Difference between flexible and rigid pavements civil snapshot. Flexible pavements on the other hand, rigid pavements are associated with rigidity or flexural strength or slab action so the load is distributed over a wide area of subgrade soil. Following are the different components of road structure. For simplicity and not going much deeper in the differentiation the following points can be listed as difference between them. The designing of pavement is one of the challenging tasks in transportation engineering. Engineers must always determine the requirements of the. Flexible pavements carries such name, because the entire pavement has the elastic deflection under load. Width of the carriage way depends on the number of the lanes in the road.
Apr 02, 2020 flexible and rigid pavement are the two basic styles of road surfaces. Pdf guidelines on composite pavement design and evaluation. The rigid pavements are made with portland cement concreteeither plain, reinforced or prestressed concrete the plain cement concrete slabs are expected to take. Difference between flexible and rigid pavements civil. The pavements transition between flexible and rigid between mm 196 and mm 197, in both directions. In rigid pavements, the stresses are not transferred from grain to grain to the lower layers as in the ease of flexible pavement layers. Critical condition of stress in the rigid pavement is the maximum flexural stress occurring in the slab due to wheel load and the temperature changes. The sections between mm 189 to mm 196 are flexible pavements in both directions and the sections between mm 197 and mm 204 are rigid pavements in both directions.
The concrete slab itself supplies a major portion of a rigid. Very often in civil engineering, during the design of pavements aimed for traffic flow of heavy vehicles, the question of choosing between two types of pavements flexible and rigid pavement comes to the fore. A total of 90 flexible pavements and 63 rigid pavements are designed and their costs computed. The pavement design is also one major factor, with flexible pavements reliant on subgrade strength and rigid pavement dependent on the flexural strength of concrete. It is generally central portion of the total land width and the bituminous concrete is placed or paved as to provide good service for the users. Flexible pavement has very low modulus of elasticity less strength. The above same scenario is also applicable while we construct rigid pavements. On the other hand, rigid pavements consist of portland cement based. Load transfer is from grain to grain to the lower layers. The main differences between the flexible pavement and rigid pavement.
The pavement surface should be durable and it can withstand the load acting from the wheel tyres. Rigid pavement is laid in slabs with steel reinforcement. In the design of flexible pavements, traffic load is expressed in terms of million equivalent single axle load esals. Comparision between rigid and flexible pavement 7537 words. Report on engineering comparison between flexible and rigid pavement submitted by. Flexible and rigid pavement are designed for similar soil and traffic conditions using appropriately related, different methods and their costs are compared. Difference between flexible and rigid pavement properties.
Functional and structural flexible pavement overlay o esign. Are those pavements which reflect the deformation of subgrade and the subsequent layers to the surface. Jointed plain concrete pavement is the most common type of rigid pavement. Ald makes it possible to design the two types of pavements. Flexible and rigid pavement are the two basic styles of road surfaces. What is the difference between rigid pavement and flexible. The essential difference between the two types of pavements, flexible and rigid, is the manner in which they distribute the load over the subgrade. Flexible pavements are those which are surfaced with bituminous or asphalt materials. Flexible pavement rigid pavement the earthen, gravel, water bound mac. The pavement structure consists of the bitumen bound materials, hence they are more elastic than rigid and more deformable. Sep 16, 2018 difference between rigid pavement and flexible pavement 1.
The demand for better roads and services required researchers. Flexible pavement load transfer is from grain to grain to the lower layers the design greatly depends upon the subgrade strength irc 372012 code is used for designing flexible paveme. Rigid pavement, because of concretes rigidity and stiffness, tends to distribute the load over a relatively wide area of subgrade. Types of pavement flexible and rigid pavement there are two types of pavements based on design considerations i. The unified facilities criteria ufc system is prescribed by milstd 3007 and provides planning, design, construction, sustainment, restoration, and modernization criteria, and applies. Irc 372012 code is used for designing flexible pavement the stability of flexible pavement depends upon aggregate interlock, particle friction and cohesion. Oct 04, 2017 flexible and rigid difference with complete details leacture. Rigid pavement and flexible pavement are the two types of road pavement design methods.
Joints in rigid pavement transportation engineering july 12, 2019 august 21. It is not intended as definitive treatise, and it does not encompass the design of rigid pavements. Section 4 flexible pavement construction standard specification for urban infrastructure works 41 edition 1, revision 02 oct 2010 contents revision register 42 4 flexible pavement construction 43 4. Cement concrete roads are known as rigid pavement inflexible pavement the top surface takes the shape of the subsurface soil e. Advantage and disadvantage of flexible and rigid pavement. The design greatly depends upon the subgrade strength.
Before we differentiate between flexible pavements and rigid pavements, it is better to first know about them. Westergaard is considered the pioneer in providing the. Difference between flexible pavements and rigid pavements. Jpcp does not use any reinforcing steel but uses dowel bars and tie bars.
Types of pavement pdf free download engineering society. This has led for a need of rapid construction of roads and transportation infrastructure. In highway engineering, what is the difference between a. The difference between a structure that is rigid and one that is flexible is that the rigid structure will not bend or flex when force is applied. Jan 10, 2018 learn the basic differences between flexible and rigid pavements. Types of pavements flexible pavements and rigid pavements. The earthen, gravel, water bound macadam and bituminous roads are known as flexible pavement. Made of cement concrete either plain, reinforced or prestressed concrete. The difference between these two styles mostly comes down to deformation. Impact of design features on pavement response and. The rigid pavements posses noteworthy flexural strength or flexural rigidity. Learn the basic differences between flexible and rigid pavements.
Flexible pavements use bitumen as binder while rigid use concrete. The main point of difference in the structural behavior of rigid pavement compared to the flexible pavement is the critical condition of stress from the rigid pavement ist that the maximum flexural stress was occurring from the slab because of wheel load and the temperature changes whereas from the flexible pavement its the distribution. Flexible pavement differ from rigid pavement in terms of load distribution. Its flexible since the total pavement structure bends or deflects due to the traffic loads. Plate bearing tests for design of flexible and rigid pavements e. Difference between rigid pavement and flexible pavement 1. Difference between flexible pavement and rigid pavement duration. Structural capacity of flexible pavement depends on the characteristics of every single layer. The costs include the construction cost and a fixed maintenance cost. Functional and structural flexible pavement overlay o. Flexible pavement is almost always asphalt while rigid pavement is concrete. The rigid pavements are made of cement concrete either plan, reinforced or prestressed concrete. Joints in rigid pavement transportation engineering.
Comparative studies of flexible and rigid pavement design methods. What is the difference between flexible and rigid pavements. Engineers are cautioned that much of pavement design is governed by codes, specifications and practices of public agencies. Updated on feb 2017 carriageway a carriage way is defined as the width or portion of road which is used by the vehicular traffic for their movement. The report supplements previous papers on pavement design, particularly the study reported in 1952. The concrete pavements are now a days becoming more popular in india because of steep rise in the cost of bituminous pavement. Flexible pavement allows for significant deformation under heavy loads. Difference between flexible and rigid pavement engineering. In analyzing the research data collected, a deficiency in the 1986. Today the majority of us state agencies build jointed plain pavements. Psi difference between the initial design serviceability index. The last century has seen an intensive process of urbanization in rural as well as metro cities. Pdf a comparative study on rigid and flexible pavement. Ufc 325001 pavement design for roads and parking areas.
Key words flexible pavement, rigid pavement, lifecycle cost. While, the structural capacity of rigid pavements is. Rigid pavements are those which contain great amount of flexural strength or flexural rigidity. The critical line of equal costs on the plane of cbr versus msa is also. The rigid characteristic of the pavement are associated. Design flexible and rigid pavements 9design principlespavement components and their roledesign practice for flexible and rigid pavements, ircmethods only.
In this case, the load carrying capacity is mainly due to the rigidity ad high modulus of elasticity of the slab slab action. Modulus of elasticity of rigid pavement is very high, because of high strength concrete and more load bearing capacity of the pavement itself. The research findings provided guidance to identify appropriate features and rehabilitation alternatives for different pavement types and recommendations for improving data collection activities. Besides, rigid pavements in spite of their high initial cost, are proven to be more economic than flexible type pavements when due considerations are made to life cycle cost and all types of.
Mathematical expressions are developed to relate the cost of pavements with soil cbr and traffic in msa. The essential difference between flexible and rigid pavement are as follows. Plate bearing tests for design of flexible and rigid pavements. The main difference between the flexible and rigid pavements is based on the manner in which the loads are distributed to the subgrade. Director, csircentral road research institute, delhi two types of pavements are laid in india rigid pavement and flexible pavement. The rigid characteristic of the pavement are associated with rigidity or flexural strength or slab action so the load is distributed over a wide area of sub grade soil. They are usually laid in slabs with steel reinforcement, with design based on providing a structural cement concrete slab of sufficient strength to resist the loads from traffic. This paper compares for india the properties and costs of a cement concrete rigid pavement with those of a flexible pavement, composed of granular material, waterbound macadam, and a bituminous course. The pressures arent transferred from grain with the lower layers, as in the ease of flexible pavement layers. Comparison between flexible pavement and rigid pavement in. In simple terms, a flexible pavement can be defined as a pavement layer comprising of a mixture of aggregates and bitumen, heated and mixed properly and then laid and compacted on a bed of granular layer. Jpcp controls cracks by dividing the pavement up into individual slabs separated by contraction joints.
Difference between flexible and rigid pavements is based on the manner in which the loads are distributed to the subgrade. Oct 02, 2017 the essential difference between flexible and rigid pavement are as follows. What is the difference between flexible and rigid pavement. Width of the carriage way depends on the number of the lanes in the road which again depends on the. Functional and structural flexible pavement overlay o esign for indiana to overcome a deficiency in the 1986 aashto guide jay k. Difference between flexible and rigid pavements 0 2 minutes read a pavement or road is a structure consisting of superimposed layers of processed materials above the natural soil subgrade, whose primary function is to distribute the applied vehicle loads to the subgrade. Following are the difference between flexible pavements and rigid pavements such as. Rigid pavements as the name shows are like rigid slabs placed on earth which takes load by itself though its strength and rigidity.
Comparative studies of flexible and rigid pavement design. Director, csircentral road research institute, delhi two types of pavements are laid in indiarigid pavement and flexible pavement. This is an introduction to flexible pavement design for engineers. While, in case of rigid pavements most of the load carries by slab itself and slight load goes to the underlying strata.
Surface course or wearing course all these components belong to a typical flexible pavement, whereas rigid pavement usually consists of subgrade, subbase and a concrete slab. Yoder research engineer joint highway research project purdue university synopsis this paper presents the results of a study of pavement design based on the plate bearing list. There are two types of pavements based on design considerations i. Comparision between rigid and flexible pavement 7537. Rigid pavement fig no2 rigid pavements are those that possess noteworthy flexural strength or flexural rigidity. This video shows the main differences between the flexible pavement and rigid pavement. In flexible pavements load distribution is primarily based on layered system. Types of pavements flexible pavement rigid pavement. Apr 27, 2015 updated on feb 2017 carriageway a carriage way is defined as the width or portion of road which is used by the vehicular traffic for their movement. Difference between flexible and rigid pavements is based on the manner in which the. In flexible pavements, underlying layers play very important role. Difference between flexible pavement and rigid pavement. There are two two types of pavements used in transportation projects, but which type of pavement should engineer choose while designing the project so it depends on various factors, like the durability of project, the cost of project and much more.
Longterm pavement performance program specific pavement study sps5 and sps6 experiments provided information to obtain a better understanding of the effects of design and construction features on pavement response and performance of rehabilitated flexible and rigid pavements. You created this pdf from an application that is not licensed to print to. Generally this type of pavement requires some sort of maintenance or restoration every 10 to 15 years. Dec, 2016 critical condition of stress in the rigid pavement is the maximum flexural stress occurring in the slab due to wheel load and the temperature changes. The analyses results obtained in this study helped determine the causes of distress and helped formulate. Difference between flexible and rigid pavements is based on the. Rigid pavement is designed and analyzed by using the elastic theory.
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