<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
    <description></description>
    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
    </image>
    <item>
      <title>Influence of high content of reclaimed asphalt on the mechanical properties of cement-treated base under critical environmental conditions</title>
      <link>https://trid.trb.org/View/1639937</link>
      <description><![CDATA[The influence of reclaimed asphalt pavement (RAP) on the mechanical properties of cement-treated materials (CTMs) has not been completely understood, while its usage as a partial supplement of virgin aggregates in road layers has been investigated by many researchers for its eco-friendly aspects. In addition, CTMs containing high contents of RAP have not yet been widely applied. Therefore, this paper aimed to experimentally investigate cement-treated base mixtures containing high percentages of RAP in terms of mechanical properties in different environmental conditions to find a proper opportunity to increase the recycling rate of this valuable material. In this regard, mixture design formulation was determined based on modified effort compaction test results as well as unconfined compressive strength and indirect tensile strength tests of seven-days cured samples. Also, critical condition of hot summer and wet winter circumstances were taken into account as prepared cylinder samples were dry-cured under 50 °C and wet-cured under 25 °C, respectively. Results indicate that incorporation of RAP materials increases optimum moisture content (OMC), and therefore, reduces maximum dry density (MDD). Additionally, it is found that temperature of 50 °C in RAP incorporated mixes and moisture in control mixes are critical conditions for determining strengths and finally, structural design of pavement.]]></description>
      <pubDate>Tue, 30 Jul 2019 15:56:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/1639937</guid>
    </item>
    <item>
      <title>Plate Load Testing on Layered Pavement Foundation System to Characterize Mechanistic Parameters</title>
      <link>https://trid.trb.org/View/1594089</link>
      <description><![CDATA[This paper presents a field case study of in situ automated plate load testing (APLT) to evaluate the mechanistic properties of two foundation layer test sections constructed on Illinois Tollway pavement research test sections. One section consisted of nominal 102 mm thick aggregate subbase underlain by nominal 254 mm thick lime stabilized subgrade (LSS) over natural subgrade. The other section consisted of nominal 102 mm thick aggregate subbase over compacted subgrade. The foundation layers were designed to support a cement treated base (CTB) layer and continuously reinforced concrete pavement (CRCP). Testing was conducted to determine in situ composite resilient modulus (Mr) on top of the aggregate subbase layer, the individual layer Mr values, modulus of subgrade reaction (k) values on unstabilized and LSS layers, and permanent deformation (dp) characteristics on the aggregate subbase and subgrade layers. Results show that the pavement foundation conditions were highly variable within and between test sections [coefficient of variation (COV) values ranged between 39% to 63%]. Permanent deformation models were developed to estimate deformations under future trafficking. Stress-dependent universal Mr model parameter values were developed for comparison to typical laboratory Mr values. Falling weight deflectometer (FWD) testing was conducted after the pavement was constructed, and the backcalculated results suggest that the variability of the foundation layers is dampened by the stiffer CRCP and CTB structure.]]></description>
      <pubDate>Wed, 24 Apr 2019 09:26:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1594089</guid>
    </item>
    <item>
      <title>Inverted base pavements: construction and performance</title>
      <link>https://trid.trb.org/View/1599320</link>
      <description><![CDATA[Inverted base pavements involve a well-compacted granular aggregate base built between a thin asphalt concrete layer and a cement-treated base. Inverted base pavements can be constructed using conventional equipment and procedures but require proper quality control. This study reviews the extensive South African experience and case histories in the USA. Accumulating evidence suggests that inverted base pavements are a viable alternative and can outperform conventional pavements at a lower cost. Inverted base pavements rely on the complementary interaction between layers. The cement-treated base provides a stiff foundation for efficient compaction and constrains the deformation of the stress-sensitive granular aggregate base. The thin asphalt surface layer deforms as a membrane and develops low tensile stress. Additional large-scale field tests should be conducted to assess the performance of inverted base pavement designs in a wide range of conditions relevant to the USA.]]></description>
      <pubDate>Mon, 22 Apr 2019 13:06:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/1599320</guid>
    </item>
    <item>
      <title>Meso-scale Finite Element Model of Crack Propagation in Cement Treated Base Materials</title>
      <link>https://trid.trb.org/View/1572566</link>
      <description><![CDATA[Cement Treated Base (CTB) pavement has been widely used at different climatic regions all over the world, and could stay for a life-long period when the stress level remained controlled under the fatigue limit. Although much attention had been paid to the study of macroscopic performance of CTB in the prior research, the mesoscale study of this highly heterogeneous quasi-brittle material is rather limited. In this paper, a two-dimensional (2D) mesoscale crack propagation model of CTB assumed as a three-phase material composed of aggregate, cement mortar and interface transitional zones (ITZ) was developed through Finite Element method (FEM) with cohesive elements. Digital image processing (DIP) methods and vectorization processing were utilized to create a 2D heterogeneous numerical fracture model using the digital image obtained through scanning. The zero-thickness cohesive elements with traction-separation laws were inserted into both the cement mortar and the aggregate–cement interfaces to simulate the potential micro-crack in cohesive zone model (CZM) with the help of a MATLAB program. The load-displacement curves and the fracture patterns of the model were obtained, and the tensile strength was calculated, which were compared with the result of the laboratory test. The load-displacement curves, crack geometry, and tensile strength were proved to be a satisfactory agreement between FE analyses and experimental test. Different cohesive parameters were assigned to the crack propagation FE models to study mesoscale material properties, which provides an effective way to study mesoscale parameters.]]></description>
      <pubDate>Sat, 02 Mar 2019 15:41:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1572566</guid>
    </item>
    <item>
      <title>Early-Age Fatigue Damage Assessment of Cement-Treated Bases under Repetitive Heavy Traffic Loading</title>
      <link>https://trid.trb.org/View/1505450</link>
      <description><![CDATA[This paper aims to develop measures to minimize the early-age fatigue damage of prematurely opened cement-treated bases (CTBs) due to repetitive heavy traffic loading. The four-point bending test was used in this study to characterize the early-age fatigue performance as well as the flexural properties of two different locally sourced granular materials stabilized with 3% general purpose (GP) cement. All the flexural tests were executed under stress-controlled mode. The fatigue test results evinced the existence of an endurance limit in cemented granular materials (CGMs) even at 7 days curing age. A stress-based fatigue performance model was developed for predicting the early-age fatigue performance of CGMs in service. In addition, the 7-day fatigue test data from this study were validated using existing CGM fatigue models. The numerical results obtained from the CIRCLY program indicated that the level of interaction between the axles of an axle configuration decreases with decreasing CTB layer thickness, resulting in increased pavement fatigue damage. It was also found that the asphalt cover over CTB required to prevent the occurrence of initial fatigue damage to the CTB decreases with increasing CTB modulus, subgrade strength, and CTB layer thickness. The limitations and simplifications in current pavement design and testing methods are also critically discussed and addressed on the basis of the results of this study.]]></description>
      <pubDate>Tue, 29 May 2018 16:04:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1505450</guid>
    </item>
    <item>
      <title>Alternative Laboratory Test Method and Correlations to Estimate Modulus of Rupture of Cement-Treated Base Materials</title>
      <link>https://trid.trb.org/View/1437925</link>
      <description><![CDATA[Chemically stabilized base and soil layers including cement-treated aggregates are widely used to provide long-term support for pavement structures on the Texas highways. This is more prevalent especially with the recent surge in the heavy truck-traffic loading in the energy-sector impacted areas of south-central Texas. With the use of stabilized layers however, accurate characterization of the load-associated fatigue behavior in the pavement structure, quite often, becomes a complicated technical issue. The primary input required in the mechanistic-empirical (M-E) design procedures to predict the fatigue cracking in stabilized layers is the 28-day flexural strength (or Modulus of Rupture, MoR). The AASHTO Mechanistic Empirical Pavement Design Guide (MEPDG) and the Portland Cement Association (PCA) recommend using the 7-day Unconfined Compressive Strength (UCS) to estimate the MoR for input Level 2 analysis. This paper presents an experimental study to evaluate MoR-UCS relationships and develops a new predictive model to improve the estimation of MoR using three standard Texas base materials, treated with three cement contents (2, 3, and 4%). Also, a new test method based on the indirect tensile (IDT) strength test was proposed to reduce test materials and resources required to run the MoR and UCS tests. New MoR-UCS relationship model developed in the study exhibited improved estimation of the MoR values. As well, the strong correlation between MoR and tensile strength obtained from newly formulated IDT test method indicated the possibility of estimating MoR required to predict the fatigue life of cement-treated base materials for the M-E design procedures.]]></description>
      <pubDate>Mon, 23 Jan 2017 16:05:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1437925</guid>
    </item>
    <item>
      <title>Cement Treated RAP Mixes for Roadway Bases</title>
      <link>https://trid.trb.org/View/1428769</link>
      <description><![CDATA[Reclaimed asphalt pavement (RAP) and granular base materials were collected from stockpiles in six Texas Department of Transportation (TxDOT) districts to evaluate the feasibility of using high RAP content mixes for base course applications. Mixes containing 100%, 75% and 50% RAP treated with Portland cement of 0%, 2%, 4% and 6% were evaluated in a full-factorial laboratory experiment. For mixes of 75% and 50% RAP, both virgin and salvage base materials, when available, were used. Experimental results indicate that, besides the cement content, the RAP content and fines content in RAP-granular base mixes significantly affect the properties of the RAP mixes, and that the effects of RAP type and asphalt content are very limited. To achieve a 300-psi unconfined compressive strength as required by TxDOT for cement-treated bases, the optimum cement contents are statistically about 4%, 3% and 2% for mixes with 100%, 75% and 50% RAP, respectively. Since the achievement of any specified strength and/or modulus may not always ensure the long-term durability of RAP mixes, a number of other parameters were also evaluated through laboratory testing. These parameters are necessary for a comprehensive evaluation of various mixes containing high RAP contents (50% or more). Based on the experimental results, guidelines for laboratory testing and mix design process of RAP mixes are provided with field verification data collected from actual construction projects.]]></description>
      <pubDate>Wed, 09 Nov 2016 13:24:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1428769</guid>
    </item>
    <item>
      <title>Daily and Seasonal Variation of Several Parameters Based on the Measured Deflection at the Edges of Different Types of Semi-rigid Pavements Transverse Cracks</title>
      <link>https://trid.trb.org/View/1414159</link>
      <description><![CDATA[There are around 30% semi-rigid pavements in the National Spanish Roads Network, being a composition of bituminous layers over cement treated layers. Those with more than 20 years in service were constructed with a high percentage of cement. As a result, thermal transverse cracks were reflected on the wearing course, which have to be sealed and reinforced periodically.  This research is focused on transverse cracks edges daily and seasonal variation of Load Transfer (LT, %), Relative Deflection (RD, micrometer/micrometer) and Maximum Deflection (MD, micrometer), of four types of situations: thin cracks (width < 5 mm); wide cracks (width ≥ 5 mm); block cracks and fatigue cracks on the wheel-paths. For this purpose, eight sections of roads were chosen from thermal zones hot in summer and little rainy but cold in winter. The findings of this study have been the quantification of the transverse cracks pavement structural state in two scenarios referred to as winter and summer conditions. Firstly, it was proved that the before mentioned structural parameters correlated with temperature. Secondly, these parameters' daily and seasonal variations were defined. The main findings of this research are: (1) MD in semi-rigid pavements is even less than 200 micrometer after more than 20 years in service. Thus, LT and RD turn out to be the main structural parameters to evaluate pavement bearing capacity close to thermal transverse cracks; (2) LT rises with temperature reaching 100% whereas RD decreases reaching almost 1 micrometer/micrometer, as well as, MD goes down up to the temperature turning point in which the bituminous layers influence is higher; (3) After more than 20 years in service, semi-rigid pavement road stretches could show good pavement structural state (that is, LT > 80%) measuring at any time in summer condition (average temperature 5 cm below the surface ≥ 20 °C); (4) Crack sides MD measured with pavement temperature close to 20 °C (reference temperature for Spanish standardized deflections) in winter condition (average temperature 5 cm below the surface < 20 °C), could also show a good pavement structural state, MD < 300 micrometer; (5) If the worst structural pavement state needs to be evaluated, deflections should be measured on the front side cracks except for block shape cracks in winter condition and thinner cracks in both conditions; (6) Wide cracks LT experiences the greatest daily variation range among all crack types, from more than 20% to more than 30% in winter condition and thin cracks unseat them in summer condition with a daily variation range from almost 10% to less than 20%; and (7) Besides, wide cracks RD daily variation is the highest among all crack types in both conditions, ranging from a decrease of more than 0.30 micrometer/micrometer to more than 0.60 micrometer/micrometer in winter condition and half this range of values in summer condition.]]></description>
      <pubDate>Wed, 24 Aug 2016 16:53:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1414159</guid>
    </item>
    <item>
      <title>Investigation of Performance Requirements of Full Depth Reclamation Stabilization</title>
      <link>https://trid.trb.org/View/1409676</link>
      <description><![CDATA[The Minnesota Department of Transportation (MnDOT) recognizes the value of stabilized full-depth reclamation (SFDR) recycling practices and wishes to promote further use of SFDR in its state. Before widespread application of SFDR is attainable, it is imperative that the performance requirements for SFDR be determined. Since there is an absence of such a specification in Minnesota, the structural capacity of SFDR may not be fully attained. The objective of this research project is to determine optimal properties that SFDR material should attain to be used as a base layer for hot-mix asphalt (HMA) roadways. Optimum SFDR material properties are achieved when rutting and low temperature cracking is minimized. The stabilizing materials used to achieve these parameters are to be determined by the agency that is investigating a specific SFDR project. SFDR is used to correct structural deficiencies in pavement; these deficiencies include deep rutting, load-associated cracks, thermal cracks, reflection cracks, and maintenance patches such as spray, skin, potholes, and deep hot mix. SFDR can correct inconsistencies in the subgrade base as well as the asphalt layers.]]></description>
      <pubDate>Wed, 08 Jun 2016 14:55:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1409676</guid>
    </item>
    <item>
      <title>Analysis of inverted base pavements with thin-asphalt layers</title>
      <link>https://trid.trb.org/View/1401189</link>
      <description><![CDATA[Inverted base pavements are flexible pavement structures built by placing a top quality compacted granular aggregate base between a rigid cement-treated base and a thin-asphalt surface layer. The proximity of the granular base to the load makes its behaviour critical to the pavement response. Three-dimensional finite-element simulations are conducted to assess the mechanical performance of different inverted base pavement structures, with emphasis placed on pavements that feature thin-asphalt surface layers. A nonlinear constitutive model captures the anisotropic stress-dependent stiffness of the granular base. Results show that the stress distribution within inverted base pavements is markedly different from that of conventional pavements due to the stiffness contrast between successive layers. Thin-asphalt layers deform more uniformly and experience lower tension than thick layers. However, in the presence of combined shear and vertical contact loads, the benefits of a membrane response in thin asphalt concrete layers may be overwhelmed by the increased tensile strain at the load edge. The transition from beam to membrane asphalt response depends on the relative stiffness between the asphalt layer and the aggregate base. In most cases, the transition takes place at an asphalt layer thickness between 25 mm and 50 mm.]]></description>
      <pubDate>Wed, 20 Apr 2016 14:42:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1401189</guid>
    </item>
    <item>
      <title>Design and Construction of Long-Life Semirigid Pavement: Investigation from Test Sections in Northern and Southern China</title>
      <link>https://trid.trb.org/View/1392698</link>
      <description><![CDATA[Semi-rigid pavement, pavement with rigid cement treated base layer and flexible asphalt surface, is the primary pavement structure in China. Compared to long-life flexible pavement commonly used in US and Europe, long-life semi-rigid pavements are more suitable in China currently with heavy truck loading. Semi-rigid pavements are relatively low cost but would increase the risk of reflection cracking. Nevertheless, an investigation conducted in 2011 through 2014 preliminarily proved that well designed and constructed semi-rigid pavements can also reach the standards of long-life pavements. Based on nearly 30 years of experiences in freeway constructions in China, the design strategy and new construction techniques of long-life semi-rigid pavements were summarized in this paper. To verify the applicability of the proposed strategy and techniques, two test sections were constructed in 2012; one was located in the Northern China and the other in the Southern China. Intensive tests and inspections were conducted during construction, and field surveys were performed several times after construction. Investigation found that although these two sections have almost the same structure and the same construction techniques, there are huge performance differences between them. The transverse cracking spacing is 47.9 m/1000 m² for North section and 0.75 m/1000 m² for the other. On the bases of comprehensive analysis, the causes of cracking were found and the lessons were learned that: 1) The cracks in North section were caused by frost and had initiated in the compacted subgrade and then propagated to the surface. 2) The proposed design strategy and construction techniques have excellent effectiveness to delay or inhibit the occurrence of reflection cracking, increase structural capacity, and improve the construction uniformity.]]></description>
      <pubDate>Sun, 31 Jan 2016 17:49:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1392698</guid>
    </item>
    <item>
      <title>Impact of the implementation of continuous construction method on pavement cracking performance</title>
      <link>https://trid.trb.org/View/1377493</link>
      <description><![CDATA[A continuous construction method (CCM) was proposed to decrease the reflective cracking generated from the cement-treated macadam base by reducing the shrinkage of base materials and improving the bond strength at the interface between the base layer and surface layer. Traditional 3–7 days of curing period of cement-treated macadam base was eliminated by CCM and the asphalt mixture can be paved immediately after the construction of cement-treated macadam base. An anti-cracking agent was developed and added into the cement-treated base materials to prolong the hydration process and improve the shrinkage performance of base materials. The influences of anti-cracking agent on the properties of cement-treated materials were analysed using laboratory tests. The generation of micro-expansion ettringite from cement system was investigated from the microscopic perspective using the scanning electronic microscope test. Test roads were constructed and contrasted to demonstrate the feasibility of this approach and showed a superior anti-cracking performance.]]></description>
      <pubDate>Sun, 03 Jan 2016 16:36:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1377493</guid>
    </item>
    <item>
      <title>Pavement Testing and Analysis of Heavy Hauls for SR 12</title>
      <link>https://trid.trb.org/View/1374096</link>
      <description><![CDATA[The pavement structure of SR 12 between Montesano and Elma, Washington was evaluated for the proposed heavy loads associated with construction of the Satsop power plant. Information used in evaluating SR 12 resulted from two sources which included field studies conducted by the Washington State Department of Transportation and development of various material strength parameters by the University of Washington. These data were used to model the pavement structure as a layered elastic system. By use of this analysis procedure, the stresses, strains and deflections were estimated for the expected range of loading conditions. The results indicate that the most probable amount of damage (fatigue and rutting) expected for the non-cement treated base structural sections is less than one to two percent of available pavement life for the "expected" loading condition. An increase in either or both the trailer wheel load and pavement temperature will act to produce greater losses in pavement life. It is estimated that the tensile stresses in the cement treated base may exceed the tensile strength of this material.]]></description>
      <pubDate>Sat, 21 Nov 2015 17:31:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/1374096</guid>
    </item>
    <item>
      <title>Pavement Research at the Washington State University Test Track Volume One, Experimental Ring No. 1: A Study of Cement Treated and Asphaltic Treated Bases</title>
      <link>https://trid.trb.org/View/1372772</link>
      <description><![CDATA[Using full-scale construction equipment and truck loadings on a circular track of 260 ft circumference, evaluation of various base thicknesses and types has been accomplished in this first of a series of tests. Fractured and non-fractured aggregate, treated and untreated bases, asphaltic and portland cement type bases are used. Results of the first ring indicate types of failure under varied environmental conditions with pavement systems subjected to millions of load applications. Difficulties in determining comparative equivalencies are discussed. Instrumentation used and possibilities for future use in rational design are reported.]]></description>
      <pubDate>Mon, 02 Nov 2015 15:17:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/1372772</guid>
    </item>
    <item>
      <title>Effect of Distresses on Deflection Basins and Backcalculation Modulus of Asphalt Pavement with Cement-Treated Base</title>
      <link>https://trid.trb.org/View/1366086</link>
      <description><![CDATA[The Falling Weight Deflectometer (FWD) is widely used to evaluate the asphalt pavement structural conditions through the deflection basin and the backcalculation modulus. The FWD test has sometimes been performed on asphalt pavement with distresses. It is necessary to investigate the effect of the distresses on the deflection basin and the backcalculation modulus. In this study, the finite element method (FEM) was used to simulate the asphalt pavement with and without the distresses and the FWD load, and thus produce the defection data. The modulus of the structural layers and subgrade was backcalculated from the FWD data using the MODULUS 6.0 program. Then the effect of the distresses was investigated on the deflection basin and the backcalculation modulus. The results indicate that the cracking and cement-treated base crushing in the asphalt pavement may result in an abnormal deflection basin and make the backcalculated modulus incorrect; therefore, it may be necessary to remove the unusual deflection basin before the backcalculation to obtain accepted backcalculation results, or decrease the number of structural layers to reduce the unreasonable backcalculation results.]]></description>
      <pubDate>Sat, 29 Aug 2015 16:08:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/1366086</guid>
    </item>
  </channel>
</rss>