, 81-88.

[4] Theakston, F. H. (1 965). A Feasibility Study "A Feasibility Study" is an episode of the original The Outer Limits television show. It first aired on 13 April, 1964, during the first season. It was remade in 1997 as part of the revived The Outer Limits series with a minor title change.  for Strengthening Timber Beams with Fibreglass. Canadian Agricultural Engineering Journal, (1), 17-19.

[5] Krueger, G. P. & Eddy, F. M. (1974). Ultimate Strength Design of Reinforced Timber: Moment-Rotation Characteristics. Wood Science, 6, 330-344.

[6] Spaun, F. D. (1981). Reinforcement of Wood with Fibreglass. Forest Products Journal, 13, 26-33.

[7] Fiorelli, J. & Dias, A. A. (2003). Analysis of the Strength and Stiffness of Timber Beams Reinforced with Carbon Fiber and Glass Fiber. Materials Research, (4-5), 6.

[8] Lopez-Anido, R. & Xu, H. (2002). Structural Characterization of Hybrid Fiber-Reinforced Polymer-Glulam Panels for Bridge Decks. Journal of Composites for Construction,-ASCE, 6, 194-203.

[9] Dempsey, D. D. & Scott, D. W. (2006). Wood Members Strengthened with Mechanically Fastened FRP Strips. Journal of Composites for Construction,-ASCE, 10, 392-398.

[10] Johnsson, H., Blanksvard, T., & Carolin, A. (2006). Glulam Members Strengthened by Carbon Fibre Reinforcement. Materials and Structure-ASCE, 40, 47-56.

[11] FU Xiongchen & SHEN Shijie (2005). Basalt Continuous Fiber Reinforced Plastic (BFRP) / Wood Composites. (Master's thesis). Beijing Forestry University Beijing Forestry University (Simplified Chinese: 北京林业大学) is one of the key national forestry institutes in China. It is directly administered by the Ministry of Education of the People's Republic of China. , Beijing, China.

[12] LI Yunfeng, SHEN Shijie (2009). The Study of Basalt Fiber Reinforced Structural Timber-One-Component Polyurethane Glue Technology Research. (Master's thesis). Beijing Forestry University, Beijing, China.

[13] LI Long & SHEN Shijie (2011). The Technology Research of Basalt Fiber Reinforced Laminated Larch Timber. Forestry Machinery and Woodworking Equipment, 3, 31-36.

ZHANG Pengyi (1) *; SHEN Shijie (2); MA Chunmei (1)

(1) M.A. Major: Wood Science and Technology. Beijing Forestry University, Beijing, China

(2) Professor, Major: Wood Science and Technology, Beijing Forestry University, Beijing, China Corresponding author.

Received 17 September 2011; accepted 19 November 2011
Table 1
Average BFRP Mechanical Properties Results from
Experiments

Samples        Bending         Bending        Tensile        Tensile
              Modulus of      Strength       modulus of      Strength
           Elasticity (GPa)     (MPa)     Elasticity (GPa)    (MPa)

1               45.35          1004.74         46.33          947.78
2               39.14           940.65         47.91          974.83
3               42.61          1003.95         43.95          940.86
4               44.67          1073.60         50.09          944.76
5               42.10           999.30         47.55          921.92
6               45.51          1045.38         46.03          873.84
Average         43.23          1011.27         46.98          934.00

Results from the second test showed that BFRP
timber can significantly enhanced the elastic modulus
and bending strength, while the corresponding deflection
reduced, which is shown in Figure 4 and Table 2.

Table 2
Average Failure Load and Deflection Results from
Experiments

The type       Specimen       Average Failure   Average Deflect
of adhesive    Description         Load           at Failure

Resorcinol     76x50x500mm        14.52kN           7.39mm
adhesive       control
               76x50x500mm        16.74kN           6.62mm
               BFRP
               76x50x1000mm       11.20kN           15.20mm
               control
               76x50x1000mm       13.19kN           12.10mm
               BFRP

Polyurethane   76x50x500mm        18.39kN           6.78mm
adhesive       control
               76x50x500mm        19.06kN           5.24mm
               BFRP
               76x50x1000mm       16.11kN           13.52mm
               control
               76x50x1000mm       17.97kN           11.09mm
               BFRP
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Author:Pengyi, Zhang; Shijie, Shen; Chunmei, Ma
Publication:Advances in Natural Science
Article Type:Report
Geographic Code:9CHIN
Date:Dec 31, 2011
Words:1755
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