The composition and structure of flexible pavement consists of surface course, binder course, base course, subbase course, frost protection course, subgrade. Flexible pavements contain bitumen or asphalt layer as wearing course and supports loads through bearing. They have low flexural strength. Composition and Structure of Flexible Pavement Fig 1: Layers of Flexible Pavement 1. Surface Course…
A true flexible pavement yields “elastically” to traffic loading. It is constructed with a bituminous-treated surface or a relatively thin surface of hot-mix asphalt (HMA) over one or more unbound base courses resting on a subgrade. Group Index method of flexible pavement design is an empirical method which is based on the physical properties of…
Indian roads congress(IRC) has specified the design procedures for flexible pavements based on CBR values. The Pavement designs given in the previous edition IRC:37-1984 were applicable to design traffic upto only 30 million standard axles (msa). The earlier code is empirical in nature which has limitations regarding applicability and extrapolation. This guidelines follows analytical designs…
Flexible pavement design by CBR method is used to determine the total thickness of pavement. Generally there are two methods to design the pavement from CBR (California bearing ratio) value. They are 1. CBR method recommended by California state of highways 2. CBR method recommended by IRC CBR method recommended by California state of highways: Data required for…
Flexible pavements are so named because the total pavement structure deflects, or flexes, under loading. A flexible pavement structure is typically composed of several layers of materials. Each layer receives loads from the above layer, spreads them out, and passes on these loads to the next layer below. Thus the stresses will be reduced, which…
The Resilient Modulus (MR) is a measure of subgrade material stiffness. A material’s resilient modulus is actually an estimate of its modulus of elasticity (E). While the modulus of elasticity is stress divided by strain for a slowly applied load, resilient modulus is stress divided by strain for rapidly applied loads – like those experienced by pavements. Resilient modulus is determined using…
HMA pavements are flexible pavements. Flexible pavements are so named because the total pavement structure deflects, or flexes, under loading. A flexible pavement structure is typically composed of several layers of material each of which receives the loads from the above layer, spreads them out, then passes them on to the layer below. Thus, the further down in the pavement…
Pavement engineering is a branch of civil engineering that uses engineering techniques to design and maintain flexible (asphalt) and rigid (concrete) pavements. This includes streets and highways and involves knowledge of soils, hydraulics, and material properties. Pavement engineering involves new construction as well as rehabilitation and maintenance of existing pavements. Maintenance often involves using engineering judgment to make maintenance repairs…