外文文献及译文玻璃纤维对于沥青稳固性影响的研究.docx

1、外文文献及译文玻璃纤维对于沥青稳固性影响的研究唐 山 学 院毕 业 设 计外文资料翻译 系 别： 土木工程系 班 级： 07级土木工程（2）班 姓 名： 赵 菲 指 导 教 师： 贾开武 2006年6月13 日一.英文原文A STUDY ON THE EFFECT OF GLASS FIBRE ON THE STABILITY OF BITUMINOUS MIXESS. JAYALEKSHMI1 and N. ANJANEYULUABSTRACT: Surface cracking of pavements decreases its fatigue response. The inclusi

2、on of glass fibre in bituminous mixes increases the fatigue life of pavements. In the current investigation E glass fibre is mixed with the bituminous mixes and Marshall Stability test was conducted. The optimum bitumen content and flow value were evaluated. The influence of this glass fibre on dura

3、bility and the engineering properties of semi dense bituminous concrete such as stability, flow, air voids in the mix, voids in mineral aggregates and voids filled with bitumen are presented in this paper. The stability values increased by as much as 32%.KEYWORDS: Fibre Glass, Bituminous Mixes, Mars

4、hall Stability Test, Stability, Flow Value1. INTRODUCTION The low tensile strength of bituminous mixes causes the pavement subjected to repeated loading to crack. The propagated cracks develop distress symptoms like raveling, undulations, rutting, cracking, bleeding, shoving and potholing of bitumin

5、ous surfacing. The high traffic intensity of commercial vehicles also compounds this problem. Hence, to improve the performance of the pavements, reinforcements and additives are added to the bituminous mixes. Therefore, there arises a necessity to evaluate the optimum fibre content and the type of

6、fibre. The fibres placed in the bituminous mix are homogeneously dispersed and act as stress absorbing layers. In the recent past, cotton, metal wire and asbestos were used. Cotton is degradable and cannot be used as long term reinforcement; metal wire rusts when water penetrates. Asbestos poses hea

7、lth hazard. This automatically leads to the choice of glass fibre. Transportation is the lifeline of any nations economy and hence improving the performance of the pavements indirectly boosts the economy.2. REVIEW OF LITERATURE Freeman (1978) found that the incorporation of polyester fibre as a rein

8、forcement in the surface course, reduces reflective cracking. The effect was studied by varying the diameter, length and percentage of the polyester fibre. Gokhale (1987) carried out studies on reinforced bituminous surfaces with fibre glass sheet and Teflon sheets and with five types of gradations

9、of mineral aggregates. Kim (1999) evaluated the performance of polymer - modified (polypropylene film and a grid) bituminous mixtures and specially designed reinforcing technique against reflective cracking for typical bituminous pavement over layers. The wheel tracking test was used to investigate

10、durability aspects such as the plastic flow resistance and crack resistance of the geogrid reinforced bituminous mixtures by Komatsu(1998). The material used was a high strength, high modulus polyoxymethylene fibre. As per Lytton (1989), the use of geotextiles in bituminous overlays enhances reinfor

11、cing, strain relief and under sealing. The reflection cracking caused by the loads and thermal contraction was arrested by the use of geotextile reinforcement. Maurer (1989) determined the effectiveness of various geotextiles and fibres in retarding the reflective crack formation in bituminous overl

12、ay. The fatigue life and the rut resistance also improved. The cheapest type of glass fibre available commercially is the E-Glass Fibre and this material is used in the present study as reinforcement within the bituminous mix.3. LABORATORY STUDY MATERIAL PROPERTIES3.1.1 Glass FibreThe properties of

13、the E-Glass Fibre used are as listed in Table 1.3.1.2 Aggregate The aggregate used in the study is of the gradation specified by the MORT&H (Specifications for Road and Bridge Works (2001) for 25 - 30 mm thick Semi-Dense Bituminous Concrete (Grade II). This is the most widely used surface course for

14、 highways in India. Tests conducted on the aggregate showed the material properties indicated in Table 2. Correct sampling (Representative sample) was ensured as correctness of the Marshall Stability Test largely depends on proper sampling. The required gradation was arrived at by batch mixing by ca

15、refully proportioning two or three sizes of aggregate mixtures. The nominal size of the aggregate is 10 mm. The layer thickness is 25 mm - 30 mm. The gradation is as shown in Table 3. The Semi Dense Bituminous Pavement Layers have a minimum stability of kN at 60. The flow is 2 mm to 4 mm. Compaction

16、 is achieved by giving 75 blows on each of the two faces of the specimen. The percentage of air voids is 3 - 5. The percentage of voids filled with bitumen is 65 - 78.3.1.3 Bitumen The engineering properties of Bitumen used in the study are listed in Table 4. Both 60/70 grade bitumen and 80/100 bitu

17、men were used in the study.4. METHODOLOGY Bitumen and aggregate form the major constituents of the surface layer of a flexible pavement. The following properties were evaluated. Bitumen: Penetration, softening point, ductility, specific gravity. Aggregate: Crushing value, impact value, abrasion valu

18、e, flakiness index, elongation index, water absorption, specific gravity. Gradation of Semi Dense Bituminous Concrete usually used for surface layers of the flexible pavements in India has been selected for the present study. All the tests were performed according to the standards. Marshall Method o

19、f mix design was carried out on glass fiber reinforced and unreinforced bituminous mixes to arrive at optimum fiber content and optimum binder content. Following are the variables set for the present study: 􀂃 Fiber percentages of 0, 􀂃 Grade of bitumen:60/70 and 80/100 The dimension

20、s of the glass fiber used are as follows; 􀂃 Glass fiber length: 12.5mm 􀂃 Diameter of glass fiber: 5-10 m It is important to characterize the various pavement materials and find the optimum conditions for testing. Glass fiber available in the local market is used as reinforcement fo

21、r the experimental investigation. To eliminate any possibility of errors in sampling for preparing batch mixes, a mix has been prepared that has the gradation around the mid-value of the gradation limits given in Table . Thus, one parameter of gradation of aggregate has been fixed. Marshall Stabilit

22、y and flow values have been used as parameters for the assessment of the strength of the pavement. The Marshall Stability test has been carried out at various percentages of the fibre , to arrive at the optimum percentage of the glass fiber that gives maximum stability and a flow within specificatio

23、n limits.5. RESULTS AND DISCUSSION For various binder contents, the values of stability, flow, unit weight, percentage voids and percentage aggregate voids were examined for the reinforced and un-reinforced bitumen. For the unreinforced case, the Marshall Stability values for different bitumen conte

24、nts is as shown in Figure 1 The Marshall stability value increases with the bitumen content until it reaches a peak value corresponding to % for 60/70 grade bitumen and % for 80/100 grade bitumen. The variation of bulk density and percentage air voids with the bitumen content was also examined. The

25、bulk density vs. bitumen content variation is plotted in Figure 2. The percentage air voids vs. bitumen content variation is as shown in Figure 3. From Figure 1, Figure 2 and Figure 3, the optimum bitumen content for 60/70 grade bitumen is found to be % and that for 80/100 bitumen is found to be %.

26、Figure 4 and Figure 5 show the variation of bulk density with fibre content for 60/70 and 80/100 grade bitumen respectively. At a fibre content of %, the optimum bitumen content for reinforced mix is %.For higher grades of bitumen, the stability decreases because of insufficient bondage between aggr

27、egates , fibre and bitumen. The flow was found to be within the limits of 2 - 4 mm as specified by MORT&H 2001 (Specifications for Road and Bridge Works)There is a negligble change in unit weight.6. CONCLUSIONS Based on the experimental investigation on glass fiber reinforced bituminous mix, the fol

28、lowing conclusions were drawn: About 20 to 32 percent increase in stability values can be achieved by reinforcing the bituminous mix with glass fiber. Higher stability values indicate that the reinforced mixes would be less susceptible to cracking of Flexible pavements. From the Marshall Stability t

29、ests conducted, an optimum fiber content of % by the weight of total mix was found for a bitumen content of %. For the optimum fiber content, the maximum stability value was found to be kN for a bitumen content of %. The service life of the pavement is expected to increase after reinforcing the bitu

30、minous mix with glass fiber. From the observed improvements in stability and engineering properties, it can be concluded that the reinforced bituminous mixes are suitable in heavy traffic conditions also.7. REFERENCES1. Freeman, ., Burati Jr., ., Amirkhanian, ., and Bridges Jr., . (1989). “Polyester

31、 fibre in asphalt paving mixtures,” Proceedings, Association of Asphalt Paving Technologists, Vol. 58 pp 387-409.2. . and Singh. , (1987). “Laboratory study on flexural fatiguecharacteristics of reinforced bituminous surfacings,” Highway Research Bulletin, No. 32, pp 45- 56.3. Khanna, ., and Justo,

32、(1992). “Highway Material Testing,” Nem Chand & Bros.Roorkee, India.4. Khanna, ., and Justo, (1992). “Highway Engineering,” Nem Chand & Bros., Roorkee, India.5. Kim, ., Doh, ., and Lim, S. (1999). “Mode I reflection cracking resistance of strengthened asphalt concretes,” Construction and Building Materials, Vol. 13, pp. 243-251.6. Komatsu, T., Kikuta, H., Tuji, Y., and Muramatsu, E. (1998). “Durability assessment of geogridreinforced asphalt concrete,” Geo-textiles and Geo-membranes, Vol. 16, pp 257-271.7. Lytton, . (1989). “Use of geo-textiles for reinfo