Types of Failures of Flexible Pavement Flexible pavement consist of different layers such as, Sub-grade Sub-base course Base course and Surface course If any one of the above mentioned layers becomes unstable or weak then it will result in failure of flexible pavement. Therefore it is very important to design and construct each layer with … Read more
Factors Affecting Pavement Design Several factors affect pavement design, the most important being wheel load. Since pavements are designed to take moving loads, slow moving loads and static loads can be detrimental to the pavement. Temperature also influences pavement design especially the frost action which is very important in cold countries. There are many factors … Read more
WBM Road Construction Procedure Construction of water bound macadam road involves the following 6 basic steps as given below. Preparation of sub-grade Preparation of sub-base Preparation of base Preparation of wearing course Preparation of shoulders Opening to traffic Step – 1 (Construction of Sub-grade) Sub-grade act as a cushion for other layers i.e. In order … Read more
Different Ways To Clean Clay Paved Surface Clay paving provides a durable, hardwearing surface but, like any surfacing material, this may suffer from time to time from staining, due to general trafficking and contamination from other sources. Due to the nature of construction, there may also be some vegetation growing in the joints, or on … 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
Aggregate impact value test gives an indication of aggregate’s toughness property (i.e. property of a material to resist impact) Aggregate impact values are used to classify the stone aggregates with respect to toughness property as given below. Aggregate impact value (%) Toughness Properties <10 Exceptionally tough / Strong 10 – 20 Very tough / Strong … 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