<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>THE ONTARIO ON BOARD WEIGHING DEMONSTRATION PROJECT</title>
      <link>https://trid.trb.org/View/301232</link>
      <description><![CDATA[The ability for highway truck operators to monitor the actual loads on a vehicle during the loading operation can be of great economic benefit.  While systems to provide on board axle weights have been developed in the past, the systems suffered from two main problems: accuracy under varying conditions, and reliability when operating conditions are harsh.  This paper describes an on board weighing project sponsored by the Ontario Ministry of Transportation.  Single semi trailer units were instrumented with shear sensors connected to the three axles in a tridem set.  The data collection system was mounted within the protection of the I-Beam section. Separate readout units are located in the cab of the truck tractor, and in the cab of the loader unit.  Preliminary results indicate that under both level and rough road conditions, the on board weight measurements were within 1% of the static scale weights. Further accuracy testing of the system is planned.  For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/301232</guid>
    </item>
    <item>
      <title>ASPHALT TECHNOLOGY FOR IN-PLACE SURFACE RECYCLING HEAT REFORMING PROCESS</title>
      <link>https://trid.trb.org/View/301233</link>
      <description><![CDATA[The heat reforming process described in this paper consists of two main elements: a heating system (two lpg infrared preheaters) capable of effectively heating to a depth of 50 mm, and a reforming system which can readily improve the pavement quality through rejuvenation and/or place a new surface course of up to 50 mm thickness in one pass. Successful application of the heat reforming process requires the following stages: 1) determining the overall suitability of the aged, cracked or rutted pavement for processing, 2) testing the existing pavement to determine the necessary rejuvenator application rate, and 3) monitoring the quality of the in-place, hot recycled mix and any new mix during and after processing, including surface tolerance.  This paper summarizes the author's experience with the process and typical results.  For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/301233</guid>
    </item>
    <item>
      <title>A TEST FILL FOR GEOGRID REINFORCEMENT OF COHESIVE SOILS</title>
      <link>https://trid.trb.org/View/301234</link>
      <description><![CDATA[A geogrid reinforced cohesive soil test embankment 12 metres high with 1:1 side slopes is under construction in the province of Alberta.  Three different types of geogrids are being evaluated at the site, including tensar SR2, signode tnx-5001, and paragrid 50s.  This paper outlines the geometric layout for the test fill and the design methods currently used for this type of reinforced slope. Instrumentation has been installed to monitor pore pressure responses and the deformations of both the in situ foundation soils and the compacted fill material.  Through the analysis of the soil-geogrid interaction performance, a rational design approach will be developed for high geogrid reinforced slopes constructed with cohesive soils.  For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/301234</guid>
    </item>
    <item>
      <title>SLOW SPEED WEIGH IN MOTION FOR ENFORCEMENT</title>
      <link>https://trid.trb.org/View/301235</link>
      <description><![CDATA[Slow speed weigh in motion (wim) offers an alternative to the traditional methods of vehicle weight enforcement. While slow speed wim has been used with good success in Europe in the past few years, it has not been implemented extensively in North America due to accuracy requirements. With increased emphasis on the enforcement of weight and dimension regulations, there is a need to change highway agency policy in order to take advantage of new technology. The changes may include Federal and provincial mandates which broaden the tolerances of equipment used to enforce weight and dimension regulations.  This paper presents a description of slow speed wim technology, and a discussion of what the technology can offer.  Special attention is given to the possibility of remote operation slow speed wim sites.  The paper also describes a demonstration project underway in the province of Saskatchewan.  For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/301235</guid>
    </item>
    <item>
      <title>CENTRAL ARTERY / THIRD HARBOR TUNNEL PROJECT</title>
      <link>https://trid.trb.org/View/301236</link>
      <description><![CDATA[Boston's i-93 central artery has been considered one of the most congested and dangerous sections of interstate highway in the country.  In December 1985, the Federal highway administration approved a plan to address the problem, with two major components: 1) building a new eight to ten lane central artery, mostly underground, between the I-90 Massachusetts turnpike and charlestown; 2) the extension of the i-90 turnpike to logan airport via a seaport access road passing through commercial land in South Boston and a four-lane tunnel across Boston harbour.  This paper briefly describes the planned project under the following headings: construction management, utility relocation, and materials disposal.  For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/301236</guid>
    </item>
    <item>
      <title>D-CRACKING STUDIES OF SOME MANITOBA AGGREGATES</title>
      <link>https://trid.trb.org/View/302868</link>
      <description><![CDATA[A field study of concrete pavements in Manitoba in 1983 revealed a high incidence of d-cracking.  Further testing revealed that the cracking was caused by aggregates which were susceptible to deterioration when the maximum size was 40 mm.  Reducing the aggregate top size to a maximum of 20 mm could provide a solution to the d-cracking problem, but would result in higher costs due to the additional aggregate processing required and higher cement content required. This study was undertaken to determine whether some of these costs could be offset by substituting some of the cement with flyash.  Results of testing using the ASTM c-666 method b freeze-thaw test indicated that substitution of 20% of the cement by class f flyash led to d-cracking, in spite of yielding concrete with lower slump and higher strength.  A study of the effect of air entrainment on d-cracking indicated that an air content of 8.5% prevented d-cracking from occurring whereas air contents of 1.9% and 5.0% did not.  For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/302868</guid>
    </item>
    <item>
      <title>PORE STRUCTURE ANALYSES OF AGGREGATES SUSCEPTIBLE TO D-CRACKING</title>
      <link>https://trid.trb.org/View/302869</link>
      <description><![CDATA[D-cracking of concrete pavement is attributed to freeze-thaw deterioration of certain coarse carbonate aggregates in the concrete.  It is generally accepted that pore structure of the aggregate plays a very important role in d-cracking: the volume of pores, their surface area, the pore size, shape and distribution, and the spatial distribution.  The purpose of this study was to apply various techniques of pore structure analysis to the study of carbonate rock aggregates susceptible to d-cracking. Geotechnical and geological test methods were employed, as well as laboratory investigations. Results indicate that 1) total optical porosity (top) ranged from 15.1% to 23.4% for the non-durable specimens and from 5.2% to 22.4% for the durable specimens; 2) non-durable specimens exhibited narrower pore-size ranges that those of durable specimens; 3) non-durable specimens has a higher percentage of 1 e/d pore porosity; 4) correlations of the pore and roughness porosity to d-cracking susceptibility were inconclusive. For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/302869</guid>
    </item>
    <item>
      <title>DEVELOPMENT OF AN UNCONFINED FREEZE-THAW TEST FOR COARSE AGGREGATES</title>
      <link>https://trid.trb.org/View/302870</link>
      <description><![CDATA[The test method described in this paper consists of saturating a graded sample of aggregate in a 3% sodium chloride solution for 24 hours.  The sample is then drained and submitted to five cycles of freezing at -18 c and thawing at room temperature.  The sample is then washed, oven-dried, and regraded on the original sieves.  The amount passing each sieve is expressed as a percent loss by mass of the original mass.  The within-laboratory and multilaboratory precision of this test is significantly better than that of the magnesium sulphate soundness test. For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/302870</guid>
    </item>
    <item>
      <title>EVALUATION OF TRAFFIC AND ENVIRONMENTAL DETERIORATION OF SASKATCHEWAN PAVEMENTS</title>
      <link>https://trid.trb.org/View/302871</link>
      <description><![CDATA[A comprehensive set of pavement performance models has been developed for the province of saskatchewan's pavement management information system using the world bank's highway design and maintenance standards (hdm3) model. Based on pavement mechanics, the hdm3 model relates increases in pavement roughness to structural strength and traffic as well as surface condition and environmental factors.  396 km of asphalt pavements were analyzed using the hdm3 method. Adjcent lanes which had appreciably different axle loadings were examined to exclude the environmental effects. Predictions for traffic loading effects were realistic and the strength-related term contributed little to the total roughness changes observed.  The rutting term, which itself depends on axle loading and structural number, accounts for some of the load-associated roughness deterioration.  The environmental term was found to account for the majority of the observed roughness changes.  For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/302871</guid>
    </item>
    <item>
      <title>ELASTOSTATIC ANALYSIS AND BACKCALCULATION ESTIMATES OF PAVEMENT LAYER MODULI</title>
      <link>https://trid.trb.org/View/302872</link>
      <description><![CDATA[Although the backcalculation of layer moduli from nondestructive testing data has received considerable attention over the last ten years, serious questions regarding the interpretation of backcalculation results still remain.  This paper reviews some of the background on the development of multilayer elastostatic analysis of pavement structures and takes a critical look at the limitations of backcalculation routines which utilize elastostatic models.  Examples are presented which demonstrate problems associated with backcalculation and recommendations are made for evaluation of pavement performance parameters and interpretation of nondestructive test data.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/302872</guid>
    </item>
    <item>
      <title>NON-DESTRUCTIVE TESTING : INTERPRETATION OF DEFLECTION BOWL FOR FALLING WEIGHT DEFLECTOMETER TESTS ON FLEXIBLE PAVEMENTS</title>
      <link>https://trid.trb.org/View/302873</link>
      <description><![CDATA[Non-destructive testing of pavement structures can be achieved by accurately measuring and interpreting deflection data.  This paper describes a computer program designed for simple and fast processing of deflection data collected using a falling weight deflectometer (fwd).  A set of diagnostic parameters are calculated: first, maximum horizontal strain in the asphalt concrete (ac) under the test load, directly via the corresponding maximum curvature; next, the elastic stiffness (or Young's modulus) of the subgrade; and finally, the vertical stress, strain and deflection on top of the subgrade, by means of an improved method of equivalent layer thickness.  The actual stresses, strains, and deflections at test conditions can be normalized for standard ac temperature and standard test load.  Diagnostic and design applications are discussed. Comparisons are made with parallel elastic layer analysis computations.  (a)]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/302873</guid>
    </item>
    <item>
      <title>MITIGATION OF INSTABILITY ASPHALT PAVEMENT RUTTING</title>
      <link>https://trid.trb.org/View/302874</link>
      <description><![CDATA[Ten sites in the town of lethbridge, Alberta that exhibited modest to severe pavement rutting were identified for examination.  Core samples were obtained and panels across the traffic lane removed.  At all locations, rutting had developed primarily within the asphaltic concrete layer itself, not in the base course or subgrade.  Laboratory tests on the samples examined in situ density, asphalt content, Marshall characteristics, penetration and viscosity tests.  The feasibility of using a harder asphalt cement was examined and alternative mix designs were assessed by Marshall stability, hveem stabilometer, repeated load triaxial and creep test methods.  On the basis of the lab program, improved concrete mixes were identified that would extend the life of pavements with respect to instability rutting.  For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/302874</guid>
    </item>
    <item>
      <title>ASPHALT CONCRETE RUTTING AND ITS MITIGATION</title>
      <link>https://trid.trb.org/View/302875</link>
      <description><![CDATA[Rutting has become a common and costly maintenance problem in metropolitan Toronto, particularly of bus bay and curb lane composite pavements.  The asphalt mix factors contributing to rutting are typically a pronounced fine aggregate 'hump' in the grading curve, developed using natural, rounded blend sands, and low in-place air voids (less than 2%) with the coarse aggregate 'floating' in the fine aggregate/asphalt cement matrix.  Rutting can generally be attributed to three factors: environment, traffic and materials.  Given that the pavement engineer has little control over the environment or traffic levels, action to mitigate rutting has focused on the quality of the binder course.  The use of manufactured sands (crushed angular sands or steel slag fine aggregate) in high stability binder course mixes with adequate air voids is recommended.  Close compaction control is also required to ensure high stabilities in the field.  For the covering abstract of the conference see IRRD 807201.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/302875</guid>
    </item>
    <item>
      <title>UPGRADING TRANSITIONS FROM APPROACH GUARDRAILS TO BRIDGE RAILS</title>
      <link>https://trid.trb.org/View/302876</link>
      <description><![CDATA[Over one-half of 350 bridge-related fatal accidents in 1975 involved a collision with the end of a bridge rail.  In some of these cases there was no approach guardrail.  In other cases, the transition between the guardrail and the bridge rail deflected too much and allowed the vehicle to strike the bridge end.  Until recently, only a few crash tests had been conducted on guardrail to bridge rail transitions.  A series of transition designs have been developed and tested that are significantly safer than many of the current standards.  These improved designs are now being installed and should be in widespread use in the next few years.  This paper presents detailed drawings of several designs, and briefly discusses the construction and maintenance considerations.]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/302876</guid>
    </item>
    <item>
      <title>CONSTRUCTION THROUGH DELICATE ECOSYSTEMS</title>
      <link>https://trid.trb.org/View/302877</link>
      <description><![CDATA[In 1984, the Nova Scotia government proposed to build a section of provincial highway 107 across a salt marsh at chezzetcook.  Salt marshes were identified by several agencies as being sensitive to any construction, especially a roadway which would have the potential of even greater effects from deicing chemicals or accidental spills.  The department established a series of testing procedures which would be used to judge the effects of the construction. Parameters to be measured included water chemistry, chlorophyll, bacteria, vegetation, benthos, fish, clams, birds, foraminifera and sedimentology.  In order to protect the salt marsh, extraordinary construction techniques had to be implemented to reduce siltation at any other injurious site.  Special lagoons were constructed to collect any runoff and the entire construction site was protected by silt fences.  Department technicians continuously monitored water chemistry, expecially the ph of runoff waters. Detailed monitoring of the suspended solids in all runoff waters was done using a special sampling device, the van dorn sampler.  (a)]]></description>
      <pubDate>Sat, 30 Sep 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/302877</guid>
    </item>
  </channel>
</rss>