The Question of Shear in the Design of Pavement Structures

Author(s):  
A. Bensalem ◽  
A. Brown
Keyword(s):  
2018 ◽  
pp. 128-145
Author(s):  
Volodynyr Mozghovyi ◽  
◽  
Viktor Gaidaichuk ◽  
Yurii Zaiets ◽  
Liudmyla Shevchuk ◽  
...  

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 74
Author(s):  
Hatem Alhazmi ◽  
Syyed Adnan Raheel Shah ◽  
Muhammad Aamir Basheer

Rigid pavement structures are one of the costly components of the infrastructure development process. It consumes a huge quantity of ingredients necessary for concrete development. Hence, a newly introduced concept of circular economy in combination with waste management was introduced to solve this problem. In this study, three waste products (rice husk ash (RHA), wood sawdust (WSD), and processes waste tea (PWT)) was utilized to develop the concrete for rigid pavement structures by replacing the sand, i.e., a filler material at different percentages. During the testing procedure of compressive (CS), tensile (TS), and flexural strength (FS) properties, RHA and WSD at 5% replacement were found to be a good replacement of sand to develop required concrete. This study will help in the production of eco-friendly rigid pavement structures and a pathway of life cycle assessment in the future.


Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 563
Author(s):  
Łukasz Skotnicki ◽  
Jarosław Kuźniewski ◽  
Antoni Szydło

The reduction in natural resources and aspects of environmental protection necessitate alternative uses of waste materials in the area of construction. Recycling is also observed in road construction where mineral–cement emulsion (MCE) mixtures are applied. The MCE mix is a conglomerate that can be used to make the base layer in road pavement structures. MCE mixes contain reclaimed asphalt from old, degraded road surfaces, aggregate improving the gradation, asphalt emulsion, and cement as a binder. The use of these ingredients, especially cement, can cause shrinkage and cracks in road layers. The article presents selected issues related to the problem of cracking in MCE mixtures. The authors of the study focused on reducing the cracking phenomenon in MCE mixes by using an innovative cement binder with recycled materials. The innovative cement binder based on dusty by-products from cement plants also contributes to the optimization of the recycling process in road surfaces. The research was carried out in the field of stiffness, fatigue life, crack resistance, and shrinkage analysis of mineral–cement emulsion mixes. It was found that it was possible to reduce the stiffness and the cracking in MCE mixes. The use of innovative binders will positively affect the durability of road pavements.


Aviation ◽  
2014 ◽  
Vol 18 (2) ◽  
pp. 72-79
Author(s):  
Ervina Ahyudanari ◽  
Nasir Shafiq ◽  
Ibrahim Kamaruddin

Preserving airport pavement means guarantying the safety operation of aircraft movements. There are four aspects that cause progressive pavement deterioration, i.e. the construction design and process, selected material, and maintenance management. One of the traffic aspects, jet engine exhaust, has not been discovered yet. The load pattern of the jet exhaust follows the schedule of aircraft traffic. The assumption held in this research is that the thermal load during aircraft movement may generate a high temperature, which is induced into pavement layers. The objective of this research is to determine the temperature gradient in the pavement, caused by the jet exhaust. This paper discusses the process of determining the temperature gradient in four stages, i.e. by carrying out the gap analysis, evaluation of pavement structures, determination of the load path and the magnitude, and defining the temperature gradient. The temperature gradient in the pavement layer is determined through the development of a model of cyclic loading. The thermal cyclic load follows the aircraft schedule pattern. The pavement temperature receives the thermal cyclic load of the sinusoid of solar radiation. The results indicate that the temperature of the pavement is increased and pavement temperature rises by 35 °C. However, after 60 seconds the remaining temperature of the pavement layer decreases to the initial temperature, which is caused by solar radiation.


2003 ◽  
Vol 1855 (1) ◽  
pp. 176-182 ◽  
Author(s):  
Weng On Tam ◽  
Harold Von Quintus

Traffic data are a key element for the design and analysis of pavement structures. Automatic vehicle-classification and weigh-in-motion (WIM) data are collected by most state highway agencies for various purposes that include pavement design. Equivalent single-axle loads have had widespread use for pavement design. However, procedures being developed under NCHRP require the use of axle-load spectra. The Long-Term Pavement Performance database contains a wealth of traffic data and was selected to develop traffic defaults in support of NCHRP 1-37A as well as other mechanistic-empirical design procedures. Automated vehicle-classification data were used to develop defaults that account for the distribution of truck volumes by class. Analyses also were conducted to determine direction and lane-distribution factors. WIM data were used to develop defaults to account for the axle-weight distributions and number of axles per vehicle for each truck type. The results of these analyses led to the establishment of traffic defaults for use in mechanistic-empirical design procedures.


Author(s):  
Randy B. Machemehl ◽  
Feng Wang ◽  
Jorge A. Prozzi

Truck tire inflation pressure plays an important role in the tire–pavement interaction process. As a conventional approximation method in many pavement studies, tire–pavement contact stress is frequently assumed to be uniformly distributed over a circular contact area and to be simply equal to the tire pressure. However, recent studies have demonstrated that the tire–pavement contact stress is far from uniformly distributed. Measured tire–pavement contact stress data were input into an elastic multilayer pavement analysis program to compute pavement immediate responses. Two asphalt concrete pavement structures, a thick pavement and a thin pavement, were investigated. Major pavement responses at locations in the pavement structures were computed with the measured tire–pavement contact stress data and were compared with the conventional method. The computation results showed that the conventional method tends to underestimate pavement responses at low tire pressures and to overestimate pavement responses at high tire pressures. A two-way analysis of variance model was used to compare the pavement responses to identify the effects of truck tire pressure on immediate pavement responses. Statistical analysis found that tire pressure was significantly related to tensile strains at the bottom of the asphalt concrete layer and stresses near the pavement surface for both the thick and thin pavement structures. However, tire pressure effects on vertical strain at the top of the subgrade were minor, especially in the thick pavement.


2017 ◽  
Vol 37 (1) ◽  
pp. 43 ◽  
Author(s):  
Vanessa Senior Arrieta ◽  
Jorge Eliecer Córdoba Maquilon

Porous asphalt mixes (PAM), form a special road surface for asphalt pavement structures, have a special particle size distribution that lets infiltrate to the runoff storm water through of it because of its voids content about 20 %. Many researchers conducted studies and have concluded that the use of modified asphalts is completely necessary to design PAM. Organic and chemical additives and special procedures as foamed asphalt have enhanced the performance of PAM, during their service life. This paper is focused on the mechanical characterization of PAM and how the asphalt modified with fatty acid amides, influenced on their behavior and performance. Based on an experimental methodology with laboratory tests aimed at establishing a comparison between porous asphalt mixes, using for its design and production a penetration 60-70 pure asphalt and another one asphalt modified with fatty acid amides.


2012 ◽  
Vol 594-597 ◽  
pp. 1445-1448
Author(s):  
Tao Cheng ◽  
Ke Qin Yan

Mechanics properties of lime- fly ash stabilized soil are investigated. First, the chemical composition of fly ash are analyzed by spectral analysis test. Compaction experiments of all mix proportion projects are carried out in different water conditions to obtain the optimum water contents. Then the optimum mix proportion is obtained by the unconfined compressive strength and the compression rebound modulus test. Finally, the pavement structures design for a highway of lime- fly ash stabilized soil road sub-base is done. By the comparison, a conclusion can be drawn that lime-fly ash stabilized soil is suitable for flexible pavement or semi-rigid pavement because of its good strength and rigidity which can effectively reduce thickness of the lower pavement and basic deflection.


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