Rigid Pavement Design IRC:58-2015 · plain jointed concrete pavements · cumulative fatigue damage

IRC 58 example check

PQC 300 mm · CFD 0.535 · k = 283.6 MPa/m · MR = 4.95 MPa · IRC:58-2015

Safe - CFD ≤ 1 Edit design

1. Design basis and input data

Plain jointed rigid pavement designed to IRC:58-2015 (Guidelines for the Design of Plain Jointed Rigid Pavements for Highways, 4th revision). The slab thickness is the least thickness for which the sum of the cumulative fatigue damage due to bottom-up cracking (day-time traffic with positive temperature differential) and top-down cracking (night-time traffic with negative temperature differential) does not exceed 1.0 (Cl. 6.3.4). Flexural stresses are from the regression equations of Appendix V and fatigue lives from the PCA equations 5 and 6.

Project-
Client-
Location / chainage-
RoadFour-lane / multi-lane divided highway, 2 lane(s) x 3.5 m
Edge supportTied concrete shoulder
Transverse jointscontraction joints @ 4.5 m, doweled
Design period30 years
ConcreteM40; 28-day flexural strength 4.50 MPa; E = 30,000 MPa; mu = 0.15; unit weight 24 kN/m3
Climatic zone (Table 1)Zone III - Bihar, Jharkhand, West Bengal, Assam, Eastern Odisha (excluding hilly and coastal areas)
SubbaseDry lean concrete (DLC) over granular drainage / separation layer
TYPICAL CROSS SECTION (SCHEMATIC) Pavement quality concrete M40, 300 mm (MR 4.95 MPa) on de-bonding layer (polythene 125 micron) 300 Dry lean concrete 150 mm (7 MPa at 7 days) 150 Drainage / separation layer 150 mm 150 Subgrade 500 mm, k = 50 MPa/m 3.5 m lane 3.5 m lane 1.5 m shoulder Layer thicknesses not to scale (vertical exaggeration). Longitudinal joints with tie bars shown dashed.
Fig. 1 Pavement composition (schematic)

2. Foundation - effective modulus of subgrade reaction

Effective k of the foundation (Cl. 5.7, Tables 2 to 4)OK
ReferenceDescriptionCalculationResult
Cl. 5.7.3k of subgrade (plate load test, 750 mm plate)given 50.0 MPa/m
Table 4Effective k with 150 mm DLC (granular layer below ignored)k100 = 228.0, k150 = 283.6 -> interpolated 283.6 MPa/m
Cl. 5.7.4.4Effective k for design 283.6 MPa/m
Table 2 of IRC:58-2015 - k-value from soaked CBR
Soaked CBR (%)2345710152050100
k (MPa/m)2128354248556269140220

3. Concrete strength and temperature differential

Concrete, temperature and slab stiffnessOK
ReferenceDescriptionCalculationResult
Cl. 5.8.128-day flexural strengthgiven 4.50 MPa OK
Cl. 5.8.2Design flexural strength (modulus of rupture)4.50 x 1.1 (90-day) 4.95 MPa
Cl. 5.6, Table 1Maximum positive temperature differential (day)zone III, slab 290 mm (next tabulated thickness) 16.8 deg C
Cl. 5.6.2.3Negative differential for top-down cracking (night)16.8 / 2 + 5 (built-in curl) 13.4 deg C
App. VRadius of relative stiffness l = [E h^3 / 12 k (1 - mu^2)]^0.25[30,000 x 0.290^3 / (12 x 283.6 x (1 - 0.15^2))]^0.25 0.6848 m
Table 1 - recommended maximum temperature differentials (deg C)
ZoneStates / regions150 mm200 mm250 mm300 - 400 mm
IHilly regions of Uttarakhand, West Bengal, J&K, Himachal Pradesh, Arunachal Pradesh12.513.114.315.8
IIPunjab, U.P., Uttarakhand, Gujarat, Rajasthan, Haryana, North M.P. (excluding hilly regions)12.513.114.315.8
IIIBihar, Jharkhand, West Bengal, Assam, Eastern Odisha (excluding hilly and coastal areas)15.616.416.616.8
IVMaharashtra, Karnataka, South M.P., Chhattisgarh, Andhra Pradesh, Western Odisha, North Tamil Nadu17.31920.321
VKerala and South Tamil Nadu (excluding hilly and coastal areas)1516.417.618.1
VICoastal areas bounded by hills14.615.816.217
VIICoastal areas unbounded by hills15.5171919.2

4. Design traffic and axle load repetitions

Design axle load repetitions (Cl. 5.5 and 6.3.3)OK
ReferenceDescriptionCalculationResult
Cl. 5.5.2.7Initial CVPD at opening A = P (1 + r)^x6,000 x (1 + 0.075)^0 6,000 CVPD
Eq. 1Cumulative commercial vehicles C = 365 A [(1 + r)^n - 1] / r365 x 6,000 x 103.399 226,444,692
Cl. 5.5.2.6Total axle repetitions226,444,692 x 2.35 axles / CV 532,145,025
Cl. 5.5.2.3Design lane axle repetitionsx 50 % predominant direction x 25 % (lateral placement) 66,518,128
Cl. 6.3.3Night (12 h) / day (12 h) axle repetitions60 % / 40 % 39,910,877 / 26,607,251
Cl. 6.3.3Six-hour day-time repetitions - bottom-up cracking26,607,251 / 2 13,303,626
Cl. 5.5.2.4Six-hour night-time repetitions - top-down cracking39,910,877 / 2 x 55 % (wheel base < joint spacing) 10,975,491
Category-wise axle repetitions for fatigue analysis
Axle categoryProportion %Bottom-up cracking (6 h day)Top-down cracking (6 h night)
Front (steering) single455,986,6324,938,971
Rear single151,995,5441,646,324
Tandem253,325,9062,743,873
Tridem151,995,5441,646,324
REAR SINGLE AXLES (15 % of axles) 75 100 125 150 175 200 0 5 10 15 20 Axle load (kN) Frequency % TANDEM AXLES (25 % of axles) 200 250 300 350 400 0 10 20 30 Axle load (kN) Frequency % TRIDEM AXLES (15 % of axles) 200 300 400 500 0 5 10 15 20 Axle load (kN) Frequency %
Fig. 2 Axle load spectrum (frequency of each load class)

5. Bottom-up cracking (BUC) fatigue analysis

Flexural stress at the bottom of the slab at the longitudinal edge, mid-panel, for the day-time positive temperature differential dT = 16.8 deg C, k = 283.6 MPa/m, h = 290 mm, l = 0.6848 m. S = a + b (gamma h^2 / k l^2) + c (P h / k l^4) + d dT with the coefficients for pavements with tied concrete shoulders. Load at the mid-point of each class. Front axles cause negligible bottom-up damage and are not analysed (Cl. 5.5.2.6).

Bottom-up cracking - rear single axles (Eq. V.3), expected repetitions 1,995,544
Load class (kN)P (kN)Expected reps niStress S (MPa)SR = S / MRAllowable reps NiDamage ni / Ni
185 - 195190362,1912.3990.4851,760,7100.2057
175 - 185180347,8232.3240.4705,423,7060.0641
165 - 175170364,5862.2490.45430,580,8490.0119
155 - 165160259,0222.1740.439unlimited0.0000
145 - 15515059,4672.0980.424unlimited0.0000
135 - 14514032,3282.0230.409unlimited0.0000
125 - 13513052,2831.9480.393unlimited0.0000
115 - 12512052,8821.8720.378unlimited0.0000
105 - 11511052,8821.7970.363unlimited0.0000
95 - 10510064,8551.7220.348unlimited0.0000
85 - 959064,8551.6460.333unlimited0.0000
75 - 8580282,3691.5710.317unlimited0.0000
Total1,995,5440.2818
Bottom-up cracking - tandem axles (Eq. V.9), expected repetitions 3,325,906
Load class (kN)P (kN)Expected reps niStress S (MPa)SR = S / MRAllowable reps NiDamage ni / Ni
380 - 400390482,2562.0230.409unlimited0.0000
360 - 380370349,2201.9550.395unlimited0.0000
340 - 360350120,7301.8870.381unlimited0.0000
320 - 34033083,1481.8190.367unlimited0.0000
300 - 32031089,4671.7510.354unlimited0.0000
280 - 30029041,9061.6830.340unlimited0.0000
260 - 280270129,7101.6150.326unlimited0.0000
240 - 260250172,6151.5470.313unlimited0.0000
220 - 240230209,5321.4800.299unlimited0.0000
200 - 220210212,8581.4120.285unlimited0.0000
180 - 200190296,0061.3440.271unlimited0.0000
160 - 1801701,138,4581.2760.258unlimited0.0000
Total3,325,9060.0000

6. Top-down cracking (TDC) fatigue analysis

Flexural stress at the top of the slab with the front axle near one transverse joint and one rear axle near the next joint of the same panel, night-time negative differential 13.4 deg C (Eq. V.13): S = -0.219 + 1.686 beta P h / k l^4 + 168.48 h^2 / k l^2 + 0.1089 dT with beta = 0.66 (doweled transverse joints). P = 100 % of a rear single axle, 50 % of a tandem and 33 % of a tridem axle unit.

Top-down cracking - rear single axles, expected repetitions 1,646,324
Load class (kN)P on panel (kN)Expected reps niStress S (MPa)SRAllowable reps NiDamage ni / Ni
185 - 195190.0298,8082.3300.4714,914,9060.0608
175 - 185180.0286,9542.2780.46013,988,6410.0205
165 - 175170.0300,7832.2260.450unlimited0.0000
155 - 165160.0213,6932.1750.439unlimited0.0000
145 - 155150.049,0602.1230.429unlimited0.0000
135 - 145140.026,6702.0710.418unlimited0.0000
125 - 135130.043,1342.0190.408unlimited0.0000
115 - 125120.043,6281.9680.397unlimited0.0000
105 - 115110.043,6281.9160.387unlimited0.0000
95 - 105100.053,5061.8640.377unlimited0.0000
85 - 9590.053,5061.8120.366unlimited0.0000
75 - 8580.0232,9551.7610.356unlimited0.0000
Total1,646,3240.0813
Top-down cracking - tandem axles, expected repetitions 2,743,873
Load class (kN)P on panel (kN)Expected reps niStress S (MPa)SRAllowable reps NiDamage ni / Ni
380 - 400195.0397,8622.3560.4763,231,1230.1231
360 - 380185.0288,1072.3040.4657,953,3180.0362
340 - 360175.099,6032.2520.45527,695,6050.0036
320 - 340165.068,5972.2000.445unlimited0.0000
300 - 320155.073,8102.1490.434unlimited0.0000
280 - 300145.034,5732.0970.424unlimited0.0000
260 - 280135.0107,0112.0450.413unlimited0.0000
240 - 260125.0142,4071.9930.403unlimited0.0000
220 - 240115.0172,8641.9420.392unlimited0.0000
200 - 220105.0175,6081.8900.382unlimited0.0000
180 - 20095.0244,2051.8380.371unlimited0.0000
160 - 18085.0939,2281.7870.361unlimited0.0000
Total2,743,8730.1630
Top-down cracking - tridem axles, expected repetitions 1,646,324
Load class (kN)P on panel (kN)Expected reps niStress S (MPa)SRAllowable reps NiDamage ni / Ni
530 - 560181.786,1032.2870.46211,461,4340.0075
500 - 530171.779,8472.2350.45148,016,2590.0017
470 - 500161.756,6342.1830.441unlimited0.0000
440 - 470151.7117,2182.1310.431unlimited0.0000
410 - 440141.7166,4432.0800.420unlimited0.0000
380 - 410131.7197,7232.0280.410unlimited0.0000
350 - 380121.7256,3331.9760.399unlimited0.0000
320 - 350111.7218,6321.9250.389unlimited0.0000
290 - 320101.774,9081.8730.378unlimited0.0000
260 - 29091.752,0241.8210.368unlimited0.0000
230 - 26081.751,0361.7690.357unlimited0.0000
200 - 23071.7289,4241.7180.347unlimited0.0000
Total1,646,3240.0092
CRITICAL LOAD POSITIONS (IRC:58-2015 FIGS. 3 TO 6) BOTTOM-UP CRACKING - DAY (+ dT) SCALE 1:150 max. tensile stress at bottom, edge slab curled convex (top warmer) TOP-DOWN CRACKING - NIGHT (- dT) SCALE 1:75 front axle rear axle max. tensile stress at top panel length = joint spacing 4.5 m
Fig. 3 Critical load positions for bottom-up and top-down cracking

7. Cumulative fatigue damage and slab thickness

Cumulative fatigue damage for h = 290 mmOK
ReferenceDescriptionCalculationResult
Eq. 7CFD bottom-up cracking0.282 (single) + 0.000 (tandem) 0.282
Eq. 8CFD top-down cracking0.081 + 0.163 + 0.009 0.253
Cl. 6.3.4.1CFD(BUC) + CFD(TDC) <= 10.282 + 0.253 0.535 OK
Cl. 6.3.4.1Add 10 mm for two retexturings / grinding290 + 10 300 mm
Adopt PQC thickness 300 mm (design thickness 290 mm, total CFD 0.535).
CUMULATIVE FATIGUE DAMAGE vs SLAB THICKNESS 200 250 300 350 400 0.001 0.01 0.1 1 10 100 1,000 10,000 Slab thickness h (mm) Cumulative fatigue damage CFD = 1.0 (limit) design 290 mm CFD bottom-up (BUC) CFD top-down (TDC) Total CFD
Fig. 4 Cumulative fatigue damage for the trial thicknesses (log scale)
Trial thicknesses (as Table VII.4 of IRC:58-2015)
h (mm)dT dayBUC singleBUC tandemTDC singleTDC tandemTDC tridemTotal CFDResult
20016.44616.417327.450182.603258.07137.0595421.601NOT OK
21016.61074.25083.84869.96994.49615.2621337.825NOT OK
22016.6289.92024.47428.96737.5296.536387.425NOT OK
23016.692.8078.22813.38016.7282.965134.108NOT OK
24016.634.2122.7766.6138.1661.37353.140NOT OK
25016.614.0530.7293.2704.1760.61222.841NOT OK
26016.86.4930.1361.6752.2490.28610.839NOT OK
27016.82.7060.0000.7241.0540.1094.593NOT OK
28016.80.9770.0000.2750.4470.0361.734NOT OK
29016.80.2820.0000.0810.1630.0090.535OK
30016.80.0560.0000.0160.0460.0000.118OK
31016.80.0000.0000.0000.0080.0000.008OK
32016.80.0000.0000.0000.0000.0000.000OK
33016.80.0000.0000.0000.0000.0000.000OK
34016.80.0000.0000.0000.0000.0000.000OK
35016.80.0000.0000.0000.0000.0000.000OK
36016.80.0000.0000.0000.0000.0000.000OK
37016.80.0000.0000.0000.0000.0000.000OK
38016.80.0000.0000.0000.0000.0000.000OK
39016.80.0000.0000.0000.0000.0000.000OK
40016.80.0000.0000.0000.0000.0000.000OK
FATIGUE DAMAGE BY AXLE CATEGORY (h = 290 mm) BUC - rear single 0.282 BUC - tandem 0.000 TDC - rear single 0.081 TDC - tandem 0.163 TDC - tridem 0.009 TOTAL 0.535 1.0
Fig. 5 Fatigue damage by axle category at the design thickness
STRESS RATIO vs AXLE LOAD (h = 290 mm) 0 100 200 300 400 500 0.3 0.4 0.5 0.6 Axle load of the axle unit (kN) Stress ratio SR = S / MR SR 0.45: unlimited repetitions BUC single BUC tandem TDC single TDC tandem TDC tridem
Fig. 6 Stress ratio against axle load at the design thickness
FATIGUE CURVE (PCA) - ALLOWABLE REPETITIONS 2 4 6 8 10 12 0.4 0.5 0.6 0.7 0.8 0.9 log10 N (allowable repetitions) Stress ratio endurance limit 0.45 0.55 PCA fatigue equations 5 and 6
Fig. 7 PCA fatigue relationship with the design load classes

8. Joints, dowel bars and tie bars

Contraction joints at 4.5 m (Cl. 7.1.3, not more than 4.5 m to prevent top-down cracking), sawn to 1/4 - 1/3 of the depth and sealed; expansion joints only next to bridges and culverts; longitudinal joints between lanes and at the tied shoulder (Cl. 7.1.6).

Dowel bars at transverse joints (Cl. 7.2, Appendix VIII)OK
ReferenceDescriptionCalculationResult
Table 5Dowel bar for the slab thicknessh = 300 mm -> row 300 mm 38 dia x 500 @ 300 mm
App. VIIIDesign wheel load (dual wheels as one)190 kN max. single axle / 2 95.0 kN
App. VIIILoad transferred by the dowel system95.0 x (1 - 30% to shoulder) x 50 % 33.25 kN
Cl. 7.2.7Dowels within l participating (linear distribution)l = 685 mm, spacing 300 mm: 1.000 + 0.562 + 0.124 1.686 Pt
Cl. 7.2.7Load on the outermost dowel Pt33.25 / 1.686 19.72 kN
Eq. 14Relative stiffness beta = [kmds bd / (4 E I)]^0.25I = pi x 38^4 / 64 = 102,354 mm4; kmds = 415,000 MPa/m 0.0209 /mm
Eq. 14Max. bearing stress, contraction joint z = 5 mmPt kmds (2 + beta z) / (4 beta^3 E I) 22.89 MPa OK
Eq. 14Max. bearing stress, expansion joint z = 20 mm 26.30 MPa OK
Eq. 15Allowable bearing stress Fb = (101.6 - bd) fck / 95.25(101.6 - 38) x 40 / 95.25 26.71 MPa
Tie bars at longitudinal joints (Cl. 8, Appendix IX)OK
ReferenceDescriptionCalculationResult
Eq. 16Steel per m of joint As = b f W / Sst3.5 x 1.5 x 7.20 x 1000 / 200 189.0 mm2/m
Cl. 8.2Spacing of 12 mm deformed bars113.1 / 189.0 x 1000 = 598.4 590 mm c/c OK
Eq. 17Bond length L = 2 Sst A / (B P)2 x 200 x 113.1 / (2.46 x 37.7) 487.8 mm
App. IXLength incl. 100 mm (paint) + 50 mm (placement)487.8 + 150 640 mm
Table 6Recommended minimum length for the slab thickness12 mm deformed 640 mm
-Adopted tie bar 12 mm x 640 @ 590 c/c
SLAB LAYOUT - JOINTS, DOWEL AND TIE BARS (PLAN) SCALE 1:125 TIED CONCRETE SHOULDER LANE 1 LANE 2 traffic 4500 4500 4500 3500 150 300 Dowel 38 dia x 500 @ 300 c/c Tie bar 12 dia deformed x 640 @ 590 c/c
Fig. 8 Slab layout with joints, dowel bars and tie bars
CONTRACTION JOINT WITH DOWEL BAR SCALE 1:20 300 150 500 saw cut 75 deep + sealant Dowel 38 dia x 500 mm, half length de-bonded DLC LONGITUDINAL JOINT WITH TIE BAR SCALE 1:20 300 150 640 saw cut 100 deep + sealant Tie bar 12 dia deformed x 640 mm DLC
Fig. 9 Joint details

9. Design summary and recommendations

Pavement quality concrete M40, flexural strength 4.50 MPa (28 days): 300 mm thick.
Foundation: dry lean concrete (dlc) over granular drainage / separation layer 150 mm, effective k = 284 MPa/m.
Contraction joints @ 4.5 m with 38 mm dowels x 500 mm @ 300 mm c/c; tie bars 12 mm x 640 mm @ 590 mm c/c.
Provide a drainage layer of permeability >= 300 m/day below the DLC where rainfall exceeds 1000 mm (Cl. 6.5) and a 125 micron polythene de-bonding layer between DLC and PQC (Cl. 5.7.5).

Report generated 31 Oct 2026. The bonded PQC-on-DLC option (Cl. 6.7) is not covered by this program.

10. Pavement drawing

Cross section, slab layout with joints, dowel and tie bars, joint details, CFD chart and design summary on one A3 sheet.

TYPICAL CROSS SECTION (SCHEMATIC) Pavement quality concrete M40, 300 mm (MR 4.95 MPa) on de-bonding layer (polythene 125 micron) 300 Dry lean concrete 150 mm (7 MPa at 7 days) 150 Drainage / separation layer 150 mm 150 Subgrade 500 mm, k = 50 MPa/m 3.5 m lane 3.5 m lane 1.5 m shoulder Layer thicknesses not to scale (vertical exaggeration). Longitudinal joints with tie bars shown dashed. SLAB LAYOUT - JOINTS, DOWEL AND TIE BARS (PLAN) SCALE 1:125 TIED CONCRETE SHOULDER LANE 1 LANE 2 traffic 4500 4500 4500 3500 150 300 Dowel 38 dia x 500 @ 300 c/c Tie bar 12 dia deformed x 640 @ 590 c/c CONTRACTION JOINT WITH DOWEL BAR SCALE 1:10 300 150 500 saw cut 75 deep + sealant Dowel 38 dia x 500 mm, half length de-bonded DLC LONGITUDINAL JOINT WITH TIE BAR SCALE 1:10 300 150 640 saw cut 100 deep + sealant Tie bar 12 dia deformed x 640 mm DLC CFD vs SLAB THICKNESS 200 250 300 350 400 0.001 0.01 0.1 1 10 100 1,000 10,000 Slab thickness h (mm) Cumulative fatigue damage CFD = 1.0 (limit) design 290 mm CFD bottom-up (BUC) CFD top-down (TDC) Total CFD DESIGN SUMMARY (IRC:58-2015) Design thickness (CFD <= 1) 290 mm Adopted PQC thickness 300 mm (incl. 10 mm for retexturing) CFD bottom-up / top-down 0.282 / 0.253 Total CFD 0.535 <= 1.0 Effective k of foundation 283.6 MPa/m Design flexural strength 4.95 MPa (90-day) Temperature differential day / night 16.8 / 13.4 deg C Radius of relative stiffness l 685 mm Design traffic (CVs, design period) 226.44 million Axle repetitions BUC / TDC (6 h) 13.30 / 10.98 million Dowel bars 38 mm dia x 500 mm @ 300 mm c/c Tie bars 12 mm deformed x 640 mm @ 590 mm c/c Contraction joint spacing 4.5 m Result: SAFE - CFD <= 1 NOTES 1. All dimensions in mm unless noted otherwise. 2. PQC to MORTH Section 600; DLC 7 MPa at 7 days (IRC:SP:49). 3. Polythene 125 micron de-bonding layer between DLC and PQC. 4. Dowels plain MS, half length de-bonded; tie bars to IS 1786. 5. Joints sawn and sealed as per IRC:57; spacing <= 4.5 m. IRC 58 example check Rigid pavement 300 mm PQC · Designed: - Checked: - Date: 31 Oct 2026 Scale: as shown Sheet 1 of 1