bluuebunny/crossref_metadata_2025 huggingface dataset:
Large-Scale Airfield Concrete Slab Fatigue Tests
Authors: Roesler Jeffrey R. , Hiller Jacob E. , Littleton Paul C.
Published: January 2025

Large-scale concrete slab tests were conducted in the laboratory to evaluate the effect of multiple wheel gears on the fatigue resistance of concrete slabs. Monotonic and cyclic loading was completed on sixteen fully-supported slabs. The monotonic testing characterized the flexural strength of the concrete slab under the fullysupported conditions relative to the standard simply-supported flexural beam test. The testing program addressed the effects of peak stress ratio, stress range, and stress pulse type on the fatigue resistance of concrete slabs. For low cycle fatigue, stress range was not a significant factor while the applied peak stress controlled the number of repetitions to failure. For high cycle fatigue, peak stress and stress range affected the number of cycles to failure. An S-N curve analyses of the fatigue results showed that the number of repetitions to failure for the tridem pulses was not equivalent to the single pulse repetitions to failure for the same pulse duration, peak stress, and stress range.
Prediction of Top-Down Transverse Cracking in Jointed Plain Concrete Pavement
Authors: Peng Yanfei , Hansen Will , Smiley David L. , Jensen Elin A.
Published: January 2025

This paper describes the findings of a recently completed investigation by the University of Michigan to identify the causes for premature, mid-slab cracking of joined plain concrete pavement (JPCP) in Michigan. The study found several factors are working interactively to induce slab cracking. The major factor is the support characteristics of the unbound open-graded aggregate base. Deflection testing showed a permanent loss of slab contact with the base (void) exists near the doweled joint. Time history analysis of the deflection data showed that the dowels are very likely loose. Loss of slab-base contact without pumping suggests that post-compaction under heavy vehicle loading or particle degradation is occurring. In addition, the study found that the load transfer efficiency (LTE) across joints has declined since construction. Finite element analysis (ABAQUS) was used to evaluate the extent and significance of these factors on tensile stress and fatigue cracking. Fatigue failure culminates from excessive tensile stress at mid-slab at the slab’s topside outer edge. The slab stress predictions correlate well with the deflection-based fatigue model by Wu et al. (1993) suggesting that a threshold corner deflection criteria may be used to determine when loss of slab support is critical.
Québec’s Experience with Smoothness Specifications on Concrete Pavements
Authors: Thébeau Denis , Delisle Marie-Christine , Cormier Bertrand
Published: January 2025

Smoothness is one of the most important characteristics of pavement because it directly affects the traveling public. Furthermore, the initial smoothness reflects the quality of construction and is an essential condition for the pavement’s future performance. The Québec Ministry of Transportation (MTQ) has been using smoothness specifications for all concrete pavement projects since the early 1990s. The Profile Ride Index (PRI) was replaced in 1998 by the International Roughness Index (IRI) so the same specifications would apply for concrete and asphalt pavements. IRI specifications stated that profile measurements be made with a truck-mounted inertial profiler after the work is finished. Today, some contractors are still using the profilograph for control purposes during construction and there has been an increase in diamond grinded surface area, up to 32% on some projects. A study was undertaken in 2000 to assess different kinds of roughness measuring equipment (profilograph, Disptick©, lightweight inertial profiler, rolling profiler and 2 types of truck-mounted inertial profiler) and determine those that would be best suited for construction control. This study concluded that the rolling profiler was the best equipment for this purpose. In 2003, MTQ experimented with modified specifications requiring that roughness measurements be made using a rolling profiler and forbidding any surface correction before the measurements were made. The main benefits of this method were that MTQ could check the 100-metre control lots soon after they were built instead of waiting until the end of the work and the contractors could also use the results for own quality control.
Roller-Compacted Concrete Pavement, An Industry Perspective
Authors: Wentland Kevin A.
Published: January 2025

This paper presents a summary of findings and experiences in implementing Roller- Compacted Concrete Pavement (“RCC Pavement”) at industrial distribution facilities. The author’s experiences in RCC Pavement involved defining and taking complete responsibility from concept to completion, including but not limited to, material selection, mixture design, structural design, production, transportation, placement and curing. Using ten-plus years of experience and incorporating pertinent research findings, processes and tests lead to the development of Quality Assurance (“QA”) Processes and Quality Control (“QC”) tests/observations. Continuous improvement has been made on developing a QC program. The author’s experiences involved the use of RCC Pavement as a finished surface and dictated a high performance RCC Pavement (compressive and flexural strength as high as 40 MPa and 5MPa, respectively after only 7 days); therefore, all placement utilized an ABG paver and vibrating screed with dual tamping bars to obtain high density RCC Pavement while minimizing roller displacement and maximizing smoothness and riding characteristics of the final RCC Pavement surface. Size of the projects has limited these experiences to production of RCC Pavement through the use of either a wetbatch concrete plant or a dry-batch concrete plan in conjunction with a horizontal shaft mixer.
The Effect of Faulting on IRI Values for Jointed Concrete Pavements
Authors: Byrum Christopher R. , Perera Rohan W.
Published: January 2025

This paper presents a study on the effects that faulting of joints and cracks in concrete pavements have on International Roughness Index (IRI) values for the pavements. Three methods for comparing faulting to IRI values for roadways are evaluated in this study. The first method is a parametric study on the effect that idealized faulted profiles consisting or rotated line segments having various slab lengths and fault sizes (a saw-tooth pattern) have on IRI values. The second method is a road profile based fault size estimation routine using data from non-contact moving road profilers. Profile based faulting estimates were obtained from over 1000 GPS3 pavement profiles. The third fault measurement method evaluated is the official LTPP field measurement of faulting using the Georgia Faultmeter. This direct measurement method uses the Faultmeter placed over each joint to measure fault sizes. Faulting and IRI can be presented in the same units, m/km (in/mi) for comparison purposes. Based on this study, faulting along the roadway has gain of about 1.75 when converted to IRI. In other words for each 1.58 m/km (100 in/mi) of faulting present, about 2.76 m/km (175 in/mi) of IRI will develop, with gain increasing slightly with increasing fault spacing. The IRI gains measured for real pavement faulting matches the gain values calculated for the ideal saw-tooth patterns. Faulting data can be reliably obtained from relatively inexpensive road profile data that is being obtained for major roadways.
The Second Generation of Minnesota Accelerated Loading Facility - Minne-ALF-2
Authors: Khazanovich Lev , Yut Iliya , Tompkins Derek , Schultz Arturo
Published: January 2025

This paper presents the second generation of Minnesota Accelerated Loading Facility (Minne-ALF-2), a laboratory-based loading pavement test stand that simulates the passage of heavy wheel loads moving over a small full-scale pavement test strip. It is shown that Minne-ALF-2 can provide important information related to long-term performance of dowel joints of concrete pavements, as well as useful information which may lead to a better understanding of the mechanics of joints in concrete pavements. The first results of the ongoing test program are also presented in the paper. This initial study of joint behavior during loading and unloading of a joint with hollow dowels reveals an interesting pattern: deflections in the unloading path are different from the deflections at the loading path. It was also found that the residual differential deflections remain after the first loading and unloading cycle. Available finite element models for rigid pavements do not explain these effects. Hence, advanced models of PCC joints explaining the observed above phenomenon are needed for a better understanding of the joint behavior and joint design optimization.
Tire-Pavement Interaction Noise: Recent Research on Concrete Pavement Surface Type and Texture
Authors: Neithalath Narayanan , Garcia Rolando , Weiss Jason , Olek Jan
Published: January 2025

Several solutions have been proposed for quieter riding surfaces, including porous pavements, tining, and grinding. This paper deals with certain aspects of a recent large-scale research that has been carried out to examine the influence of cement concrete pavement surface type and texture on noise generation. One pavement surface type (Enhanced Porosity Concrete – EPC), and one surface texturing method (transverse tining) is dealt with in detail in this paper. Experimental studies to ascertain the physical (porosity and pore size), mechanical (strength), and acoustical (acoustic absorption using impedance tube) properties of EPC are discussed. It is shown in this paper that, with careful selection of aggregate gradation and cementing materials content, it is possible to generate a system of optimally-sized pores in the material to maximize acoustic absorption. Mathematical modeling of noise to evaluate the influence of transverse tine geometry (depth, width, and shape) on noise reduction characteristics is explained in the second part of this paper. A mathematical model has been used to determine the stress distribution between the concrete pavement and the tire. The stress distribution model is used to describe the stress and ultimately noise generated by various geometries of tining patterns. Experiments on Tire-Pavement test apparatus are also discussed.
Use of Innovative Pre-Cast Concrete Slab Repair Technology in Canada
Authors: Lane Becca , Kazmierowski Tom
Published: January 2025

\In 2004, the Ministry of Transportation Ontario (MTO) carried out a trial project to evaluate construction techniques for pre-cast concrete slab repairs in concrete pavement. The trial was carried out on Highway 427, a heavily trafficked freeway in Toronto, Canada. The trial project required demonstrations of three pre-cast concrete pavement full-depth repair methods: the Fort Miller Super-SlabTM Intermittent Method, the Fort Miller Super-SlabTM Continuous Method, and the Michigan Method. Each method involves designing and fabricating pre-cast concrete slabs to replace deteriorated concrete pavement. The methods differ in how the base is prepared and how the pre-cast slab is installed and dowelled to the existing concrete pavement. Non-destructive testing using a Falling Weight Deflectometer (FWD) was undertaken after construction to assess load transfer efficiency (LTE) and to detect loss of support underneath the pre-cast slab. Details of the methodologies, site conditions, contract specifications, construction and FWD analysis are presented. This is the first construction experience in Canada with innovative pre-cast concrete slab repairs for concrete pavements. MTO will continue to monitor the field performance of these technologies and assess the cost effectiveness of this alternative to full-depth fast-track concrete repairs.
Using Precast Super-Slab® for Rapid Repair of Concrete Pavements
Authors: Smith Peter J. , Barenberg Ernest J.
Published: January 2025

The need for rapidly repairing and replacing concrete pavement has reached near crisis proportions on portions of our most heavily traveled highways. Increasingly heavy traffic flows demand shorter and shorter repair work windows putting more and more pressure on DOT’s to repair such highways invisibly. The practice of using “short term” repairs materials, just because they can be installed rapidly, compounds the problem because repairs made from such materials will themselves need to be repaired in just a few years – in addition to all of the “new” repairs that will need to be made. The use of precast slabs as a material for making rapid repairs has long been entertained because of the durable qualities inherent in concrete slabs manufactured under controlled conditions. The impediment to their use has been the lack of a good way to rapidly and efficiently install them as fully bedded and interlocked precast pavement. This paper will present an overview of the Super- Slab® System that was developed specifically to accomplish that. Specific references will be made to projects that have been successfully completed using the System.
WHY DO OUR CONCRETE PAVEMENTS STILL FAIL?
Authors: Rollings Raymond S.
Published: January 2025

Despite an unprecedented growth in our knowledge and analytical ability, concrete pavements continue to fail more often than we would like. This paper examines a variety of failures encountered by the author in order to try to draw some overall conclusions on why we continue to have such failures. By understanding the types of situations that lead to failure in practice, we may identify how to avoid their reoccurrence in the future.
CONCRETE PAVEMENT – INITIATIVES IN INDIA
Authors: Jain R.K. , Gautam Ashutosh
Published: January 2025

This paper describes the Plain Cement Concrete Pavements being constructed in India in various climatic zones with temperature variations from 4oC to 47oC, annual rainfall from 500 mm to over 2,000 mm, with the relative humidity from 10% to 92%. The pavement construction is being executed with the most modern slip form pavers imported from USA and Germany on high traffic corridors and semi mechanised methods on village access roads. The pavers have built-in automatic dowel bar and tie bar inserters and auto float to iron out the surface irregularities. Pavements in a length of over 2000 km have been completed and opened to traffic. These are now under performance evaluation. A few case studies indicating projects, typical mix designs, problems faced and solutions attempted have been presented.
Decision support model for road pavements based on whole life costing, life cycle assessment and multi-criteria analysis
Authors: Van Leest Adrian J. , Van Hartskamp STeef B. , Meijer Joep P.R.
Published: January 2025

In response to the growing importance of sustainable undertaking, purchasing and building, designers, consultants and pavement managers now tend to make more rational decisions than before when comparing the pros and cons of the construction, maintenance and management of various types of road pavements. Asphalt and concrete pavements offer specific advantages that need to be compared when selecting the most favourable option for long-life pavements. Financial decisions can be based on an analysis of whole life costs, but other important aspects are more difficult to quantify. Factors such as construction risks, the need for maintenance and its impact on accessibility, congestion, road user safety and energy emissions must be qualified and weighted when conducting a comprehensive comparison of pavement performance. A CROW study group has developed a decision support model that can be used to take into account economic, technical, environmental and other factors when selecting a certain type of road pavement. Besides the traditional road pavement materials that can be taken into account, also new materials like light-weight embankment materials, low temperature asphalt, steel fibre reinforced concrete and concrete with recycled aggregates are available in the materials database. The paper describes the methodology used and presents three examples of the model’s application in the Netherlands.
EARLY-AGE SPALLING ON USAF AIRFIELD PAVEMENTS
Authors: Rollings Raymond S. , Poole Toy S. , Rutland Craig , Rollings Marian P.
Published: January 2025

The U.S. Air Force (USAF) has had recurring problem with spalling occurring on new portlandcement concrete airfield pavements at early ages. These appear anywhere from before the pavement is turned over by the contractor to within one year of placement. Past studies of this problem have found early-age spalling is most generally associated with nondurable concrete that results from poor construction practices. The USAF implemented new requirements for mixture proportioning and an education program on the problem that has alleviated the problem to a degree. A recent runway and taxiway construction project is again suffering from early-age spalling, and the investigation to date again indicates nondurable concrete is the culprit.
Experimental Study on Pervious Concrete
Authors: Chen Bing , Liu Juanyu , Li Peng
Published: January 2025

Due to its excellent air and water permeability, pervious concrete has become an environmental friendly material in paving application, providing its benefits in reducing the runoff water, enhancing pavement skid resistance by rapid drainage of water, and reducing pavement noise. However, its high porosity and low strength limit its popularity. Based on the concept of pervious concrete, a mix design approach especially for pervious concrete was proposed and an experimental study was undertaken to produce high performance pervious concrete by using gap-graded coarse aggregates and adjusting cement content. The results indicated that pervious concrete with compressive strength up to 33.5 MPa and permeability coefficient of 6 ml/min can be obtained by using this mix design approach. The results also showed that for pervious concrete made with gap-graded aggregates, the strength increases, and the permeability coefficient decreases with the decrease of the aggregate size. There is an optimum content of cement used to coat the coarse aggregates, enhancing the cement-aggregate interface bonding and overall performance of pervious concrete.
Lessons from Michigan's Oldest Concrete Pavement – Still Serving After 100 Years
Authors: Mailloux Lawrence , Peterson Karl , Van Dam Thomas , Ellis Kyle
Published: January 2025

In 1906, the village of Red Jacket, Michigan (the present day village of Calumet) constructed over 1½ miles of street with a two layer cast in place stamped concrete system known as a granitoid brick block concrete pavement. Today, some of this pavement is still exposed, carrying traffic after 100 years of service. Historical records about the construction and the results of a laboratory analysis of a core specimen from the pavement are presented. The durability of this concrete is remarkable since it was constructed without air entrainment in a severe freeze-thaw climate. The granitoid pavement of Calumet has long outlived the major paving material competitor of its day: creosoted wood block pavement.
Moisture Warping in Jointed Plain Concrete Pavements
Authors: Hansen Will , Wei Ya , Schlangen Erik
Published: January 2025

It is generally believed that slab warping uplift in Jointed Plain Concrete Pavements (JPCP) is caused by drying shrinkage moisture gradients that develop within the top region of a slab cross section. Field experience has shown that excessive moisture warping uplift of joints can develop if a slab on grade is exposed simultaneously to drying at the top and moisture at the bottom surface. The results from this study show that internal self-desiccation causes a uniform reduction in humidity within a cross section for a sealed curing condition. This renders the cross section prone to moisture warping if either the top or bottom surface is exposed to water. Thus, drying at the top and wetting at the bottom create a moisture gradient that causes increased moisture warping uplift. This was verified from beam uplift tests.
Prediction of Spalling and Roughness in the Mechanistic-Empirical Pavement Design Guide
Authors: Hall Kathleen T.
Published: January 2025

This paper documents an assessment of the prediction of joint spalling and International Roughness Index (IRI) for jointed plain concrete pavements (JPCP) in the Mechanistic- Empirical Design Guide (MEPDG) report and software. The role of joint sealant type in the prediction of spalling is examined, as well as the sensitivity of predicted IRI to predicted spalling and other factors. Limitations of the predictive accuracy of the MEDG spalling and IRI models are detailed. Users of the MEPDG and its accompanying software should be aware of the inference space of the data from which these spalling and IRI models were developed, and the practical implications of using the MEPDG models to predict the effect of joint sealant type, joint spalling, climate, and other factors on roughness in jointed plain concrete pavements. The MEPDG software predicts essentially no spalling for joints with preformed sealant, but substantially more spalling – and exactly the same amount of spalling – for unsealed joints, hotpour- sealed joints, and silicone-sealed joints.
Best Practices for Transition Design of Concrete Pavement Intersections and Related Transitions
Authors: Su Jung Youn , Zollinger Dan G. , Tayabji Shiraz D.
Published: January 2025

Pavement transitions are one of the key elements of pavement performance often overlooked in the design process. Improperly designed pavement transition elements lead to poor pavement performance and often creating a need for frequent maintenance and repair. Transition elements are necessary to ensure a smooth transition between two different pavement sections and to minimize future pavement performance issues. This paper addressed the transition of intersections, ramp/gore areas, drainage inlets, and the conversion between a portland cement concrete and asphalt concrete materials. The design standards of most state Department of Transportation (DOT) were reviewed and the best practices identified toward incorporating them into a set of guidelines for design and construction purposes. Moreover, field visits were conducted to survey the conditions of these transition types relative to slab cracking and associated distresses due to inappropriate jointing or other design-related factors. Based on this information, specific design practices are suggested to enhance the design standard for different transition types based on simple and sound concepts substantiated by observed field performance. The guidelines address the design of concrete pavement transition areas including joints and related details.
CONSTRUCTION OF CEMENT CONCRETE PAVEMENT - A CASE STUDY
Authors: Gupta Akhil
Published: January 2025

The paper brings out highlights of execution of Cement Concrete Pavement including Management of Plants & Equipment, Materials, Manpower, Quality Control and overall Logistics. It also attempts to bring out some of critical observations that were made during execution and after opening of pavement to traffic. Some of the causes of failure / defects of Cement Concrete Pavements have also been identified.
Correlation between Properties of Axle Load Distribution and Rigid Pavement Performance Measures
Authors: Haider Syed Waqar , Harichandran Ronald S.
Published: January 2025

The new Mechanistic-Empirical Pavement Design Guide (M-E PDG) utilizes axle load spectra to characterize the unique traffic loadings for a site. These loading characteristics are employed to calculate pavement response and for subsequent damage computations. Generally, these axle load distributions exhibit a bimodal shape and a mixture of two continuous distributions can be used to model them. In this paper, closed-form solutions are developed to estimate the characteristics of a mixture bimodal axle load distribution. The observed axle load spectra from eleven sites in different states were used to relate load distribution characteristics with predicted rigid pavement performance. Cracking performance was related to the 85th percentile load, faulting was found to be strongly related to the overall mean, and roughness (IRI) was strongly associated with the root of the 4th moment of the axle load spectra, respectively. These findings imply that cracking in rigid pavements is mainly caused by the highest 15 percent of loads while faulting is mostly caused by the overall average loads in an axle load distribution. The overall loads, along with higher contributions from the heavier loads, seem to cause higher roughness in rigid pavements. In addition, the relationships developed for different performance measures can directly indicate the relative pavement damage caused by axle distributions.
Experiences with Dowel Bar Retrofit in California
Authors: Kohler Erwin , Harvey John T. , Steven Bruce
Published: January 2025

The technique of Dowel Bar Retrofit (DBR) consists of the installation of dowel bars in concrete pavements originally built without them. This technique is relevant to California because the vast majority of jointed concrete pavements in the state were built without dowel bars, and these pavements are therefore at risk of developing or have already developed step faulting. Many state highway agencies in the United States have tried retrofitting dowel bars into joints and transverse cracks in their concrete pavements, and many have found that DBR extends the life of undowelled pavements by eliminating faulting. Industry records show that more than five million dowel bars have been used in DBR in more than 200 projects in at least 23 states. Information gathered from ten state agencies in the United States revealed positive and negative experiences with DBR. Mixed results have also been experienced in California, however, this paper focuses on the performance from three sites subjected to different climate and traffic loading conditions. These sites have seen excellent performance from the use of different types of dowel bars. The article also briefly mentions other DBR experiences in California.
Influence of Bond Conditions on the Performance of Ultra-Thin Whitetopping (Bonded Concrete Resurfacing)
Authors: Newbolds Scott A. , Olek Jan
Published: January 2025

Ultra-Thin Whitetopping (UTW) is a pavement rehabilitation technique that involves the placement of a thin Portland Cement Concrete (PCC) overlay, 50 mm to 100 mm thick, over a distressed bituminous pavement. Performance of the UTW is dependent on the bond between the two layers. This study evaluated the influence of bond condition on the performance of UTW pavements. Two different test areas were constructed in the INDOT/Purdue University Accelerated Pavement Testing facility. Each test area had different lanes that varied by concrete mix design, bond preparation, and pavement cross-section. These lanes were subjected to approximately 300,000 load applications. The pavements were instrumented and strains were recorded under loading. Evaluations were performed periodically to monitor distress development. With respect to the interfacial bond conditions, the observed amount of distress generally followed the expected trends. Lanes with a lower degree of bonding (partially bonded or unbonded conditions) typically exhibited higher amounts of distress. Conversely, fully bonded lanes typically showed the lowest degree of distress. The interfacial bond conditions did affect the strain distribution and maximum loadinduced strains. The measured strains in the bonded lanes matched the theoretical values well. There was some discrepancy between the measured and theoretical unbonded strain distributions. Further analysis into this discrepancy indicated that even in an unbonded condition there was a moderate level of friction between the UTW and Hot Mix Asphalt (HMA) layers. The interfacial bond conditions did have an influence on the estimated radius of relative stiffness as determined by Falling Weight Deflectometer (FWD). The results indicate that the FWD can be used as a method to determine whether or not the UTW was bonded. However, using the FWD to determine the degree of bonding did not provide very good results. The relative values of the radius of relative stiffness matched the trend exhibited by the bond strengths for cores taken from the same lanes.
New Swedish Design Method for Concrete Pavements
Authors: Silfwerbrand J. , Farhang A. A. , Söderqvist J.
Published: January 2025

A new concrete pavement design method is currently introduced in Sweden. It consists of two parts: (i) computations of subgrade and base distresses and (ii) computations of concrete pavement distresses. To eliminate the difference between concrete and asphalt pavement design, the first part is carried out with equal requirements, in the same manner, and with the very same computer program. The computer run also provides a coefficient of subgrade reaction that is used as input in the second part. For this part, the American FE program ISLAB2000 is used to compute stresses – both traffic and thermal stresses, simultaneously – in various locations of the concrete pavement slab. Contrary to previous Swedish tradition, both bottom-up and top-down cracking are considered in the analysis of the computations. For the pavement designer, the division into two parts will not be visible. She will use the same user-friendly computer program (that previously has only been used for flexible pavement design) for both pavement alternatives. It is the authors’ hope that the selection of pavement solution for a certain case will be dependent solely on technical and economical factors and not on tradition and intensive advertising. The new design method includes a novelty concerning safety philosophy. The safety margin should be obvious and transparent and determined by the client in co-operation with the designer by selecting an appropriate safety class that is dependent on the economical consequences of a pavement failure but independent of material in the wear layer.
Pavement Flexural Fatigue Capacity, and the influence of Mix Charging Sequence
Authors: Moss Justin
Published: January 2025

The durability of concrete pavements is greatly dictated by their capacity to resist fatigue induced by flexural stresses. Known to be a critical factor in fatigue behaviour is the quality (or deterioration under loading) of the bond between the cement paste and aggregate. This paper reports on lab and large-scale trial applications of a range of modified mix charging sequences in terms of their ability to improve the flexural fatigue life of concrete pavements, and also on conventional concrete plastic and hardened properties. Flexural fatigue resistance was assessed using the ASTM C1550 round panel loading test over a range of target failure loads, eg 10² to 106 cycles. Whilst source research was initially focussed on improved distribution of SCMs, this paper demonstrates that similar techniques significantly affect rheology, setting, strength and, in some cases, fatigue capacity and bond quality – all thought to be the result of a modified transition zone (between aggregate and mortar). Importantly, each modified charging sequence was selected or adapted on the basis that such new charging techniques, if shown to be beneficial, could be readily adapted to the common dry batch concrete plants already in use in readymix batching and on-site batching or mixing plants. This study will show that, for a matched mix design, the RILEM method of batching improves the fatigue resistance (and life) of a typical Australian pavement quality concrete by 23% when compared with the conventional batching sequence presently used by premixed and typical on-site concrete batch plants.
Revised Dowel Bar Tolerances for Ontario Concrete Pavements
Authors: Lane Becca , Kazmierowski Tom
Published: January 2025

Effective load transfer is a key design element for jointed plain concrete pavement and has a significant impact on long-term pavement performance. To facilitate load transfer and to allow expansion and contraction of the joints, dowel bars should be placed parallel to the vertical and horizontal planes of the pavement. In the past, it was difficult to verify the alignment of dowel bars within a concrete pavement. Recently, the Ontario Ministry of Transportation was given the opportunity to verify dowel bar alignment with an innovative non-destructive technique known as magnetic imaging tomography (MIT). The MIT scan was found to be a quick and accurate method of measuring dowel bar alignment across a transverse joint, allowing real-time, non-destructive assessment of the dowel bar alignment at joints throughout a concrete paving contract. In Ontario, MIT scan data collection and analysis during concrete paving led to process and equipment improvements. The MIT scan was rapidly adopted both as a quality control tool for the contractor and a quality assurance tool for the ministry. Based on data collected over several paving seasons, changes were made to ministry specifications and dowel bar tolerances. The revised dowel bar tolerances for Ontario pavements are presented in this paper.
Thin whitetopping overlay over a deformed asphalt pavement of a highly trafficked urban intersection
Authors: Gáspár László , Karsai Katalin , Bors Tibor
Published: January 2025

The construction of thin or ultra-thin whitetoppings is considered as an up-to-date rehabilitation technology for flexible pavement structures with repeatedly deformed pavement surface. The experiences on the first use of this technique in Hungary is presented briefly. A highly trafficked urban intersection with traffic signal was the site of the test section. The laboratory investigation of cored samples taken from the deformed pavement structure was followed by cement concrete mix design by KTIinstitute. Four previous trials were carried out in May-July 2007. The experience gained in these trials was utilised in the actual execution of the experimental section in October 2007. The deteriorated asphalt layers were milled in 120 mm depth. A 85 m-long whitetopping in 120 mm thickness was placed using manual paving technique. 1.75x1.75 m slabs were cut in the thin cement concrete layer without joint filler and dowels. The main quality parameters measured of the fresh cement concrete mixture were: slump, air bubble content, density, temperature, optimum time for curing plastic covers, strength. The density, compressive strength, splitting tensile strength, flexural strength, water permeability and surface texture depth were measured on the hardened concrete. After 6 months (severe winter), the section is in excellent condition, no damage can be seen. Several new thin whitetopping sections are planned in Hungary for 2008.
USE OF PROFILE DATA TO DETECT CONCRETE PAVING PROBLEMS
Authors: Kohn Starr D. , Perera Rohan W. , Cable James K. , Karamihas Steven M. , Swanlund Mark
Published: January 2025

The ride quality of a pavement is extremely important to road users. Research has shown that pavements that are built smoother provide a longer service life. Because of these benefits, highway agencies have implemented smoothness specifications to promote construction of pavements that provide road users with the ride quality they expect. A smoothness specification indicates the smoothness level that a contractor must achieve to obtain full payment. In the United States, there is a growing trend of using inertial profilers to collect smoothness data on new portland cement concrete (PCC) pavements and to use the International Roughness Index (IRI) that is computed from the profile data to judge the level of smoothness. Lightweight inertial profilers can collect data on PCC pavement as soon as the PCC has hardened. Repetitive features as well as localized roughness features that are introduced to the pavement profile during paving can be easily detected by analyzing data collected by inertial profilers. This paper illustrates how filtering techniques and power spectral density (PSD) plots can be used to analyze profile data and detect paving problems. The detection of following paving problems from profile data are illustrated in this paper: stringline sag, roughness caused by dowel effects, mechanical oscillating floats, and headers.
Pembelajaran Berbasis Science Technology Engineering and Mathematics Meningkatkan Kemampuan Siswa Dalam Pemecahan Masalah Matematis
Authors: Medi Dwi Utari  , Imam Kusmaryono  , Mochamad Abdul Basir
Published: January 2025

Salah satu tujuan pembelajaran matematika adalah membekali siswa agar dapat memecahkan masalah. Namun, hasil observasi menunjukkan kemampuan pemecahan masalah matematis siswa masih belum maksimal atau tergolong rendah. Tujuan penelitian ini untuk menganalisis pembelajaran berbasis STEM dalam meningkatkan kemampuan pemecahan masalah matematis siswa kelas VIII pada materi statistika. Metode penelitian yang digunakan adalah deskriptif dengan pendekatan kualitatif. Adapun subjek penelitian adalah siswa kelas VIII F MTs Negeri 2 Kota Semarang yang berjumlah 34 siswa. Instrumen penelitian yang digunakan yaitu lembar observasi, lembar kerja siswa terdiri tiga buah dan pedoman wawancara. Hasil penelitian menunjukkan bahwa pembelajaran berbasis STEM pada materi statistika dilaksanakan melalui tahap ask, imagine, plan, create, dan improve dengan mengintegrasikan setiap aspek science, technology, engineering dan mathematics ke dalam proses pembelajaran. Siswa disajikan permasalahan dalam kehidupan sehari-hari atau dunia nyata yang relevan kemudian melalui tahap asksiswa mengidentifikasi masalah. Tahap imagine siswa memikirkan solusi yang terbaik untuk menyelesaikan masalah berdasarkan konsep dan pada tahap plan siswa membuat rancangan penyelesaian agar solusi yang dipilih dapat digunakan. Pada tahap create siswa melaksanakan penyelesaian masalah berdasarkan rancangan yang dibuat dan di tahap akhir yaitu improve siswa membuat kesimpulan atas hasil yang diperoleh. Kemampuan pemecahan masalah matematis siswa meningkat di setiap pertemuan, dan kemampuan pemecahan masalah siswa sebesar 80,87% yang dikategorikan Baik.
Proses Pembelajaran Berdiferensiasi terhadap Peningkatan Kemampuan Berpikir Kritis Pada Materi Operasi Hitung Aljabar
Authors: Hidayah Nur , Kusmaryono Imam , Abdul Basir Mochamad
Published: January 2025

Pembelajaran berdiferensiasi digunakan untuk memenuhi kebutuhan siswa dalam memahami materi pembelajaran sehingga kemampuan berpikir kritis siswa dapat meningkat. Penelitian ini bertujuan untuk menganalisis proses pembelajaran berdiferensiasi terhadap peningkatan kemampuan berpikir kritis pada materi operasi hitung aljabar. Metode yang digunakan yaitu metode kualitatif dengan jenis studi kasus. Penelitian ini dilaksanakan di SMP Islam Sultan Agung Semarang dengan subjek penelitian adalah guru matematika dan 30 siswa kelas VII A5. Teknik pengumpulan data dilaksanakan dengan observasi, wawancara, tes, dan studi dokumen. Hasil penelitian ini yaitu langkah pembelajaran dengan identifikasi keragaman, membagi kelompok siswa, memberikan diferensiasi konten, memberikan diferensiasi proses, dan memberikan diferensiasi produk. Lembar kerja yang diberikan memuat langkah FRISCO. Focus difasilitasi dengan bentuk soal PGK berupa langkah-langkah, uraian, dan soal cerita. Reason difasilitasi guru memberikan pendekatan agar siswa dapat mengkonstruksi konsep dengan tahapan-tahapan yang telah diberikan guru. Inference difasilitasi guru membantu siswa membuat kesimpulan yang tepat. Situation difasilitasi guru memberikan arahan agar semua diisi dan dicek pengerjaan siswa secara berkala. Clarity difasilitasi guru memberikan tugas yang dikaitkan dengan kehidupan sehari-hari. Overview difasilitasi guru memberikan stimulus, waktu pengerjaan, dan arahan untuk mengecek ulang jawaban sebelum dikumpulkan. Peningkatan kemampuan berpikir kritis terbukti dari nilai lembar kerja pertemuan pertama, kedua, ketiga, dan tes kemampuan berpikir kritis. Inteval nilai 81-100 dengan kategori sangat tinggi meningkat 100%. Indikator kemampuan berpikir kritis juga dipenuhi rata-rata 90% siswa.
Kata Kunci: Kemampuan Berpikir Kritis, Pembelajaran Berdiferensiasi
Expanding quantitative energy transition modelling research processes within LMICs to integrate qualitative considerations and methodologies.
Authors: Fields Neve , Martindale Leigh , Bergman Marissa , Howells Mark , Brown Ed
Published: January 2025

Access to clean energy is crucial for reducing greenhouse gas emission, improving livelihoods and enabling critical development efforts in sectors such as education, health, and the economy which often disproportionately impact vulnerable and marginalised groups. Energy transition research has emerged within energy planning in low- and middle-income countries (LMICs) to address the need to transition to clean, renewable, and efficient energy alongside meeting the increasing economic, social, behavioural, and technological needs of a developing society. Quantitative energy transition modelling is a widely employed methodology for analysing energy systems and providing insights into possible future development pathways. Yet such methods are often critiqued for their reductionary nature, and failure to capture the wider contextual real-world complexities in which energy decisions are made. Integrating qualitative methodologies and considerations into energy modelling processes offers an opportunity to strengthen techno-economic based research, more successfully capturing the parameters and boundaries in which energy planning processes sit. This research will attempt to conceptualise the integration of qualitative methodologies into quantitative modelling research for LMICs. This research recommends that qualitative considerations, such as social dynamics, human behaviour and institutional factors alongside a particular focus on gender and social inclusion (GESI), resilience and climate adaptation awareness, be examined and integrated at all stages of the modelling research process, conceptualised into four phases: (1) ‘Pre-Modelling’, (2) ‘Storytelling and Narratives’, (3) ‘The Model’, and (4) ‘Beyond the Model’.
Endocervical adenocarcinoma secondary to HPV in a young woman
Authors: Lopes Bruna Mariah Martins Batista , Riva Ana Carolina Fernandes Dala , Silva Luísa de Oliveira e , Machado Gabriel Canhete , Carvalho Glaucia Alves de , Scherer Aline , Lagemann Bruna , Mettifogo Isadora Bolfarini Guiotti , Medina Gabriela Paladini Cardoso
Published: January 2025

Considering the relationship between persistent HPV infections and the development of endocervical adenocarcinomas in young women, this study aims to report a rare case of invasive endocervical adenocarcinoma in a 28-year-old patient. To this end, clinical follow-up was carried out for the patient, who had risk factors such as smoking, early sexual debut, and lack of HPV vaccination. The diagnosis was made through biopsy and conization, followed by laparoscopic hysterectomy. It is observed that even in young women, persistent high-risk HPV infections can lead to the development of neoplasms, highlighting the importance of vaccination and early screening. It is concluded that individualized management and early diagnosis are essential for successful treatment in rare cases like this.
Bell’s Palsy in a pregnant woman: case report associated with Ramsay Hunt Syndrome
Authors: Machado Gabriel Canhete , Lagemann Bruna , Mettifogo Isadora Bolfarini Guiotti , Medina Gabriela Paladini Cardoso , Scherer Aline , Lopes Bruna Mariah Martins Batista , Silva Luísa de Oliveira e , Riva Ana Carolina Fernandes Dala , Carvalho Glaucia Alves de
Published: January 2025

Considering that Bell's palsy in pregnant women can present with increased severity and incomplete recovery rates, this work aims to discuss the complexity of managing this condition during pregnancy, especially when associated with Ramsay Hunt syndrome. To this end, we analyze a clinical case of a 30-year-old Brazilian woman, 33 weeks pregnant, who developed unilateral facial paralysis and complications such as cholestasis and chorangioma, leading to an emergency cesarean section. It is observed that, despite treatment with acyclovir and prednisone, the patient experienced persistent symptoms, including facial weakness and hearing loss. These results emphasize the need for a multidisciplinary approach in managing Bell's palsy in pregnant women, highlighting the importance of integrated care for maternal and fetal health. It is concluded that effective treatment requires careful consideration of the risks and benefits of medications, as well as ongoing follow-up to optimize outcomes and the patient's recovery (Guimarães, 2005).
MathFact: herramienta innovadora y significativa en la enseñanza-aprendizaje de la factorización de polinomios algebraicos
Authors: Sepúlveda Aura Elisa Quesada , Losada Walter Murcia
Published: January 2025

Este proyecto de investigación se centró en la incorporación de las Tecnologías de la Información y la Comunicación (TIC) en el proceso de enseñanza-aprendizaje, mediante la implementación de la aplicación MathFact. Esta herramienta lúdica se utilizó para desarrollar estrategias que mejoraran el rendimiento académico de los estudiantes de grado 8° en el tema de factorización de polinomios algebraicos, permitiendo un aprendizaje innovador y significativo.
Las matemáticas, frecuentemente consideradas una de las materias más desafiantes, no son la excepción en la Institución Educativa Villa de los Andes, como lo evidencian los resultados en diversas evaluaciones. Ante esta situación, se identificó la necesidad de optimizar el aprendizaje, especialmente en la factorización de polinomios algebraicos. MathFact permitió a los estudiantes transformar el lenguaje algebraico en geométrico, relacionando la factorización con el área de un rectángulo. Al identificar la base y la altura del rectángulo, los estudiantes hallaron tanto el área como la solución para factorizar el polinomio.
El estudio adoptó un enfoque mixto, combinando datos cuantitativos (evaluaciones diagnóstica y final) y cualitativos (encuestas de percepción). La metodología fue cuasiexperimental, con dos grupos: experimental y control. Los resultados mostraron que el grupo experimental, al interactuar con la estrategia tecnológica, mejoró su percepción de las matemáticas, mostrando mayor comprensión y participación. En cambio, el grupo control presentó dificultades al no utilizar la herramienta.
Frontiers in Latin America: A Political Ontology
Authors: Serje Margarita
Published: January 2025

This paper is concerned with frontiers as spaces of disputed, ceded, suspended, or imposed forms of rule, that challenge the integrity of bounded territorial polities and their jigsaw puzzle-limits. In recent decades, frontiers have received increased attention, perhaps due to the growing importance “marginal” and “ungoverned spaces” have acquired within the global economy. In spite of their enormous diversity of climates, landscapes and societies, frontiers in Latin America have historically been described and intervened in surprisingly similar ways. The ‘idea’ of the frontier is here so intertwined with the reality of these places, that they have become indistinguishable. This article explores the production of frontiers, more than as a type of space, as an object of common sense and intervention. From an ontological point of view, its aim is to problematize the way frontiers are produced and enacted as an object, constituted and enacted in practice, by dissecting its constitutive practices: what is categorized as a frontier, how is it categorized; and its constitutive relations: the conditions and possibilities created by the frontier that empower certain groups and create new systems of access and control of land and resources.