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From page 2... ... 2 CHAPTER 2 RESEARCH APPROACH 2.1 INTRODUCTION The first rigid pavements, constructed of Portland cement concrete (PCC) , were placed directly on the subgrade (Ahlvin, 1991; Fitch, 1996) Read the entire page →
From page 3... ... 3 does not adequately represent the behavior of the pavement between these bond condition extremes. The characterization of slab-base-foundation interaction extends beyond friction, bond, and vertical support; it includes the concept of built-in curl, a concept proposed by Eisenmann and Leykauf (1990) Read the entire page →
From page 4... ... Figure Erosion r base laye reviewed test, jettin performe cylinder of the rot test for er standard 1996) Read the entire page →
From page 5... ... 5 behavior due to temperature response, loading, creep effects, existing damage, etc. That is, the analyses lack a control against which slab-base interaction may be identified. Read the entire page →
From page 6... ... 6 analysis focused on (a) the effect of base type on pavement performance and (b) Read the entire page →
From page 7... ... Figure 2.3.2 B The defle structura program, sections u calculatio LTPP da values fro stabilized these sec subgrade 1993 des A deflection designate conducte from the calculate layer. Th the seaso T (2001) Read the entire page →
From page 8... ... 8 scale. Thus, the research in this study included the development of a back calculation procedure using edge- or center-loaded data, as backcalculated layer properties at both locations may reveal factors that impact both slab-base interaction and the likelihood of pavement distress. Read the entire page →
From page 9... ... 9 program, ISLAB2005 (Khazanovich and Ioannides, 1994) Read the entire page →
From page 10... ... 2.4.2.1 B The AAS the AASH support t The effec surface u including composit subgrade concrete modulus computed process i the pavem AASHTO Fig The abov foundatio pavemen Minnesot Decembe greater; i aggregate stiffness 93 design umping k-va HTO M-E p TO M-E st hrough a Wi tive dynam sing the elas the base lay e pavement resilient mo slab and bas testing. Usin using JUL s repeated fo ent layers. Read the entire page →
From page 11... ... Figur The AAS (ARA, 20 critical st FWD bas calculatio 2.4.2.2 B The deter accounts effective slab. Thu stress res T the AASH cracking 0213. Read the entire page →
From page 12... ... Figure 2.4.2.3 D As discu distress p there are Three pe model fo model fo Transver framewo cracking where CR and FD i where where n i type, load (respectiv 5. Sensitivit istress mode ssed, both E rediction ac features rela rformance m r JPCP proje r JPCP proje se cracking rk, it was ne model, whic ܥܴ ൌ is percent s total bottom ܨܦ s the applie level, equi ely) Read the entire page →
From page 13... ... 13 log൫ ௜ܰ,௝,௞,௟,௠,௡൯ ൌ ܥ௔ ∙ ቆ ܯܴ௜ߪ௜,௝,௞,௟,௠,௡ቇ ஼್ ൅ ܣଷ 3 where ܯܴ௜ is the PCC modulus of rupture at age i in psi; ߪ௜,௝,௞,௟,௠,௡ is the critical stress for associated indices in psi; and Ca and Cb are calibration constants (AASHTO, 2008) Read the entire page →
From page 14... ... Figure 6 For granu in the mo trend pre have line This indi character permanen It (bonded procedur cracking unbonded friction (L F to the LO M-E uses damage a AASHTO this way, (outside o paramete A bonded c . Effect of lar bases, th del. Read the entire page →
From page 15... ... 15 except those using cement-treated bases (CTB) Read the entire page →
From page 16... ... (a) Figure The case to unders structura structura loading. Read the entire page →
From page 17... ... 17 existing AASHTO M-E framework and (2) incorporating these models into JPCP transverse cracking predictions. Read the entire page →
From page 18... ... propertie slab expe (2) the co between joint load T investiga M-E proc observed subset of Figure In genera the mode for each r for granu model wa Punchout per mile associate s (thickness riences the ncrete slab the slab and transfer eff he effect of ted using th edure (Sach faulting by projects by 9. Read the entire page →
From page 19... ... 19 where PO is punchouts per mile, C3 through C5 are global calibration constants, and FD is total fatigue damage determined using Miner's hypothesis ܨܦ ൌ෍݊௜,௝ ௜ܰ,௝ 13 where n is the applied number of load applications; indices i and j refer to age and load level, respectively; and ௜ܰ,௝ is the allowable number of load repetitions at age i and load magnitude j such that log൫ ௜ܰ,௝൯ ൌ ܥ௔ ∙ ቆܯܴ௜ߪ௜,௝ ቇ ஼್ െ 1 14 to determine N given ܯܴ௜ the slab modulus of rupture at age i in psi; ߪ௜,௝, the critical stress at time increment i due to load magnitude j in psi; and calibration constants Ca and Cb (AASHTO, 2008) Read the entire page →
From page 20... ... An analy Thus this punchout In was inve procedur punchout presents Figure A challen generally ܿݓ ߝ௦௛௥ ߙ௉஼஼ Δ ఍ܶ ܿଶ ߪ௅௢௡௚ ܧ௉஼஼ ܥ௖ sis of Equat study re-ev predictions addition, th stigated usin e (Sachs et a s by project linear regres 10. AASTH ge of the G fail in punc  Averag  Unrestr  PCC co  Drop in temper  Second  Maxim  PCC el  Local c ion 5 shows aluated both . Read the entire page →
From page 21... ... non-zero AASHTO ability of Whereas improve address i 2.5 R The follo using pav character and analy 2.5.1 C Characte edge- and 2.5.1.1 B As discu accounte of subgra to the po interactio conventio into slab for other developm FWD bas base type Figure The deve procedur Westerga punchouts p M-E calib the model t previous ca model fitnes ssues with la ESEARCH wing subsec ement data ized slab-ba sis. haracteriza rization of s center-load ase layer an ssed above, d for the eff de reaction. Read the entire page →
From page 22... ... 22 pressure distributed over a circular area. This solution relates the deflections of FWD sensors with the applied FWD load and pavement system properties as follows: ݓሺݎ௜ሻ ൌ ݌݇ ௜݂ ቀ ܽ ℓ , ݎ௜ ℓቁ 17 where ݓሺݎ௜ሻ is the deflection of sensor i, k is the modulus of subgrade reaction; p is the applied pressure; and ௜݂ is a non-dimensional function relating ri, the distance from the center of loaded area to sensor i, and a, the radius of a FWD load plate, given ℓ, the radius of relative stiffness of the pavement. Read the entire page →
From page 23... ... 23 used to develop rapid solutions for functions fi for FWD sensor locations at 0, 8, 12, 18, 36, and 60 inches from the center of the FWD plate. Those rapid solutions were used to develop an efficient procedure for back calculation of layer properties given FWD basins collected at the slab edge and slab interior using Equations 20 and 21. Read the entire page →
From page 24... ... 24 Figure 12. Transformed section concept (from Khazanovich and Gotlif 2002) Read the entire page →
From page 25... ... 25 ܦ௜ ൌ ܧ௜3ሺ1 െ ߤଶሻ ሺ݄௜ ଷ െ 3݄௜ଶܾ௜ ൅ 3݄௜ܾ௜ଶሻ 26 for layers ݅ ൌ 1,2, where hi is layer thickness, Ei is layer modulus, and μ is the Poisson ratio (assumed to be equal for the two layers) , and where parameters b1 and b2 are defined as ܾଵ ൌ 0.5ܧଶ ∗݄ଶଶ ൅ ݄ଵΛ Λ ൅ ܧଶ∗ ൅ Λ Λ ቆ Λሺ0.5ܧଵ∗݄ଵଶ ൅ ݄ଵΛሻ െ ሺܧଵ∗݄ଵ ൅ Λሻሺെ0.5ܧଶ∗݄ଶଶ ൅ ݄ଵΛሻ ܧଵ∗ܧଶ∗݄ଵ݄ଶ ൅ ܧଵ∗݄ଵΛ ൅ ܧଶ∗݄ଶΛ ቇ 27 ܾଶ ൌ Λ ሺ0.5ܧଵ∗݄ଵଶ ൅ ݄ଵΛሻ െ ሺܧଵ∗݄ଵ ൅ Λሻሺെ0.5ܧଶ∗݄ଶଶ ൅ ݄ଵΛሻ ܧଵ∗ܧଶ∗݄ଵ݄ଶ ൅ ܧଵ∗݄ଵΛ ൅ ܧଶ∗݄ଶΛ 28 and the star notation on E1 and E2 denote ܧ௜∗ ൌ ܧ௜1 െ ߤଶ 29 The value of Λ associated with the minimal error ൬஽೐೑೑ି஽೐ೞ೟஽೐೑೑ ൰ for a given test (applied iteratively) Read the entire page →
From page 26... ... Adu-Gya decompo the origin the sum o recombin The deve given sec A decompo within th using inf distance passes in spacing, Figure cu Thus, the informati This shap built-in c interest w and for e entire du 2.5.2 D The AAS performa concrete modifica mfi et al. (2 sition of dat al signal, y( f its intrinsi ed with the ݕሺݔሻ loped EMD tion and ob s implied by sition, a seri e larger sign ormation on between loc Figure 13a; and they rep 13. Read the entire page →
From page 27... ... 27 2.5.2.1 Transverse cracking The modified JPCP transverse cracking prediction model to account for slab-base interaction considers all of the inputs in a manner that is nearly identical to the AASHTO M-E procedure. The modified AASHTO M-E damage calculation and performance prediction process closely follows the AASHTO procedure with additional steps to account for the gradual deterioration of the slab-base interaction coefficient Λ. Read the entire page →
From page 28... ... 28 ݄௘௙௙ ൌ ඨ12 ሺ1 െ ߤଶሻܦ௘௙௙ ܧ௉஼஼ య 32 where μ is the Poisson ratio for the PCC and base layers, EPCC is the PCC elastic modulus, and Deff is the effective flexural stiffness, which is identical to the parameter Dest expressed in Equation 25. Thus, the radius of relative stiffness, ℓ, uses the modified effective thickness heff that considers Λ and is ℓ ൌ ඩ ܧ௉஼஼൫݄௘௙௙൯ ଷ 12݇ ቂ1 െ ൫ߤ௘௙௙൯ଶቃ ర 33 where k is the coefficient of subgrade reaction. Read the entire page →
From page 29... ... 29 ߶ ൌ 2ߙ௉஼஼ሺ1 ൅ ߤ௉஼஼ሻℓ ଶ ݄௘௙௙ଶ ݇ ߛ௘௙௙ Δ ௘ܶ௙௙ 37 where hPCC is the PCC slab thickness, PCC is the PCC coefficient of thermal expansion, and all others are as above. The next sub-step is to compute the adjusted Load-to-Pavement-Weight ratio (i.e., the normalized load) Read the entire page →
From page 30... ... Finally, g determin slab-base accounts calculate where σef neutral ax nonlinear the analy interface Revised t computat distributi distributi procedur combinat T loads as a nonlinear in this pr critical lo standard at the mi left. For load with on the rig Figure 1 T linear tem frequency iven stresse ed. Read the entire page →
From page 31... ... 31 distribution from the previous step. The temperature frequency distribution for each month, which is developed only for the standard load and wheel offset conditions, is used in the fatigue analysis for all axle loads and offsets conditions. Read the entire page →
From page 32... ... 32 Table 4. Example of frequency distribution of probability of a given combination of TL and TNL for a given hour of a specific calendar month Month Hour TL Probability of given value of TNL 2 1.75 1.5 1.25 1 0.75 0.5 0.25 0 ‐0.25 ‐0.5 ‐0.75 ‐1 ‐1.25 ‐1.5 ‐1.75 ‐2 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 ‐2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 ‐4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 ‐6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 ‐8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 ‐10 0 0 0 0 0 0 0 0.0002 0.0003 0 0 0 0 0 0 0 0 1 1 ‐12 0 0 0 0 0 0 0 0.0012 0.0025 0.0009 0.0002 0 0 0 0 0 0 1 1 ‐14 0 0 0 0 0 0 0 0 0.0076 0.0353 0.0078 0 0 0 0 0 0 1 1 ‐16 0 0 0 0 0 0 0 0 0.0116 0.1458 0.1052 0.0033 0 0 0 0 0 1 1 ‐18 0 0 0 0 0 0 0 0 0.0054 0.1304 0.2457 0.0136 0 0 0 0 0 1 1 ‐20 0 0 0 0 0 0 0 0 0 0.0241 0.1377 0.0322 0.0004 0 0 0 0 1 1 ‐22 0 0 0 0 0 0 0 0 0 0.0056 0.0435 0.0227 0.0008 0 0 0 0 1 1 ‐24 0 0 0 0 0 0 0 0 0 5E‐05 0.0062 0.009 0.0002 0 0 0 0 1 1 ‐26 0 0 0 0 0 0 0 0 0 0 0.0001 0.0004 0 0 0 0 0 1 1 ‐28 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 ‐30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 ‐2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 ‐4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 ‐6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 ‐8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 ‐10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 ‐12 0 0 0 0 0 0 0 3E‐05 0.0029 0.0014 0 0 0 0 0 0 0 1 2 ‐14 0 0 0 0 0 0 0 8E‐05 0.0093 0.0282 0.0027 0 0 0 0 0 0 1 2 ‐16 0 0 0 0 0 0 0 0 0.0218 0.1439 0.0395 0.0005 0 0 0 0 0 1 2 ‐18 0 0 0 0 0 0 0 0 0.0053 0.176 0.201 0.0056 0 0 0 0 0 1 2 ‐20 0 0 0 0 0 0 0 0 1E‐06 0.0601 0.1628 0.0125 0 0 0 0 0 1 2 ‐22 0 0 0 0 0 0 0 0 0 0.0127 0.0734 0.0176 0 0 0 0 0 1 2 ‐24 0 0 0 0 0 0 0 0 0 0.001 0.0107 0.005 0 0 0 0 0 1 2 ‐26 0 0 0 0 0 0 0 0 0 0 0.001 0.0015 0 0 0 0 0 1 2 ‐28 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 ‐30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Table 5. Read the entire page →
From page 33... ... 33 Modifications to the damage calculation in the modified JPCP transverse cracking prediction model. This step involves the calculation of accumulated top-down and bottom-up damage in the slab given the structure response (i.e. Read the entire page →
From page 34... ... 34 ܹ ൌ ܽ ଶ 2ܧන 2ݖ ݄ ߪ௕dz ௛ ଶ ௛ ଶି௔ ൌ ܽ ଷߪ௕ଶ 2ܧ ൤1 െ 2 ܽ ݄ ൅ 4 3 ቀ ܽ ݄ቁ ଶ ൨ 47 Consider a case when the stress varies linearly through depth ݖ within a characteristic length ܽ, but the manner of variation in stress is not proportional to ݖ. This may happen when a beam is subjected to bending and a nonlinear temperature distribution. Read the entire page →
From page 35... ... 35 surface curing conditions resembles air-curing conditions, it is reasonable to expect that there will exist a difference in the flexural strength of the two surfaces of the slab. This phenomenon was incorporated into the original development of the AASHTO M-E procedure through the use of a strength adjustment factor (ARA, 2004) Read the entire page →
From page 36... ... the full c are summ EROD. I total faul Figure It can be individua Moreove sensitivit predicted recomme Developm faulting m not docum team recr goal bein the origin AASHTO results in comparis inches) Read the entire page →
From page 37... ... Figure 1 Base load slab-base paramete paramete (LTEtotal) where LT LTEdowel interlock investiga documen that the o    Although assigned recreation climates type.) Read the entire page →
From page 38... ... sensitivit assumed squared e where Fa Figure 17 different Fig One can faulting i values fo support, adjustme T granular 1 2 3 y of model p for each bas rror, SSE, b ܵܵܧ ൌ ultobs is the illustrates t by base type ure 17. Sen observe in F s quite sensi r the base L a decision w nts to T. Read the entire page →
From page 39... ... 39 After the model was re-calibrated for granular bases, the sensitivity of joint faulting to base LTE and T was investigated for sections with CTB and PATB bases. The combinations of these parameters resulting in the least discrepancy between the predicted and observed joint faulting were recommended as new default parameters. Read the entire page →
From page 40... ... Figu The first base. The 1 2 3 After the stabilized and 24) Read the entire page →
From page 41... ... 41 same input files and produce identical output files to those of the original AASHTO M-E JPCP cracking and faulting performance prediction programs. To simplify the use of the alternative JPCP transverse cracking model, the companion software was developed using Java and built to run alongside the AASHTO M-E software on Windows operating systems. Read the entire page →

From page 2...

... 2 CHAPTER 2 RESEARCH APPROACH 2.1 INTRODUCTION The first rigid pavements, constructed of Portland cement concrete (PCC) , were placed directly on the subgrade (Ahlvin, 1991; Fitch, 1996)