Showing posts from May, 2014

Failures in Rigid Pavements

With the reference of the book titled as 'Highway Engineering,'  by S.K.Khanna and C.E.G.Justo, I created this post, which covers the failures in rigid pavements. If you have the book, please consult the book, because that would be a better option. Failures in cement concrete pavements are recognized mainly by the formation of the structural cracking.
Failures occur due to two factors: (a) Deficiency of the pavement materials. (b) Structural in-adequacy of the pavement system.
Deficiency of the Pavement Materials:Soft aggregatesPoor workmanship in joint constructionPoor joint filler or sealer materialPoor surface finishImproper and insufficient curing.Here are the various defects that creep in due to the causes above:
Dis-integration of the cement concreteFormation of crackingSpalling of joints.Poor riding surfaceSlippery surfaceFormation of shrinkage cracksIngress of surface water and further progressive failures.Structural in-adequacy of Pavement System:Inadequate sub-grade su…

Traffic Capacity Studies (Highway Engineering)

Hi there,
How you doing?
As we know, traffic volume is the numbers of vehicles that pass a point on a highway on a particular lane on particular direction in unit time, generally in per unit hour, there is a term which represents the capacity of a road to accommodate the traffic volume.
Traffic capacity is expressed as the maximum number of vehicle in a lane or a road that can pass a given point in unit time, usually an hour, i.e., vehicles per hour per lane or roadway.

Traffic capacity and traffic volume has same units, difference between the two is that traffic volume represents the actual rate of flow of the traffic and responds to the variation in the traffic demand, while capacity indicates a capability or maximum rate of flow with a certain level of service characteristics that can be carried by the road.

Traffic capacity of a roadway depends upon a number of prevailing roadway and traffic conditions.

Basic capacity is the maximum number of vehicles(PCU) that can pass a given poin…

Failures of Flexible Pavements

Hi there,

Failures of flexible pavements can occur due to the failure of one of the four layers. Failure of Sub-grade will result in the failure of the pavement, because it will get reflected in the top surface. Similarly failure of the sub-base or base layer will also result in the failure of the pavement. There are various causes of the failure of the flexible pavement, I will post another article for this. Here we will talk about the general failures that occur in the flexible pavements.

Alligator(Map) crackingShear FailureFrost HeavingLongitudinal crackingConsolidation failureWearing of the SurfaceReflection cracksAlligator Cracking: Alligator or map cracking occurs on the surface of the flexible pavement due to the relative movement of the material or failure of the materials of the pavement layers. This may be caused by the repeated application of the heavy wheel loads resulting in fatigue failure due to the moisture variations resulting in swelling and shrinkage of sub-grade an…

Accident Studies- Causes and Prevention (Highway Engg.)

Hi there,
In the syllabus for Highway Engineering(HPU) , this topic is under the section C of Traffic Studies. I have discussed the parking studies in my previous article and in this post I am going to post about the Causes and Prevention of the accidents.

Under the mixed traffic conditions and different types of man-oeuvres avoiding the accidents to 100% is not possible, but by studying the various causes and characteristics of the accidents we can provide some preventive measures or improvements to reduce the rates of the accidents.
In any accident there are four elements which take part in it:

Road UserVehicleRoadEnvironment. Road user may be a driver or a pedestrian. Generally driver becomes the cause of the accidents when he is in drunken state, tired, sleepy or in some temporary state of anger or grief. Pedestrians becomes the cause of accident when they are careless while crossing the roads.
Vehicle may becomes the cause of accident when its dynamic characteristics such a…

Parking Studies (Highway Engineering)

After teaching this topic of highway engineering to 1st batch of Civil Engineering at JNGEC Sunder Nagar, I thought to write a post about it.
Certainly, I have not lived in a big city such as Chandigarh,Mumbai or Delhi and more than that I have spent first 10 years at a mountain village of Himachal Pradesh and next years at its nearby district towns.
I love short distance travels and I feel good when I travel. I have not taken more than 2 days train journey but, that doesn't make me less curious to know more about Highway Engineering. Completing a four years degree in Civil Engineering was a totally different thing than to teach it.

In order to teach it I have to have a deep understanding of the subject matter. Now, let's come to the topic at the instant. Parking Studies are done to find out the present capacity and the demand of the parking in the area under study and thereby to suggest any kind of improvement to it.
I have seen that parking studies may not be important …