RAHUL GHOSH_Ppt file civil engineer BTech

Ppt file

1. PPT PAVEMENT DESIGN CE(PE)705B Continuous Assessment 1 (CA1): COLLEGE / INSTITUTION : CAMELLIA INSTITUTE OF TECHNOLOGY & MANAGEMENT AFFILIATED BY MAKAUT NAME : RAHUL GHOSH ROLL NO : 25701322022 REGISTRATION NO : 222570120083 OF 2022-23 SEM – 7 TH DEPARTMENT : CIVIL ENGINEERING

2. DESIGN OF FLEXIBLE PAVEMENT : 2 Presented by: Rahul Ghosh

3. What is design ? 3 Design of pavement includes deciding the number of layers, its composition and thickness for selected material, to support traffic load safely without failure.

4. Various cases in design. 4 The flexible pavement with different combinations of traffic loads and material properties. 1) Granular base and Granular sub-base. 2) Cementitious base and sub-base with agg. Interlayer. 3) Cementitious base and sub-base with SAMI. 4) RAP agg. Over cemented sub-base 5) Cemented base and Granular sub-base

5. Material properties 5 CBR : The CBR values are calculated after every kilometre on selected stretch of 10 km having the same type of soil. Suppose the values obtained are: 3.8, 2.8, 4.5, 3.9, 4.2, 2.9, 4.7, 4.3, 4.0 and 4.6%. Based on the collected data the design CBR (90 th percentile CBR) is calculated as below:

6. Solution : 6 Arrange in ascending order : 2.8, 2.9, 3.8, 3.9, 4.0, 4.2, 4.3, 4.5, 4.6 and 4.7. Calculate the percentage greater than equal of the value as follows: For CBR of 3.8, percentage of values greater than equal to 3.8 = (8/10) x100 = 80% Similarly for 2.8 % is 100%, 4.5% CBR is 80% and so on. Now a plot is made between Percentages of values greater than equal to the CBR values versus the CBR as follows.

7. Continue … 7 RESULT : The 90 th Percentile CBR value is 2.90%

8. Effective CBR: 8 (Figure 5.1, Page 11, IRC: 37: 2012)

9. Poisson’s ratio 9 Poisson’s ratio µ is define as the ratio of lateral strain (ɛ l ) to the axial strain (ɛ a ), caused by load parallel to the axis along which ɛ a is measured. It is found that for most of the pavement structures, the influence of µ value is normally small. For most of cement treated materials (soil cement, cement treated base, lean concrete and PCC), the value of µ normally lies between 0.10 and 0.25 . Unbound granular material lie between 0.2 and 0.5 and those for bituminous mixes range from 0.35 to 0.50

10. Elastic modulus 10 Elastic moduli of various pavement materials are obtained either through tests or through the recommendations available in the guidelines. Repeated flexure or indirect tensile tests are carried out to determine the dynamic modulus E d of bituminous mixes.

11. Resilient modulus 11 Resilient modulus is the measure of its elastic behaviour determined from recoverable deformation in the laboratory tests. The behaviour of the subgrade is essentially elastic under the transient traffic loading with negligible permanent deformation in a single pass. This can be determined in the laboratory by conducting tests.

12. Calculation of Design factor 12 1) Design Traffic, 2) Axle load survey, 3) Vehicle Damage Factor 4) Lane Distribution Factor

13. Axle load spectrum 13 Single Axle Load Tandem Axle Load Tridem Axle Load Axle load Class (KN) Percentage of Axles Axle load Class (KN) Percentage of Axles Axle load Class (KN) Percentage of Axles 185-195 0.64 390-410 1.85 585-615 1.40 175-185 0.80 370-390 2.03 555-585 1.60 165-175 0.80 350-370 2.03 525-555 1.60 155-165 2.58 330-350 2.08 495-525 1.80 145-155 2.58 310-330 2.08 465-495 1.80 135-145 5.80 290-310 4.17 435-465 4.40 125-135 5.80 270-290 4.17 405-435 4.40 115-125 11.82 250-270 12.67 375-405 13.10 105-115 11.82 230-250 12.67 345-375 13.10 95-105 12.90 210-230 10.45 315-345 10.90 85-95 12.16 190-210 10.45 285-315 10.40 < 85 32.30 170-190 7.05 255-285 7.15 <170 28.28 <255 28.33 Total 100 100 100