What is Ballast? The granular material i.e. broken stones, shingles, gravels, etc., placed below and around the sleepers, to transmit wheel load from sleepers to formation and also to provide proper drainage, is called ballast. What Are the Functions Ballast in Railway Track bed? The primary reasons for using ballast are as follow: It provides … Read more
WATER BOUND MACADAM The concept of water bound macadam road was suggested by John Macadam, who was a Scottish engineer. The road whose wearing course consists of clean crushed aggregates, mechanically interlocked by rolling and bound together with filler material and water laid on a well compacted base course, is called water bound macadam (W.B.M) … Read more
A FIGHT AGAINST TRAFFIC Congested roadways are common problems that all drivers have to deal with. Whether commuting to work or enjoying a leisurely drive through the city, it is a problem that causes a great deal of stress and unnecessary frustration. However, while it is still a large problem, many engineers are dedicating their … Read more
The surface course is the uppermost structural layer in an asphalt pavement. In most cases it is the top layer of the pavement and also serves as the wearing course. Since it is directly exposed to traffic and environmental forces, it must be produced with highest quality material. Characteristics of Surface Course The surface course … Read more
Optimum Binder Content in Bituminous Pavement The amount of binder to be added to a bituminous mixture cannot be too excessive or too little. The principle of designing the optimum amount of binder content is to include sufficient amount of binder so that the aggregates are fully coated with bitumen and the voids within the … Read more
Importance of Air Void in Flexible Pavement The air void content of bituminous materials is an important control parameter for the quality of bitumen being laid and compacted. If the air void content is too high, it allows for intrusion of air and water. Moreover, it also increases the rate of hardening of binders which … Read more
Function of Road Base and Base Course Road base is the most important structural layer in bituminous pavement. It is designed to take up the function of distributing the traffic loads so as not to exceed the bearing capacity of subgrade. In addition, it helps to provide sufficient resistance to fatigue under cyclic loads and … Read more
What is Contraction Joints ? Contraction joints are planes, usually vertical separating concrete in a structure or a pavement placed at a designed location. Contraction joint is placed in such a way that it interferes least with the performance of the structure as well as prevents formation of objectionable shrinkage cracks elsewhere in concrete. Why … Read more
The role of a consultant is not to find faults but to suggest and implement suitable remedial measures and to assist in achieving quality workmanship during the course of execution. Consultants generally follow the following checklist to ensure the quality of the cement concrete pavement during the time of construction. Ensure that mix design is … Read more
Overview Mobility is a basic human need. From the times immemorial, everyone travels either for food or leisure. A closely associated need is the transport of raw materials to a manufacturing unit or nished goods for consumption. Transportation ful lls these basic needs of humanity. Transportation plays a major role in the development of the human civilization. For … Read more