Highway Research Record

VI. RESEARCH WORK DONE IN ACADEMIC INSTITUTIONS RELATED TO THESIS WORK
B. PAVEMENT ENGINEERING AND PAVING MATERIALS
Studies on Fibre Reinforced Bituminous Mixes

Date of Start:July 2004 to December 2004
National Institute of Technology, Tiruchirappalli (R, S)

Scope and Objective
(i) To study the strength characteristics of bituminous layer of flexible pavement by using glass fibre as reinforcement.
(ii) To study the strength variations by varying the percentage of fibres.
(iii) To arrive at optimum bitumen content and optimum fibre content of the bituminous mix by varying the percentage of       glass fibre.

Methodology
(i) Gradation of Semi Dense Bituminous Concrete has been selected for the surface layer of the flexible pavement in this study (ii) Determination of the engineering properties of Aggregates and Bitumen.
(iii) Marshall Stability method of mix design was carried out on unreinforced and glass fibre reinforced bituminous mixes to arrive     at optimum bitumen and fibre content
(iv) Analysis of mix properties by varying the % of fibre content from 0% to 0.5%
(v) Fibres are used in different grades of bitumen (60/70 & 80/100)

Findings and Conclusions

(i) About 20 to 32 percent increase in stability values can be achieved by reinforcing the bituminous mix with glass fibre. Higher     stability values indicate that the reinforced mixes would be less susceptible to cracking of flexible pavements.
(ii) From the Marshall Stability tests conducted, an optimum fibre content of 0.3% by the weight of total mix was found for     bitumen content of 4.5%.
(iii) For the optimum fibre content, the maximum stability value was found to be 17.65 kN for a bitumen content of 4.5%.
(iv) The service life of the pavement is expected to increase after reinforcing the bituminous mix with glass fibre.