Speed Studies

There are two different approaches to represent speed Studies. 1) Spot Speed 2) Average speed. 2) Average speed- There are two types of average speed.a) Time mean speed b) Space mean speed Spot Speed It is the instantaneous speed of a vehicle. It can be measured using an Endoscope, Loop deflector, and Pressure contact tubes.Spot…

DESIGN OF RIGID PAVEMENT

Rigidity is due to high modulus of elasticity of concrete. Cement concrete pavement is rested on soil foundation which can be treated as a spring offers the modulus of subgrade reaction. Modulus of subgrade reaction (by Westergaard) K=p/Δ in kg/cm3 The radius of relative stiffness- Relative stiffness of slab with respect to subgrade is represented…

Methods Of Pavement Design

a) Empirical methods – Methods are based on physical properties and strength parameters of soil subgrade. Ex is bG.I/CBR/Stabilometer/Mc-Leod Methodsb) Semi-Empirical – Methods are based on stress-strain function. Ex Triaxial Methodc) Theoretical Method- Based on mathematical computation. Ex Burmister Method which is based on Elastic theory G.I. Method Computation is explained in Highway material To…

EQUIVALENT SINGLE WHEEL LOAD (ESWL) is considered for the Fixed traffic approach (Airport Pavement design- where a number of repetitions not considered) as one single load movement is sufficient to cause damage to pavements. ESWL is the single wheel load that produces the same value of maximum stresses at the depth Z as the dual…

PAVEMENT

A highway PAVEMENT DESIGN may be a structure consisting of superimposed layers of processed materials higher than the natural soil sub-grade, whose primary perform is to distribute the applied vehicle masses to the sub-grade. The pavement structure ought to be able to give a surface of acceptable riding quality, adequate skid resistance, favorable light-weight reflective…

Properties Of Bitumen as a Highway Material

Following are the materials to deal with in highway materials. Soil Characteristics, Stone Characteristics, Bituminous Characteristics. BITUMINOUS CHARACTERISTICS Bitumen is used in road construction because of its varied properties and benefits it’s over alternative pavement construction materials. Bitumen gains sure distinctive properties that are integral in it throughout its manufacture. The hydrocarbon as a staple in…

Properties Of Stone as a Highway Material

Following are the materials to deal with in highway materials. Soil Characteristics, Stone Characteristics, Bituminous Characteristics.Desirable Properties Of Stone as a Highway Material a) Strength- They should be strong enough to withstand stresses due to traffic wheel loadb) Hardness- They should be hard enough to resist wear and tear due to abrasive action. The mutual…

Properties Of Soil as a Highway Material

Properties Of Soil as a Highway Material- Following are the materials to deal with in highway materials Soil Characteristics Stone Characteristics Bituminous Characteristics SOIL CHARACTERISTIC Soil is considered as one of the principal highways materials, compacted soil, and stabilized soil are often used in subgrade or base course of highway pavement Desirable Properties:- a) Stability…

ENGINEERING SURVEYS FOR HIGHWAY LOCATION

Before highway alignment is finalized in Highway project, the engineering surveys are to be carried out. The stages of engineering are: (a) Map study :- Topographic maps are available from the survey of India with 15 to 30 meter contour intervals. Valley, ponds or lakes etc. can be avoided and approximate position of bridges etc.…

HIGHWAY DEVELOPMENT AND PLANNING

(a) Roman Roads →312 BC constructed 580km (length)Features(1) They were straight regardless of gradients(2) Total thickness was (.75 to 1.2) meter(3) The wearing course consisted of dressed large stone blocks set in lime mortar. (b) Tresaguet construction (France -1764AD)(1)Thickness -30cm(2)Consideration was given to subgrade moisture and drainage of surface water(3) The top-wearing surface was made…