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From page 166... ... 155 CHAPTER 5 - ANALYSIS RESULTS FOR THE SPS-1 EXPERIMENT 5.1 INTRODUCTION The purpose of this chapter is to provide a summary of findings from the previous studies and the results of the various analyses conducted for the SPS-1 experiment on flexible pavements in this study. The performance and structural response indicators used in the analysis include fatigue (alligator) Read the entire page →
From page 167... ... 156 5.2 PREVIOUS STUDIES This section summarizes the findings from the literature review of research reports that deal with pavement performance in the field. The review included FHWA/LTPP reports, NCHRP reports as well as additional literature, and was focused on research that has identified factors affecting pavement response and performance including roughness. Read the entire page →
From page 168... ... 157 • The HMA pavements with unbound aggregate layers have slightly more fatigue cracking and higher IRI values than those sections with asphalt-treated base layers. • The test sections with coarse-grained soils, asphalt-treated base layers, permeable base layers, thicker bases, and thicker HMA layers were found to be smoother. Read the entire page →
From page 169... ... 158 sections in TX (48) are showing higher increase in IRI of over 10% within an approximate 6-month period, which is attributed to rutting. Read the entire page →
From page 170... ... 159 5.3 EFFECT OF CONSTRUCTION ON PAVEMENT PERFORMANCE For the SPS-1 experiment, detailed construction guidelines were developed by LTPP (see Chapter 2) for the participating agencies to control variability in construction across sites. Read the entire page →
From page 171... ... 160 In order to further investigate the construction-related performance issues, each performance measure for all pavement sections in SPS-1 experiment was examined over time. This analysis helped minimize the bias, if any, in the results. Read the entire page →
From page 172... ... 161 high variation in the field air void content between these identified sites. High air voids in the pavement sections at the Kansas site KS (20) Read the entire page →
From page 173... ... 162 with treated bases. A slight (0.05 Read the entire page →
From page 174... ... 163 Table 5-1 Identified sites and sections with rutting problems Site Sections deleted due to extensive rutting Probable cause of rutting Comments Arizona, AZ (4) All 12 sections HMA and Base The rutting is either occurring due to HMA mix problems or base or both (from transverse profile) Read the entire page →
From page 175... ... 164 0 5 10 15 20 25 30 35 0 1 2 3 4 5 6 7 8 9 10 11 Age (years) Read the entire page →
From page 176... ... 165 -25 -20 -15 -10 -5 0 5 10 0 1000 2000 3000 4000 Distance from the edge (mm) Read the entire page →
From page 177... ... 166 y = 3.6226x0.27 R2 = 0.3535 0 5 10 15 20 25 30 35 0 2 4 6 8 10 12 Age (years) Read the entire page →
From page 178... ... 167 Table 5-3 Summary of p-values from ANOVA for determining the effect of main design factors on pavement rutting Rutting Type Design Factor Non-structural ruttinga Structural rutting Overall HMA thickness 0.71 0.074 0.20 Base type 0.20 0.51 0.017 Base thickness 0.99 0.08 0.195 Drainage 0.12 0.25 0.030 Site (blocked) 0.15 0.00 0.00 R 2=0.343 N=53 R2=0.55 N=159 R2=0.57 N=212 Note: a Mix-related or premature rutting in un-bound layers. Read the entire page →
From page 179... ... 168 Table 5-5 Summary of p-values from ANOVA for determining the effect of experimental factors on pavement rutting Rutting Type Experimental Factor Non-structural ruttinga Structural rutting HMA thickness 0.16 0.043 Base type 0.94 0.54 Base thickness 0.76 0.09 Drainage 0.50 0.28 Subgrade 0.46 0.43 Zone 0.27 0.00 Traffic 0.000 0.013 R 2=0.552 N=53 R2=0.55 N=159 Note: a Mix-related or premature rutting in un-bound layers. Table 5-6 Summary of marginal means from ANOVA for determining the effect of experimental factors on pavement rutting Rutting Type Design Factor Non-structural rutting Structural rutting 102 mm 9.7 5.7 HMA thickness 178 mm 11.8 5.0 DGAB 10.7 5.4 ATB 10.7 5.2 Base type ATB/DGAB 10.7 5.3 203 mm 9.7 5.7 305 mm 10.7 5.0 Base thickness 406 mm 10.7 5.2 N 11.8 5.5 Drainage Y 10.7 5.1 F 13 5.2 Subgrade C 9.7 5.4 WF 6.5 4.9 WNF 13 5.6 DF 14.4 4.0 Zone DNF - 7.1 MSEa 0.137 0.091 Note: a MSE is in natural log. Read the entire page →
From page 180... ... 169 Fatigue Cracking It was observed that sections from the Kansas, KS (20) , site exhibited the highest area of cracking at an early age compared to sections from other sites. Read the entire page →
From page 181... ... 170 0 50 100 150 200 250 300 350 400 0 1 2 3 4 5 6 7 8 9 10 11 Age (years) Read the entire page →
From page 182... ... 171 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 1 2 3 4 5 6 7 8 9 10 11 Age (years) Read the entire page →
From page 183... ... 172 0 50 100 150 200 250 300 0 1 2 3 4 5 6 7 8 9 10 11 Age (years) Read the entire page →
From page 184... ... 173 All the drained sections of the SPS-1 experiment were video taped to assess the condition of the drainage in the project 1-34C [4] Read the entire page →
From page 185... ... 174 Table 5-7 Subjective ratings of drainage functioning at SPS-1 test sections based on video inspection results (source: [4] Read the entire page →
From page 186... ... 175 5.4 SPS-1 PROJECT PERFORMANCE SUMMARIES This section is a summary of the performance trends for each site within the SPS-1 experiment based on the latest year data. The performance summary for each site is based on the data available in the Release 17.0 of the DataPave. Read the entire page →
From page 187... ... 176 cracking of length 76 m and 45 m occurred on sections 113 and 121, while other sections have less than 30 m of transverse cracking. Rutting of 14 mm and 25 mm occurred on sections 114 and 119, respectively, after 6 years. Read the entire page →
From page 188... ... 177 Iowa, IA (19) The performance data is available for 9 years (1995-2003) Read the entire page →
From page 189... ... 178 Michigan, MI (26) The performance data is available for 7 years (1996-2003) Read the entire page →
From page 190... ... 179 Nevada, NV (32) The performance data was collected for 8 years (1996-2003) Read the entire page →
From page 191... ... 180 of construction. All sections have IRI greater than 1.4 m/km, while sections 103 and 108 have IRI of 3 and 2 m/km, respectively. Read the entire page →
From page 192... ... 181 Wisconsin, WI (55) The performance data was collected for only 4 years (1998-2002) Read the entire page →
From page 193... ... 182 Figure 5-15 Methodology for site level analysis (SPS-1) Site Level Analysis Level-A Comparisons Level-B Comparisons Effect of HMA Thickness 4" vs. Read the entire page →
From page 194... ... 183 Each analysis was conducted separately for each performance measure. The pavement performance measures considered include: • Fatigue cracking • Rutting • Roughness (IRI) Read the entire page →
From page 195... ... 184 5.5.1 Effects of design features on performance – Paired Comparisons at Level-A A summary of p-values obtained from the non-parametric tests on RPIs (for all 18 sites) from level-A analyses is in Table 5-8. Read the entire page →
From page 196... ... 185 • Roughness (IRI) : The effect of HMA thickness on IRI is consistent across sites. Read the entire page →
From page 197... ... 186 • Roughness (IRI) : The effect of base type on IRI is consistent across sites. Read the entire page →
From page 198... ... 187 • Transverse cracking: Drainage has somewhat consistent effect on transverse cracking. Sections with drainage have performed better than those without drainage in most of the sites. Read the entire page →
From page 199... ... 188 5.5.2 Effects of design features – Paired Comparisons at Level-B As explained in Chapter 4, level-B comparisons are more "controlled" compared to levelA comparisons. To study the consistency of the effect of HMA thickness across sites, nonparametric testing was performed on relative performance corresponding to 102 mm and 178 mm HMA thicknesses, within each base type. Read the entire page →
From page 200... ... 189 results show that the difference in performance between these two base types is not statistically significant. Base Thickness The effect of base thickness can be better seen when using Level-B comparisons, mainly because it is a more secondary effect relative to HMA layer thickness and base type (treated versus untreated) Read the entire page →
From page 201... ... 190 5.6 OVERALL ANALYSIS The results obtained from statistical analyses performed on the SPS-1 data are presented in this section. Both the performance and response variables were analyzed to study the effects of various design and site-factors on the pavement sections. Read the entire page →
From page 202... ... 191 c) Base Thickness: The effect of base thickness on fatigue cracking was found to be insignificant. Read the entire page →
From page 203... ... 192 e) Climate: The effect of climate (within wet regions) Read the entire page →
From page 204... ... 193 Transverse cracking: Figure 5-19 indicates that about 40% of all test sections have shown some transverse cracking, with about 10% of all test sections showing 20m or higher length of transverse cracking. The effects of specific design and site factors are discussed below. Read the entire page →
From page 205... ... 194 e) Climatic Zone: The effect of climatic zone (within wet regions) Read the entire page →
From page 206... ... 195 0% 20% 40% 60% 80% 100% 0% 5% 10% 15% 20% 25% % Fatigue Cracking P e r e c e n t o f t e s t s e c t i o n s 4 7 (a) HMA thickness 0% 20% 40% 60% 80% 100% 0% 5% 10% 15% 20% 25% % Fatigue Cracking P e r c e n t o f t e s t s e c t i o n s DGAB ATB ATB+DGAB (b) Read the entire page →
From page 207... ... 196 0% 20% 40% 60% 80% 100% 0 2.5 5 7.5 10 12.5 15 Rut Depth (mm) Read the entire page →
From page 208... ... 197 0% 20% 40% 60% 80% 100% 0.6 0.8 1 1.2 1.4 1.6 1.8 2 IRI (m/km) Read the entire page →
From page 209... ... 198 0% 20% 40% 60% 80% 100% 0 5 10 15 20 25 Transverse Cracking (m) Read the entire page →
From page 210... ... 199 0% 20% 40% 60% 80% 100% 0 50 100 150 200 250 Longitudinal Cracking-WP (m) Read the entire page →
From page 211... ... 200 0% 20% 40% 60% 80% 100% 0 50 100 150 200 250 Longitudinal Cracking-NWP (m) Read the entire page →
From page 212... ... 201 5.6.2 Frequency-based methods Two frequency-based methods were used- Linear Discriminant Analysis and Binary Logistic Regression (details in Chapter 4) Read the entire page →
From page 213... ... 202 • Transverse cracking: The effect of base type to a lesser degree was found to discriminate between cracked and non-cracked sections. Test sections in wet freeze zone with unbound (DGAB) Read the entire page →
From page 214... ... 203 Logistic Regression The binary logistic regression model was used to model the probability of occurrence for the various performance measures. This method requires fewer assumptions than discriminant analysis and even when the assumptions required for discriminant analysis are not satisfied, it performs well. Read the entire page →
From page 215... ... 204 Table 5-11 Summary of p-values from BLR for determining the effect of experimental factors on pavement performance measures (Wet zones) Performance Measures Longitudinal cracking Design Factor Fatigue cracking Rutting Roughness Transverse cracking WP NWP HMA thickness 0.160 (1.8) Read the entire page →
From page 216... ... 205 • Roughness: HMA Thickness -- Thin (102 mm) pavement sections have a higher probability of showing higher roughness (IRI > 1.4 m/km) Read the entire page →
From page 217... ... 206 5.6.3 Analysis of Variance Several analyses of variance (ANOVA) were conducted for each of the performance measures and response indicators. Read the entire page →
From page 218... ... 207 a normal probability distribution, where ln (X) is the natural logarithm to the base e. Read the entire page →
From page 219... ... 208 sections with thinner base [203 mm (8-inch) Read the entire page →
From page 220... ... 209 Table 5-13 Summary of p-values from ANOVA for determining the effect of main design factors on pavement performance measures -- Overall Performance Measures IRI Longitudinal cracking Design Factor Fatigue cracking Rut1 depth ∆IRI IRIo Transverse cracking WP NWP HMA Thickness 0.163 0.074 0.870 0.006 0.758 0.737 0.787 Base Type 0.000* 0.510 0.004 0.000 0.016 0.079 0.031 Base Thickness 0.951 0.080 0.027 0.028 0.697 0.488 0.008* Read the entire page →
From page 221... ... 210 The ANOVA was conducted for the design factors within each climatic zone as per the project panel recommendations. However, this analysis suffers from the lack of data within zones, especially within "Dry" zones, where only 2 sites each are available for DF and DNF zones. Read the entire page →
From page 222... ... 211 Table 5-15 Summary of p-values from ANOVA for determining the effect of design factors on flexible pavement performance -- WF Zone Performance Measures IRI Longitudinal cracking Design Factor Fatigue cracking Rut Depth ∆IRI IRIo Transverse cracking WP NWP HMA thickness 0.745 0.688 0.277 0.133 0.560 0.893 0.762 Base type 0.004* Read the entire page →
From page 223... ... 212 The following discussion summarizes the effect of key design factors on performance in WNF climatic zone (see Table 5-17 and Table 5-18) : • Effect of base type: The effect of base type was found to be significant only for the change in roughness. Read the entire page →
From page 224... ... 213 Table 5-17 Summary of p-values from ANOVA for determining the effect of design factors on flexible pavement performance -- WNF Zone Performance Measures IRI Longitudinal cracking Design Factor Fatigue cracking Rut Depth ∆IRI IRIo Transverse cracking WP NWP HMA thickness 0.077* 0.576 0.948 0.141 0.383 0.759 0.532 Base type 0.545 0.547 0.065* Read the entire page →
From page 225... ... 214 5.6.3.2 Effect of Site Factors on Pavement Performance The third ANOVA was targeted at determining the significance of subgrade type and climatic zone. Traffic, age and variability in target layer thicknesses were considered as covariates. Read the entire page →
From page 226... ... 215 Table 5-19 Summary of p-values from ANOVA for determining the effect of site factors on pavement performance measures (Main effects only) Performance Measures IRI Longitudinal cracking Site Factor Fatigue cracking Rut Depth ∆IRI IRIo Transverse cracking WP NWP Subgrade type 0.680 0.432 0.000* Read the entire page →
From page 227... ... 216 Table 5-21 Summary of p-values from ANOVA for determining the effect of site factors on pavement performance measures (With interaction effects) Performance Measures IRI Longitudinal cracking Site Factor Fatigue cracking Rut Depth ∆IRI IRIo Transverse cracking WP NWP Subgrade type 0.626 0.886 0.018 0.653 0.247 0.480 0.191 Climatic Zone 0.049 0.007* Read the entire page →
From page 228... ... 217 In case of significant interaction between site factors, the interpretation of results are based on the comparison of cell means, i.e., the mean performance of sections corresponding to each subgrade type should be compared within each climatic zone. The following discussion summarizes the effect of climatic zone and subgrade type on the key performance measures: • Fatigue cracking: More fatigue cracking was observed on sections located in "wet" climates. Read the entire page →
From page 229... ... 218 compared to those located in other zones, and this effect was found to be statistically and practically significant. • Longitudinal cracking: As the interaction effect between subgrade type and climatic zone is significant for longitudinal cracking-WP, the conclusions are based on comparing cell means for sections built on each subgrade type within each climatic zone. Read the entire page →
From page 230... ... 219 • Fatigue Cracking: Climate appears to be significantly affecting fatigue performance. Pavements located in "wet" or "freeze" climate have exhibited significantly higher amount of fatigue cracking than those located in "dry" or "no-freeze" climate, respectively. Read the entire page →
From page 231... ... 220 Table 5-23 Summary of p-values from one-way ANOVA for determining the effect of site factors on pavement performance measures Performance Measures IRI Longitudinal cracking Site Factor Fatigue cracking Rut depth ∆IRI IRIo Transverse cracking WP NWP Subgrade Type Fine vs. Coarse 0.03 (+) Read the entire page →
From page 232... ... 221 5.6.3.3 Effect of Design Factors on Pavement Performance (univariate) based on standard deviate As explained before, the experiment design and the performance of the test sections have rendered the SPS-1 experiment "unbalanced". Read the entire page →
From page 233... ... 222 In the SPS-1 experiment, HMA thickness and drainage have two levels (i.e. Read the entire page →
From page 234... ... 223 cracking than those with 305 mm (12-inch) or 203 mm (8-inch) Read the entire page →
From page 236... ... 225 Table 5-25 Summary of p-values for comparisons of standard deviates -- Fatigue cracking By subgrade By climatic zone By subgrade and zone WF WNF DF DNF Design Factor Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C HMA thickness 102 mm vs. 178 mm 0.003 0.167 0.008 0.890 0.002 0.102 0.213 0.900 0.900 0.160 0.005 Overall 203 mm vs. Read the entire page →
From page 237... ... 226 Table 5-26 Summary of means of PI for fatigue cracking By subgrade and zone By subgrade By climatic zone WF WNF DF DNF Design Factors Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C 102 mm 14.6 19.2 11.8 10.7 19.8 24.3 3.4 5.5 15.2 47.0 1.6 24.3 0.2 6.5 HMA thickness 178 mm 9.4 10.3 8.7 11.2 8.4 13.0 2.3 7.4 15.5 20.3 0.6 13.0 0.0 4.5 203 mm 13.4 17.2 10.9 11.8 16.5 21.9 1.4 6.9 16.4 40.1 0.8 21.9 0.0 2.9 305 mm 11.9 14.8 9.9 12.4 13.5 14.3 3.6 8.4 16.5 31.8 1.2 14.3 0.2 7.0 Overall 406 mm 8.8 7.8 9.5 5.6 9.7 21.5 4.2 2.0 9.9 22.1 1.4 21.5 0.0 8.5 203 mm 13.4 22.3 7.5 8.7 22.1 18.0 1.1 8.3 9.1 54.4 0.6 18.0 0.0 2.2 ND 305 mm 9.8 10.5 9.4 14.0 8.1 5.9 5.9 8.3 19.6 18.7 1.0 5.9 0.4 11.5 203 mm 13.4 8.8 16.2 17.0 8.2 27.9 1.9 4.5 27.4 18.7 1.2 27.9 0.1 3.8 305 mm 14.9 21.4 10.5 10.1 21.6 26.9 0.2 8.5 11.8 51.5 1.6 26.9 0.0 0.4 Base thickness D 406 mm 8.8 7.8 9.5 5.6 9.7 21.5 4.2 2.0 9.9 22.1 1.4 21.5 0.0 8.5 DGAB 18.8 23.4 16.1 18.5 22.5 26.0 3.2 7.7 27.2 53.8 1.7 26.0 0.2 6.3 ATB 6.8 7.7 6.2 5.8 6.8 14.7 2.7 5.3 6.4 15.8 0.8 14.7 0.0 5.4 Overall ATB/DGAB 8.8 13.4 5.7 8.2 11.5 10.3 2.0 8.2 8.3 28.0 0.5 10.3 0.0 4.1 DGAB 20.6 34.3 13.0 20.0 30.6 13.9 3.8 11.3 25.9 74.3 1.4 13.9 0.5 7.2 ATB 6.4 6.0 6.7 7.7 3.2 11.5 4.7 6.9 8.9 7.3 0.4 11.5 0.1 9.3 ND ATB/DGAB 8.8 13.4 5.7 8.2 11.5 10.3 2.0 8.2 8.3 28.0 0.5 10.3 0.0 4.1 DGAB 17.7 16.9 18.1 17.6 17.1 34.0 2.8 5.9 28.0 40.1 1.8 34.0 0.0 5.7 Base type D ATB 7.2 8.9 5.9 4.3 9.1 16.8 1.4 4.0 4.7 21.4 1.0 16.8 0.0 2.8 ND 11.6 16.4 8.5 11.3 15.1 11.9 3.5 8.3 14.4 36.5 0.8 11.9 0.2 6.8 Overall D 12.3 12.7 12.0 10.6 13.1 25.4 2.1 4.8 16.3 30.7 1.4 25.4 0.0 4.2 ND 20.6 34.3 13.0 20.0 30.6 13.9 3.8 11.3 25.9 74.3 1.4 13.9 0.5 7.2 DGAB D 17.7 16.9 18.1 17.6 17.1 34.0 2.8 5.9 28.0 40.1 1.8 34.0 0.0 5.7 ND 6.4 6.0 6.7 7.7 3.2 11.5 4.7 6.9 8.9 7.3 0.4 11.5 0.1 9.3 Drainage ATB D 7.2 8.9 5.9 4.3 9.1 16.8 1.4 4.0 4.7 21.4 1.0 16.8 0.0 2.8 Read the entire page →
From page 238... ... 227 Structural Rutting The effects of the design and site factors, in terms of standard deviate, are shown in Figure 5-23. The summary of p-values corresponding to the analyses performed to study the effects of design factors on structural rutting is presented in Table 5-27. Read the entire page →
From page 239... ... 228 may be more effective in inhibiting rutting for pavements on fine-grained soils, when located in WNF zone. The interaction effects among the experimental factors, on structural rutting, are reported below: A marginal effect of drainage was observed on pavements built with ATB and on finegrained soils. Read the entire page →
From page 241... ... 230 Table 5-27 Summary of p-values for comparisons of standard deviates -- Structural rutting By subgrade By climatic zone By subgrade and zone WF WNF DF DNF Design Factor Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C HMA thickness 102 mm vs. 178 mm 0.458 0.210 0.0270 0.580 0.501 0.001 0.078 0.420 0.900 0.900 0.300 Overall 203 mm vs. Read the entire page →
From page 242... ... 231 Table 5-28 Summary of means of PI for structural rutting By subgrade and zone By subgrade By climatic zone WF WNF DF DNF Design Factors Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C 102 mm 5.4 5.7 5.1 5.2 5.8 4.7 6.3 5.3 5.1 5.9 5.7 4.7 6.3 HMA thickness 178 mm 5.2 5.8 4.6 5.4 5.5 3.3 6.7 5.7 5.1 5.7 5.1 3.3 6.7 203 mm 5.5 5.9 5.2 5.4 6.1 4.0 6.5 5.8 5.1 5.7 6.7 4.0 6.5 305 mm 5.2 5.7 4.7 5.2 5.4 3.8 6.4 5.1 5.4 6.0 4.5 3.8 6.4 Overall 406 mm 5.1 5.7 4.5 5.0 4.9 4.7 6.7 5.6 4.4 5.3 4.3 4.7 6.7 203 mm 5.9 6.3 5.5 5.7 6.8 3.9 6.5 6.3 5.3 6.2 7.5 3.9 6.5 ND 305 mm 5.1 5.5 4.6 5.2 5.4 3.2 6.4 4.2 5.9 6.2 4.2 3.2 6.4 203 mm 5.0 5.3 4.8 4.9 5.3 4.0 6.4 5.0 4.9 5.1 5.6 4.0 6.4 305 mm 5.3 6.0 4.7 5.3 5.4 4.7 6.3 6.2 4.5 5.7 5.0 4.7 6.3 Base thickness D 406 mm 5.1 5.7 4.5 5.0 4.9 4.7 6.7 5.6 4.4 5.3 4.3 4.7 6.7 DGAB 5.4 6.1 4.7 5.5 5.3 4.3 6.5 6.8 4.7 5.4 5.2 4.3 6.5 ATB 5.1 5.4 4.9 5.0 5.6 3.7 6.5 4.7 5.2 5.7 5.4 3.7 6.5 Overall ATB/DGAB 5.6 6.0 5.2 5.4 6.5 3.8 6.1 5.1 5.8 6.9 5.8 3.8 6.1 DGAB 5.3 6.0 4.9 5.2 5.9 3.5 6.5 5.6 5.1 6.0 5.8 3.5 6.5 ATB 5.4 5.7 5.1 5.6 5.8 3.3 6.8 5.3 5.9 5.7 5.8 3.3 6.8 ND ATB/DGAB 5.6 6.0 5.2 5.4 6.5 3.8 6.1 5.1 5.8 6.9 5.8 3.8 6.1 DGAB 5.4 6.2 4.6 5.7 5.0 4.9 6.6 7.1 4.4 5.1 4.7 4.9 6.6 Base type D ATB 4.9 5.2 4.7 4.5 5.4 4.1 6.3 4.2 4.8 5.6 5.2 4.1 6.3 ND 5.5 5.9 5.1 5.4 6.1 3.5 6.5 5.2 5.6 6.2 5.8 3.5 6.5 Overall D 5.1 5.7 4.7 5.1 5.2 4.5 6.5 5.7 4.6 5.4 5.0 4.5 6.5 ND 5.3 6.0 4.9 5.2 5.9 3.5 6.5 5.6 5.1 6.0 5.8 3.5 6.5 DGAB D 5.4 6.2 4.6 5.7 5.0 4.9 6.6 7.1 4.4 5.1 4.7 4.9 6.6 ND 5.4 5.7 5.1 5.6 5.8 3.3 6.8 5.3 5.9 5.7 5.8 3.3 6.8 Drainage ATB D 4.9 5.2 4.7 4.5 5.4 4.1 6.3 4.2 4.8 5.6 5.2 4.1 6.3 Read the entire page →
From page 243... ... 232 Roughness The effects of the design and site factors, in terms of standard deviate, are shown in Figure 5-24. The summary of p-values corresponding to the analyses performed to study the effects of design factors on roughness is shown in Table 5-28. Read the entire page →
From page 244... ... 233 The interaction effects among the experimental factors, on the change in roughness, are reported below: Also for un-drained pavements built on fine-grained soils, the effect of base type is significant, in that pavements with ATB have significantly lower ∆IRI. Furthermore, the effect of drainage for sections with DGAB and built on fine-grained soils, is significant. Read the entire page →
From page 245... ... 234 This page is intentionally left blank. Read the entire page →
From page 247... ... 236 Table 5-29 Summary of p-values for comparisons of standard deviates -- Change in IRI By subgrade By climatic zone By subgrade and zone WF WNF DF DNF Design Factor Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C HMA thickness 102 mm vs. 178 mm 0.047 0.008 0.800 0.540 0.220 0.038 0.660 0.140 0.400 0.160 0.670 Overall 203 mm vs. Read the entire page →
From page 248... ... 237 Table 5-30 Summary of means of PI for change in IRI By subgrade and zone By subgrade By climatic zone WF WNF DF DNF Design Factors Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C 102 mm 0.27 0.44 0.14 0.38 0.13 0.18 0.31 0.52 0.17 0.20 0.08 0.18 0.50 0.11 HMA thickness 178 mm 0.22 0.32 0.14 0.37 0.07 0.04 0.24 0.45 0.24 0.05 0.08 0.04 0.29 0.19 203 mm 0.30 0.48 0.16 0.46 0.16 0.10 0.29 0.59 0.26 0.24 0.11 0.10 0.45 0.14 305 mm 0.22 0.34 0.12 0.35 0.05 0.14 0.23 0.47 0.17 0.03 0.06 0.14 0.34 0.12 Overall 406 mm 0.18 0.25 0.11 0.23 0.06 0.08 0.33 0.28 0.15 0.08 0.05 0.08 0.41 0.24 203 mm 0.35 0.59 0.16 0.56 0.15 0.09 0.34 0.77 0.24 0.21 0.11 0.09 0.51 0.17 ND 305 mm 0.24 0.38 0.12 0.37 0.05 0.15 0.29 0.52 0.13 0.03 0.07 0.15 0.43 0.15 203 mm 0.22 0.29 0.17 0.29 0.17 0.11 0.22 0.29 0.30 0.28 0.09 0.11 0.34 0.10 305 mm 0.21 0.29 0.13 0.34 0.06 0.12 0.14 0.41 0.22 0.04 0.06 0.12 0.20 0.07 Base thickness D 406 mm 0.18 0.25 0.11 0.23 0.06 0.08 0.33 0.28 0.15 0.08 0.05 0.08 0.41 0.24 DGAB 0.31 0.49 0.16 0.47 0.14 0.19 0.27 0.63 0.24 0.24 0.07 0.19 0.41 0.12 ATB 0.18 0.27 0.11 0.28 0.06 0.05 0.27 0.34 0.18 0.05 0.06 0.05 0.38 0.15 Overall ATB/DGAB 0.26 0.38 0.15 0.39 0.10 0.07 0.30 0.51 0.19 0.04 0.14 0.07 0.39 0.21 DGAB 0.41 0.73 0.16 0.66 0.15 0.27 0.34 1.02 0.18 0.26 0.07 0.27 0.53 0.14 ATB 0.23 0.37 0.10 0.36 0.06 0.02 0.32 0.47 0.18 0.06 0.06 0.02 0.50 0.14 ND ATB/DGAB 0.26 0.38 0.15 0.39 0.10 0.07 0.30 0.51 0.19 0.04 0.14 0.07 0.39 0.21 DGAB 0.25 0.35 0.16 0.35 0.14 0.13 0.22 0.40 0.28 0.23 0.08 0.13 0.33 0.11 Base type D ATB 0.16 0.21 0.11 0.22 0.05 0.08 0.23 0.25 0.17 0.04 0.06 0.08 0.31 0.16 ND 0.30 0.48 0.14 0.46 0.10 0.12 0.32 0.64 0.19 0.12 0.09 0.12 0.47 0.16 Overall D 0.20 0.28 0.14 0.29 0.10 0.10 0.23 0.33 0.22 0.14 0.07 0.10 0.32 0.14 ND 0.41 0.73 0.16 0.66 0.15 0.27 0.34 1.02 0.18 0.26 0.07 0.27 0.53 0.14 DGAB D 0.25 0.35 0.16 0.35 0.14 0.13 0.22 0.40 0.28 0.23 0.08 0.13 0.33 0.11 ND 0.23 0.37 0.10 0.36 0.06 0.02 0.32 0.47 0.18 0.06 0.06 0.02 0.50 0.14 Drainage ATB D 0.16 0.21 0.11 0.22 0.05 0.08 0.23 0.25 0.17 0.04 0.06 0.08 0.31 0.16 Read the entire page →
From page 249... ... 238 Transverse Cracking The effects of the design and site factors, in terms of standard deviate, are shown in Figure 5-25. The summary of p-values corresponding to the analyses performed to study the effects of design factors on transverse cracking is presented in Table 5-31. Read the entire page →
From page 251... ... 240 Table 5-31 Summary of p-values for comparisons of standard deviates -- Transverse cracking By subgrade By climatic zone By subgrade and zone WF WNF DF DNF Design Factor Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C HMA thickness 102 mm vs. 178 mm 0.100 0.170 0.330 0.610 0.310 0.310 0.097 0.850 0.630 0.180 0.940 Overall 203 mm vs. Read the entire page →
From page 252... ... 241 Table 5-32 Summary of means of PI for transverse cracking By subgrade and zone By subgrade By climatic zone WF WNF DF DNF Design Factors Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C 102 mm 4.5 6.1 3.4 12.5 1.4 1.5 5.7 18.9 6.2 2.8 0.0 1.5 0.0 11.4 HMA thickness 178 mm 3.7 5.7 2.4 14.5 0.6 0.8 2.1 20.7 8.2 1.0 0.3 0.8 0.0 4.1 203 mm 4.0 5.0 3.4 11.2 1.9 1.1 4.2 13.2 9.1 3.4 0.3 1.1 0.0 8.4 305 mm 4.7 8.1 2.4 18.6 0.4 0.9 3.1 30.9 6.3 0.8 0.0 0.9 0.0 6.1 Overall 406 mm 2.9 2.5 3.1 6.6 0.3 2.0 5.1 8.8 4.3 0.6 0.1 2.0 0.0 10.3 203 mm 4.7 7.1 3.1 11.5 2.8 0.7 5.7 18.1 4.8 5.1 0.5 0.7 0.0 11.4 ND 305 mm 5.6 11.2 1.8 24.4 0.4 1.1 1.7 43.4 5.5 0.7 0.0 1.1 0.0 3.4 203 mm 3.1 2.0 3.8 10.8 0.5 1.7 1.9 5.9 15.6 1.0 0.0 1.7 0.0 3.7 305 mm 3.3 3.5 3.2 9.9 0.5 0.5 5.1 12.1 7.7 0.9 0.0 0.5 0.0 10.2 Base thickness D 406 mm 2.9 2.5 3.1 6.6 0.3 2.0 5.1 8.8 4.3 0.6 0.1 2.0 0.0 10.3 DGAB 5.4 5.2 5.5 15.1 0.7 2.2 8.3 18.3 11.9 1.3 0.0 2.2 0.0 16.6 ATB 2.5 4.7 1.1 10.5 0.5 0.4 0.8 17.4 3.6 0.7 0.3 0.4 0.0 1.6 Overall ATB/DGAB 4.8 10.6 1.0 17.0 3.1 0.4 0.5 29.8 4.2 6.3 0.0 0.4 0.0 0.9 DGAB 7.0 9.8 5.1 21.1 1.0 1.8 10.0 35.3 6.9 1.9 0.0 1.8 0.1 20.0 ATB 3.6 7.1 1.4 15.8 0.7 0.5 0.7 27.2 4.4 0.6 0.8 0.5 0.0 1.3 ND ATB/DGAB 4.8 10.6 1.0 17.0 3.1 0.4 0.5 29.8 4.2 6.3 0.0 0.4 0.0 0.9 DGAB 4.3 2.2 5.8 11.1 0.5 2.5 7.2 7.0 15.3 0.9 0.0 2.5 0.0 14.3 Base type D ATB 1.8 3.1 0.9 7.0 0.4 0.4 0.9 10.9 3.1 0.7 0.0 0.4 0.0 1.8 ND 5.1 9.1 2.5 17.9 1.6 0.9 3.7 30.7 5.2 2.9 0.3 0.9 0.0 7.4 Overall D 3.1 2.6 3.4 9.1 0.4 1.4 4.0 8.9 9.2 0.8 0.0 1.4 0.0 8.1 ND 7.0 9.8 5.1 21.1 1.0 1.8 10.0 35.3 6.9 1.9 0.0 1.8 0.1 20.0 DGAB D 4.3 2.2 5.8 11.1 0.5 2.5 7.2 7.0 15.3 0.9 0.0 2.5 0.0 14.3 ND 3.6 7.1 1.4 15.8 0.7 0.5 0.7 27.2 4.4 0.6 0.8 0.5 0.0 1.3 Drainage ATB D 1.8 3.1 0.9 7.0 0.4 0.4 0.9 10.9 3.1 0.7 0.0 0.4 0.0 1.8 Read the entire page →
From page 253... ... 242 Longitudinal Cracking- WP The effects of the design and site factors, in terms of standard deviate, are shown in Figure 5-26. The summary of p-values corresponding to the analyses performed to study the effects of design factors on longitudinal cracking-WP is presented in Table 5-33. Read the entire page →
From page 255... ... 244 Table 5-33 Summary of p-values for comparisons of standard deviates -- Longitudinal cracking-WP By subgrade By climatic zone By subgrade and zone WF WNF DF DNF Design Factor Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C HMA thickness 102 mm vs. 178 mm 0.851 0.420 0.630 0.850 0.560 0.127 0.425 0.440 0.400 .730 0.290 Overall 203 mm vs. Read the entire page →
From page 256... ... 245 Table 5-34 Summary of means of PI for longitudinal cracking-WP By subgrade and zone By subgrade By climatic zone WF WNF DF DNF Design Factors Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C 102 mm 13.9 17.3 11.2 22.3 2.8 0.9 39.5 30.7 1.5 2.8 2.8 0.9 12.7 66.4HMA thickness 178 mm 14.3 17.9 11.3 24.6 2.7 2.6 35.4 31.4 5.4 5.7 0.7 2.6 4.4 66.4 203 mm 13.8 18.0 10.5 23.2 2.5 1.7 37.9 32.5 0.8 3.5 1.9 1.7 12.3 63.5 305 mm 14.3 18.5 10.8 24.7 3.7 2.2 33.0 31.3 6.3 5.7 2.3 2.2 8.2 57.8Overall 406 mm 14.5 14.7 14.3 21.3 1.3 0.6 47.6 27.5 2.7 2.7 0.3 0.6 0.0 95.2 203 mm 14.3 21.0 9.2 26.5 3.0 1.9 34.9 37.4 1.0 4.5 1.9 1.9 15.9 54.0ND 305 mm 15.0 22.9 8.6 27.8 5.2 3.7 27.5 37.8 1.0 7.6 3.6 3.7 13.7 41.3 203 mm 12.9 13.6 12.4 18.5 1.8 1.4 42.3 25.7 0.6 1.9 1.8 1.4 6.8 77.8 305 mm 13.2 12.2 14.0 20.6 1.3 0.0 41.3 22.6 14.3 2.7 0.4 0.0 0.0 82.6 Base thickness D 406 mm 14.5 14.7 14.3 21.3 1.3 0.6 47.6 27.5 2.7 2.7 0.3 0.6 0.0 95.2 DGAB 15.3 19.8 11.7 25.2 2.1 2.5 44.1 35.0 1.6 3.8 0.9 2.5 15.3 72.9 ATB 12.0 14.0 10.3 19.5 2.5 1.0 31.5 24.1 5.9 5.2 0.7 1.0 1.2 61.7Overall ATB/DGAB 16.8 22.2 12.5 30.9 5.2 1.9 35.8 42.5 1.8 3.1 6.7 1.9 9.8 61.8 DGAB 16.9 27.7 9.2 32.2 3.2 5.5 39.5 47.9 0.9 5.5 1.6 5.5 31.5 47.5 ATB 10.7 17.1 5.2 20.1 3.9 1.0 18.3 26.7 0.3 9.7 0.1 1.0 3.1 33.5ND ATB/DGAB 16.8 22.2 12.5 30.9 5.2 1.9 35.8 42.5 1.8 3.1 6.7 1.9 9.8 61.8 DGAB 14.2 15.2 13.5 21.4 1.3 0.4 47.2 28.6 2.1 2.7 0.4 0.4 4.5 89.9 Base type D ATB 12.8 11.9 13.7 19.1 1.6 0.9 40.3 22.3 9.7 2.1 1.2 0.9 0.0 80.5 ND 14.7 22.0 8.9 27.2 4.1 2.8 31.2 37.6 1.0 6.1 2.8 2.8 14.8 47.6Overall D 13.5 13.5 13.6 20.2 1.5 0.7 43.7 25.3 5.9 2.4 0.8 0.7 2.3 85.2 ND 16.9 27.7 9.2 32.2 3.2 5.5 39.5 47.9 0.9 5.5 1.6 5.5 31.5 47.5DGAB D 14.2 15.2 13.5 21.4 1.3 0.4 47.2 28.6 2.1 2.7 0.4 0.4 4.5 89.9 ND 10.7 17.1 5.2 20.1 3.9 1.0 18.3 26.7 0.3 9.7 0.1 1.0 3.1 33.5 Drainage ATB D 12.8 11.9 13.7 19.1 1.6 0.9 40.3 22.3 9.7 2.1 1.2 0.9 0.0 80.5 Read the entire page →
From page 257... ... 246 Longitudinal Cracking- NWP The effects of the design and site factors, in terms of standard deviate, are shown in Figure 5-27. The summary of p-values corresponding to the analyses performed to study the effects of design factors on longitudinal cracking-NWP is presented in Table 5-35. Read the entire page →
From page 258... ... 247 This page is intentionally left blank. Read the entire page →
From page 260... ... 249 Table 5-35 Summary of p-values for comparisons of standard deviates -- Longitudinal cracking-NWP By subgrade By climatic zone By subgrade and zone WF WNF DF DNF Design Factor Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C HMA thickness 102 mm vs. 178 mm 0.304 0.510 0.440 0.430 0.490 0.120 0.230 0.250 0.940 0.460 0.790 Overall 203 mm vs. Read the entire page →
From page 261... ... 250 Table 5-36 Summary of means of PI for longitudinal cracking-NWP By subgrade and zone By subgrade By climatic zone WF WNF DF DNF Design Factors Comparison Overall Fine Coarse WF WNF DF DNF F C F C F C F C 102 mm 47.7 35.9 55.8 78.0 14.9 77.2 6.7 59.9 97.2 13.7 15.7 77.2 4.1 9.3 HMA thickness 178 mm 49.0 40.8 54.9 77.7 15.6 84.1 4.3 66.6 90.5 15.7 15.5 84.1 0.8 7.8 203 mm 48.9 37.4 56.4 79.9 16.8 84.2 4.0 65.2 93.6 14.9 18.1 84.2 4.2 3.8 305 mm 49.0 40.8 55.1 79.1 13.7 77.9 9.1 66.8 93.9 13.4 13.9 77.9 1.7 16.6Overall 406 mm 45.4 35.0 53.5 70.5 15.1 78.6 0.0 52.6 94.3 17.3 13.6 78.6 0.0 0.1 203 mm 52.4 47.7 55.5 88.0 13.9 89.3 4.6 81.2 94.8 19.9 9.9 89.3 3.0 6.3 ND 305 mm 46.9 35.9 54.6 77.9 9.8 78.1 10.1 61.1 96.6 10.4 9.4 78.1 2.8 17.4 203 mm 43.6 20.4 57.7 66.7 21.2 76.6 3.1 36.6 91.8 7.4 30.3 76.6 6.1 0.0 305 mm 52.2 47.4 55.8 80.8 19.6 77.7 7.7 74.0 89.8 18.0 20.7 77.7 0.0 15.5 Base thickness D 406 mm 45.4 35.0 53.5 70.5 15.1 78.6 0.0 52.6 94.3 17.3 13.6 78.6 0.0 0.1 DGAB 47.8 34.2 56.6 77.0 16.3 79.5 10.2 58.5 94.3 14.9 17.2 79.5 4.6 15.7 ATB 48.9 41.6 54.4 77.9 15.4 80.2 2.7 65.7 93.4 16.2 14.8 80.2 0.7 4.7 Overall ATB/DGAB 48.3 39.6 54.6 79.5 12.3 85.0 0.7 67.2 93.7 10.3 13.5 85.0 1.3 0.0 DGAB 47.0 28.8 57.2 81.9 11.1 81.0 15.6 56.8 98.7 12.4 10.2 81.0 5.5 25.7 ATB 53.1 52.7 53.3 86.6 12.2 85.2 5.9 80.5 94.7 22.7 5.2 85.2 1.8 9.9 ND ATB/DGAB 48.3 39.6 54.6 79.5 12.3 85.0 0.7 67.2 93.7 10.3 13.5 85.0 1.3 0.0 DGAB 48.3 37.0 56.2 74.4 19.8 78.5 6.6 59.1 91.4 16.6 21.9 78.5 4.1 9.1 Base type D ATB 46.1 33.8 55.1 71.9 17.5 76.8 0.6 55.0 92.6 11.9 21.2 76.8 0.0 1.3 ND 49.6 41.6 55.0 82.8 11.9 83.7 7.4 70.6 95.7 15.2 9.7 83.7 2.9 11.9Overall D 47.2 35.4 55.7 73.1 18.6 77.6 3.6 56.9 92.0 14.2 21.6 77.6 2.0 5.2 ND 47.0 28.8 57.2 81.9 11.1 81.0 15.6 56.8 98.7 12.4 10.2 81.0 5.5 25.7DGAB D 48.3 37.0 56.2 74.4 19.8 78.5 6.6 59.1 91.4 16.6 21.9 78.5 4.1 9.1 ND 53.1 52.7 53.3 86.6 12.2 85.2 5.9 80.5 94.7 22.7 5.2 85.2 1.8 9.9 Drainage ATB D 46.1 33.8 55.1 71.9 17.5 76.8 0.6 55.0 92.6 11.9 21.2 76.8 0.0 1.3 Read the entire page →
From page 262... ... 251 5.6.4 Effect of Experimental Factors on Pavement Response This section of the report is a discussion of the results from analyses of FWD data (pavement response) of the SPS-1 sections. Read the entire page →
From page 263... ... 252 types. Furthermore, among pavement sections built on DGAB, those with drainage have shown lesser peak deflections than those without drainage. Read the entire page →
From page 264... ... 253 reasonable, as this deflection (d6) represent the subgrade strength, which is independent of the HMA thickness and pavement temperature. Read the entire page →
From page 265... ... 254 Table 5-37 Summary of p-values from ANOVA for determining the effect of design factors on flexible pavement response -- Overall Performance Measures Design Factor Peak Deflection (do) Far Deflection (d6) Read the entire page →
From page 266... ... 255 5.7 APPARENT RELATIONSHIP BETWEEN RESPONSE AND PERFORMANCE In this section of the report the observations regarding apparent relationships between flexible pavement response (FWD testing) and performance are presented. Read the entire page →
From page 267... ... 256 • Pavement distresses etc. To consider the effect of various variables on the response at the same time, the multiple linear regression technique was used. Read the entire page →
From page 268... ... 257 • The higher the "subgrade" deflection, d6 (deflection at the outer most sensor, or 60 inches in this case) , the higher d0 will be (p=0.000) Read the entire page →
From page 269... ... 258 in that higher the SCI or lower the AREA, higher is the cracking. Similarly, Figure 5-31 is the relationship between BDI and future rutting for the same site. Read the entire page →
From page 270... ... 259 y = 1.7875x + 126.76 R2 = 0.1661 0 50 100 150 200 250 300 350 400 1 10 100 1000 SCI Fa tig ue C ra ck in g (s qm ) Figure 5-28 Fatigue cracking and SCI relationship─ State (20) Read the entire page →
From page 271... ... 260 Tables 5-39 through 5-41 are summaries of correlation coefficients from the bivariate analyses for three performances (fatigue cracking, rutting and roughness) and various deflection parameters between all the sites. Read the entire page →
From page 272... ... 261 Table 5-39 Summary of correlations for deflections and DBPs with fatigue cracking State Area ES/Esg ES Esg d0 d6 SCI BDI Zone SG 31 Nebraska -0.79 -0.66 -0.64 -0.37 0.90 0.43 0.94 0.91 WF F 26 Michigan 0.48 0.59 0.42 0.21 -0.42 -0.03 -0.46 -0.45 WF F 19 Iowa -0.45 -0.11 -0.09 0.05 0.41 0.15 0.55 0.49 WF F 20 Kansas -0.38 -0.26 -0.25 -0.14 0.33 -0.01 0.41 0.30 WF F 39 Ohio -0.66 -0.44 -0.44 -0.43 0.58 0.20 0.63 0.63 WF F 55 Wisconsin -0.46 -0.38 -0.37 -0.02 0.38 0.04 0.51 0.22 WF C 10 Delaware -0.93 -0.78 -0.65 -0.04 0.72 -0.03 0.93 0.73 WF C 5 Arkansas -0.07 -0.02 -0.19 -0.54 0.34 0.59 0.17 0.34 WF C 51 Virginia -0.72 -0.57 -0.58 -0.32 0.75 0.04 0.79 0.75 WNF F 1 Alabama -0.79 -0.68 -0.64 -0.08 0.72 -0.27 0.75 0.73 WNF F 48 Texas -0.48 -0.33 -0.57 -0.49 0.74 0.65 0.78 0.58 WNF C 40 Oklahoma -0.47 -0.43 -0.59 -0.16 0.25 -0.05 0.28 0.28 WNF C 12 Florida -0.40 -0.37 -0.40 0.14 0.50 -0.12 0.46 0.55 WNF C 30 Montana -0.36 -0.31 -0.58 -0.74 0.53 0.83 0.34 0.42 DF C 32 Nevada -0.49 -0.355 -0.31 0.10 0.38 -0.17 0.41 0.29 DF C 35 New Mexico 0.19 0.22 0.33 -0.14 0.31 -0.01 -0.14 0.60 DNF F 4 Arizona -0.13 -0.22 0.06 0.53 -0.10 -0.55 -0.03 -0.03 DNF C (-) Read the entire page →
From page 273... ... 262 Table 5-40 Summary of correlations for deflections and DBPs with rut depth State Area ES/Esg ES Esg d0 d6 SCI BDI Zone SG 31 Nebraska -0.45 -0.48 -0.24 0.29 0.28 0.06 0.41 0.29 WF F 26 Michigan 0.32 0.53 0.41 0.10 -0.14 -0.04 -0.16 -0.14 WF F 19 Iowa -0.56 -0.43 -0.41 -0.22 0.40 0.13 0.43 0.46 WF F 20 Kansas -0.80 -0.55 -0.59 -0.23 0.76 0.11 0.82 0.78 WF F 39 Ohio -0.86 -0.88 -0.88 -0.72 0.79 0.51 0.75 0.76 WF F 55 Wisconsin 0.26 0.31 0.37 0.37 -0.60 -0.45 -0.48 -0.65 WF C 10 Delaware -0.72 -0.55 -0.62 -0.25 0.66 0.37 0.73 0.61 WF C 5 Arkansas 0.37 0.51 0.51 0.03 -0.11 -0.02 -0.20 -0.03 WF C 51 Virginia -0.58 -0.40 -0.39 -0.22 0.69 0.02 0.78 0.68 WNF F 1 Alabama -0.51 -0.34 -0.26 0.23 0.63 -0.30 0.73 0.69 WNF F 48 Texas 0.65 0.62 0.80 0.37 -0.67 -0.28 -0.65 -0.62 WNF C 40 Oklahoma 0.02 0.23 -0.15 -0.43 0.60 0.67 0.54 0.55 WNF C 12 Florida 0.56 0.60 0.40 -0.62 -0.33 0.66 -0.44 -0.39 WNF C 30 Montana -0.62 -0.66 -0.70 -0.59 0.68 0.56 0.60 0.63 DF C 32 Nevada 0.05 -0.002 -0.03 -0.31 0.03 0.13 -0.10 0.25 DF C 35 New Mexico 0.35 0.27 0.31 -0.24 -0.46 0.25 -0.47 -0.09 DNF F 4 Arizona -0.19 -0.31 -0.33 -0.20 0.06 0.02 0.05 0.04 DNF C (-) Read the entire page →
From page 274... ... 263 Table 5-41 Summary of correlations for deflections and DBPs with IRI State Area ES/Esg ES Esg d0 d6 SCI BDI Zone SG 31 Nebraska -0.61 -0.44 -0.54 -0.43 0.66 0.49 0.62 0.72 WF F 26 Michigan -0.75 -0.71 -0.78 -0.82 0.78 0.74 0.73 0.76 WF F 19 Iowa -0.53 -0.31 -0.28 0.04 0.18 -0.12 0.30 0.25 WF F 20 Kansas -0.34 -0.31 -0.38 -0.38 0.40 -0.16 0.27 0.42 WF F 39 Ohio -0.79 -0.65 -0.65 -0.58 0.84 0.37 0.85 0.85 WF F 55 Wisconsin 0.37 0.45 0.50 0.23 -0.54 -0.04 -0.46 -0.54 WF C 10 Delaware -0.71 -0.60 -0.68 -0.36 0.73 0.28 0.68 0.76 WF C 5 Arkansas -0.02 -0.03 -0.17 -0.41 0.21 0.42 0.05 0.21 WF C 51 Virginia -0.70 -0.50 -0.55 -0.38 0.78 0.06 0.83 0.77 WNF F 1 Alabama -0.47 -0.32 -0.31 -0.31 0.69 0.23 0.66 0.69 WNF F 48 Texas 0.38 0.44 0.36 -0.17 -0.11 0.15 -0.20 -0.09 WNF C 40 Oklahoma 0.45 0.49 0.25 -0.35 0.17 0.56 0.10 0.10 WNF C 12 Florida -0.31 -0.31 -0.42 0.14 0.47 -0.15 0.38 0.51 WNF C 30 Montana -0.55 -0.61 -0.69 -0.62 0.63 0.62 0.50 0.55 DF C 32 Nevada -0.47 -0.229 -0.20 -0.16 0.71 0.44 0.72 0.68 DF C 35 New Mexico 0.39 0.50 0.49 -0.31 -0.02 0.33 -0.35 0.29 DNF F 4 Arizona -0.56 -0.46 -0.47 -0.08 0.63 0.05 0.64 0.65 DNF C (-) Read the entire page →
From page 275... ... 264 5.7.3 Overall Analyses -- Predictive Relationships This section summarizes the findings of apparent relationships between initial response (FWD deflection or deflection base indices) and future pavement performance (cracking, rutting and roughness) Read the entire page →
From page 276... ... 265 of various pavements. Thus the probable cause of this distress type may be the environment and not the loading (traffic) Read the entire page →
From page 277... ... 266 Age (years) Read the entire page →
From page 278... ... 267 SCI F at ig u e C ra ck in g (s q -m ) Read the entire page →
From page 279... ... 268 Area Factor F at ig u e C ra ck in g ( sq -m ) Read the entire page →
From page 280... ... 269 Area Factor L C _W P ( m ) Read the entire page →
From page 281... ... 270 Area Factor L C _N W P ( m ) Read the entire page →
From page 282... ... 271 Area Factor T ra n sv er se C ra ck in g ( m ) Read the entire page →
From page 283... ... 272 BDI R u t d ep th ( m m ) Read the entire page →
From page 285... ... 274 5.7.4 Dynamic Load Response for OH (39) test sections This section presents the summary of findings from the analysis of Dynamic Load Response (DLR) Read the entire page →
From page 286... ... 275 y = 0.3994x0.8073 R2 = 0.8998 0 5 10 15 20 25 30 35 0 50 100 150 200 250 Long. Strains (micro-strains) Read the entire page →
From page 287... ... 276 y = 0.7727x0.3798 R2 = 0.7164 0.0 0.5 1.0 1.5 2.0 2.5 0 5 10 15 20 Stress at top of subgrade (psi) Read the entire page →
From page 288... ... 277 5.8 SYNTHESIS OF RESULTS FROM ANALYSES This section of the report summarizes the findings from various analyses performed on SPS-1 data. The methods employed in this study were explained in Chapter 4 and the results obtained from these analyses were presented above in this chapter. Read the entire page →
From page 289... ... 278 5.8.1 Effects of structural factors for flexible pavements -- SPS-1 experiment This section is subdivided into three parts: (i) pavement performance, (ii) Read the entire page →
From page 290... ... 279 Among un-drained pavements, on average, an increase in HMA surface thickness from 102 mm (4-inch) to 178 mm (7-inch) Read the entire page →
From page 291... ... 280 Marginal main effects of drainage, HMA thickness, and base thickness on structural rutting were observed. Pavements with "thin" [102 mm (4-inch) Read the entire page →
From page 292... ... 281 drainage among pavements with DGAB is considerable in improving rut performance among sections located in WNF zone. On the other hand an increase in base thickness from 203 mm (8inch) Read the entire page →
From page 293... ... 282 Transverse Cracking The effect of base thickness on transverse cracking is insignificant, at this point. Pavements constructed with DGAB have more transverse cracking than those with ATB/DGAB and ATB, while pavements with ATB have shown the least amount of cracking. Read the entire page →
From page 294... ... 283 Among pavements built on fine-grained soils, those built with DGAB have shown more longitudinal cracking-WP, and those built with ATB have shown the least amount of cracking. This main effect of base type was statistically and operationally significant. Read the entire page →
From page 295... ... 284 transformation has been applied to the three response indicators to fulfill the ANOVA assumptions. The following discussion summarizes the effects of design and site factors on each of the response parameters. Read the entire page →
From page 296... ... 285 AREA The interactions between HMA thickness and base type, base thickness and base type, and, drainage and base type have significant effects on the AREA parameter. Among pavement sections built on DGAB, those with "thin" HMA surface layer have lower AREA values compared to those with "thick" HMA surface layer, implying that the upper layers of these pavement sections are "less stiff". Read the entire page →
From page 297... ... 286 Table 5-42 ‘Simplified' summary of effects of design and site factors for flexible pavements Performance Measures Response Measures Longitudinal cracking Design Factor Fatigue cracking Rutting Roughness Transverse cracking WP NWP Peak deflection do Peak deflection d6 Area Factor HMA thickness Base type Base thickness Drainage Climatic Zone Subgrade type Note: This table is solely for the purpose of summarizing some of the effects in a ‘simple' format. The reader is urged to read relevant text in the report for a better understanding. Read the entire page →
From page 298... ... 287 5.8.1.3 Apparent Relationship between Response and Performance Two types of relations between flexible pavement response under (FWD testing) and performance were explored for the SPS-1 pavement sections -- explanatory and predictive. Read the entire page →
From page 299... ... 288 (fatigue cracking, rutting and roughness) at the site level. Read the entire page →
From page 300... ... 289 compared to pavements with high BDI. These pavements could have experienced mix-related rutting (not structural rutting) Read the entire page →
From page 301... ... 290 This page is intentionally left blank. Read the entire page →

From page 166...

... 155 CHAPTER 5 - ANALYSIS RESULTS FOR THE SPS-1 EXPERIMENT 5.1 INTRODUCTION The purpose of this chapter is to provide a summary of findings from the previous studies and the results of the various analyses conducted for the SPS-1 experiment on flexible pavements in this study. The performance and structural response indicators used in the analysis include fatigue (alligator)