Jointed Rigid Pavement Research Articles

Correlations and preliminary validation of the laboratory monotonic overlay test (OT) data to reflective cracking performance of in-service field highway sections

Reflective cracking is one of the dominant distress modes occurring when hot-mix asphalt (HMA) overlays are placed over existing cracked flexible and/or jointed rigid pavements. In the laboratory setting, there are various tests – both of dynamic and monotonic loading modes – that can be used to measure, characterize, and quantify the cracking resistance potential of HMA mixes. However, one key challenge with most of these laboratory tests is correlations and validation with field performance data. Quite often, field data availability is a challenge or otherwise, needs costly long-term performance monitoring. Using the Texas flexible pavements and overlays database, namely the Texas Data Storage System (DSS), as the data source, this study was conducted to correlate and preliminarily validate the laboratory monotonic-loading overlay tester (OT) to the field crack performance of in-service highway sections. As excerpted from the DSS, four HMA mixes and six in-service highway sections (overlays) were used. Overall, the monotonic-loading OT test exhibited promising potential as a repeatable test (coefficient of variation [COV] < 30%) for evaluating and quantifying the cracking resistance potential of HMA mixes in the laboratory relative to the field performance of in-service highway sections. In particular, the following HMA fracture parameters, fracture energy (FE), tensile strength (σt), FE Index, and peak load (Pmax) from the monotonic-loading OT test, with COV values less than 30%, were able to statistically differentiate the HMA mixes (statistical groups ≥ 2) and also correlated well (coefficient of determination [R2] > 60%) with the measured field cracking performance data.

Toward the Development of Load Transfer Efficiency Evaluation of Rigid Pavements by a Rolling Wheel Deflectometer

The jointed rigid pavement is currently evaluated by the Falling weight deflectometer which is rather slow for the testing of the jointed pavements. Continuous nondestructive evaluation of rigid pavements with a rolling wheel deflectometer can be used to measure the load transfer and is investigated. Load transfer is an important indicator of the rigid pavement’s condition and this is the primary factor which is studied. Continuous data from experimental measurements across a joint allows for the determination of not only the load transfer efficiency provided parameters characterizing the pavement is known. A three-dimensional semi-analytical model was implemented for simulating the pavement response near a joint and used for interpretation and verification of the experimental data. Results show that this development is promising for the use of a rolling wheel deflectometer for rapid evaluation of joints.

Effect of Panel Size and Radius of Relative Stiffness on Critical Stresses in Concrete Pavement

Design of concrete pavements is carried out with the help of available guidelines that are generally based on single size of slab panel. However, in practice, the slab size is seen to be different than the one recommended by most of the guidelines such as PCA (Thickness design for concrete highway and street pavements, Portland Cement Assosiation, Skokie, 1984) and IRC 58 (Guidelines for the design of plain jointed rigid pavements for highways, 4th Revision, Indian Road Congress, New Delhi, 2015) , especially on curves or at the junctions. It is also established that temperature stresses vary with the plan size of the panel. The important parameter in the design of concrete pavement is critical edge stress which depends on traffic and temperature load. However, it is observed that, for the same design parameters such as traffic load and subgrade stiffness of soil, critical stress values alter largely as the panel size is diverse from the standard one. The standard panel size as specified by PCA (1984) and IRC 58 (2015) is 3.5 m $$\times $$ 4.5 m. In this paper, the effect of the size of slab panel and radius of relative stiffness on critical edge stress has been investigated. Analytical models have been developed to obtain critical edge stress for concrete pavement resting on an elastic soil foundation using finite element software. It has been found that, for smaller panel sizes with low radius of relative stiffness, critical stresses obtained are higher. Therefore, it is necessary to consider the effect of the size of slab panel and radius of relative stiffness, while designing the concrete pavement.

Concrete-Filled, Glass Fiber–Reinforced Polymer Dowels for Load Transfer in Jointed Rigid Pavements

Smooth, round steel dowels have been used for nearly a century to transfer wheel loads across concrete pavement joints. Dowels are subjected to shear and bending stresses caused by traffic loads in addition to curling stresses caused by temperature gradients in pavement slabs. Over time, the use of deicing salts corrodes steel dowels and causes damage to concrete pavement joints. Alternative dowel materials, such as stainless steel and glass fiber–reinforced polymer (GFRP), have been introduced in recent years. The dominant size of dowels for highway pavements has remained the same, typically 38 mm in diameter, and costs can be considerably higher for stainless steel compared with epoxy-coated steel dowels of the same size. Experimental tests at the University of Manitoba, Canada, examined the performance of four dowel types, including the standard 38-mm epoxy-coated steel; 38-mm solid, pultruded GFRP dowels; and 50-mm and 63.5-mm concrete-filled GFRP tube dowels. The dowels were cast in small concrete slabs of typical pavement thickness and instrumented with strain and displacement gauges. Behavior of the dowels was evaluated on the basis of measured displacements, bending strains, and performance for more than 1 million load cycles. Concrete-filled GFRP tube dowels exhibited considerably smaller displacements and, therefore, lower bearing stresses than 38-mm steel and solid GFRP bars. After 1 million load cycles, concrete-filled dowels and concrete slab showed no signs of fatigue damage or loss of load transfer, indicating a reasonable potential for replacing steel dowels, particularly in corrosive environments.

Concrete-Filled, Glass Fiber-Reinforced Polymer Dowels for Load Transfer in Jointed Rigid Pavements

Smooth, round steel dowels have been used for nearly a century to transfer wheel loads across concrete pavement joints. Dowels are subjected to shear and bending stresses caused by traffic loads in addition to curling stresses caused by temperature gradients in pavement slabs. Over time, the use of deicing salts corrodes steel dowels and causes damage to concrete pavement joints. Alternative dowel materials, such as stainless steel and glass fiber-reinforced polymer (GFRP), have been introduced in recent years. The dominant size of dowels for highway pavements has remained the same, typically 38 mm in diameter, and costs can be considerably higher for stainless steel compared with epoxy-coated steel dowels of the same size. Experimental tests at the University of Manitoba, Canada, examined the performance of four dowel types, including the standard 38-mm epoxy-coated steel; 38-mm solid, pultruded GFRP dowels; and 50-mm and 63.5-mm concrete-filled GFRP tube dowels. The dowels were cast in small concrete sl...

Performance of Rigid Pavement Rehabilitation Treatments in the Long-Term Pavement Performance SPS-6 Experiment

The results of a study conducted to assess the relative performance of different jointed rigid pavement rehabilitation treatments, including the influence of pretreatment condition and other factors, are presented. The data used in the study were drawn from the Long-Term Pavement Performance Studies' Specific Pavement Study (SPS) SPS-6 and General Pavement Study (GPS) GPS-7B experiments. The rehabilitation treatments used in the SPS-6 experiment were minimal and intensive nonoverlay repair, 4-in. asphalt overlays with minimal and intensive preoverlay preparation, 4-in. overlays with sawed and sealed joints, and 4- and 8-in. asphalt overlays of cracked and seated concrete slabs. Overall, the rigid pavement rehabilitation treatments in the SPS-6 experiment could be ranked from most to least effective in the following order: 8-in. overlay of cracked or broken and seated pavement, 4-in. overlay (of either intact or cracked or broken and seated pavement, with or without sawing and sealing of joints and with either minimal or intensive preoverlay repair), concrete pavement restoration with diamond grinding, and concrete pavement restoration without diamond grinding. Concrete pavement restoration with diamond grinding yielded an initial posttreatment international roughness index (IRI) of 1.05 m/km, on average, whereas restoration without diamond grinding yielded no benefit in IRI and in fact tended to leave the pavement rougher than before. In the long term, both restoration and overlay treatments reduced long-term roughness, rutting, and cracking levels compared with those on the control sections, but the conditions of the restored test sections are approaching those of the control sections faster than those of the overlay sections.

Stresses in Jointed Rigid Pavements

A novel application of the principles of fracture mechanics combined with multilayered elastic theory is used to obtain the design stresses midway between the transverse joints at the bottom of the longitudinal edge of rigid pavements and for corner loading of slabs without dowels. The thermal curl stresses and deflection for slabs that are curled up, with and without vehicular loading, are also determined. The basic idea is to treat a joint with no load transfer, as a crack in a continuously supported plate on an elastic foundation. The deflection and stresses caused by the joint are determined by fracture mechanics, and those for the continuous pavement are determined by the CHEVRON multilayered elastic computer program. The total deflection and stresses are then obtained by superposition. The deflection and stresses so determined are compared with the Westergaard theoretical solutions, the results of finite-element programs, and experimental data from the American Association of State Highway Officials Road Test, showing good agreement.

Joint Seal Practices in the United States: Observations and Considerations

In recent years, states have adopted a wide variety of joint sealing practices for jointed rigid pavements, based on local experience. Over time, the adoption of quality control/quality assurance practices has resulted in decreased inspection and attention that ensure compliance with good joint seal installation practices. At this time, several agencies have adopted or are considering a policy of providing for rigid pavement joints by using a single 3-mm (1/8-in.) saw cut. Agencies are either leaving this saw cut unfilled or filling it with hot-poured sealant, recognizing that it is not effectively sealed. This practice may prove acceptable where positive drainage features are naturally occurring (coarse-grained subgrade) or where climates are very hot and dry, resulting in minimal joint movement. Other agencies continue to use established joint-sealing practices with good pavement performance results. This approach continues to be a prudent one, particularly in wet climates with fine-grained subgrade materials. Here slab-support erosion has been shown to result in accelerated deterioration of jointed rigid pavements.

Mechanistic Evaluation of Rigid Airfield Pavements

A structural deterioration relationship is developed using the U.S. Army Corps of Engineers accelerated traffic tests for plain concrete airfield pavements. The relationship predicts the performance of the rigid pavement in terms of the structural condition index from the pavement's Westergaard edge stresses, flexural strength, and number of load applications. The model is compared to other design criteria and unfailed test sections and gives reasonable agreement. The relationship between the structural condition index and the coverages at initial failure of the pavement is determined, and an alternative fatigue curve is suggested for use in the thickness design of rigid airfield pavements with joints capable of load transfer. The relationships developed only account for the tensile fatigue-loading-induced deterioration of the rigid airfield pavement. Actual in-service pavements will show additional deterioration because of other jointed rigid pavement distresses such as pumping, settlement or faulting, d...

Dynamic Analysis of Rigid Airport Pavements with Discontinuities

A finite element procedure for the dynamic analysis of rigid airport pavements with discontinuities is presented. The analysis procedure considers the dynamic interaction between aircraft and a rigid pavement. The rigid pavement is modeled as a series of discontinuous, thin‐plate finite elements resting on a viscoelastic foundation. At the discontinuities, the load transfer devices are modeled as vertical springs, the stiffness of which depends on the dowel properties and the dowel‐concrete interaction. The viscoelastic foundation is modeled by distributed springs and dashpots. The moving aircraft loads are represented by masses supported by linear spring and dashpot systems, which have specified horizontal velocities and accelerations. Numerical results obtained from the analytical formulation presented are compared with available analytical solutions and experimental data. A parametric study is conducted to determine the effects of the various parameters on the dynamic response of jointed rigid pavement...