Factors Affecting Transportation The success of transportation engineering depends upon the co-ordination between the three primary elements, namely the vehicles, the roadways, and the road users. Their characteristics affect the performance of the transportation system and the transportation engineer should have fairly good understanding about them. This post elaborated salient human, vehicle, and road factors … Read more
Properties of Concrete in Plastic State 1. Essential Qualities The quality of the hardened concrete is largely dependent on the quality of the plastic concrete. The curing process also contributes to attainment of the specified design criteria. Because the consistency of the mix may vary, careful adherence to design criteria is extremely important. When the … Read more
Types of Concrete Pavement In pavement construction, three different concrete pavement design types are commonly used: Jointed Plain Concrete Pavements (JPCP), Jointed Reinforced Concrete Pavements (JRCP), and Continuously Reinforced Concrete Pavements (CRCP) Each of these design types can provide long-lasting pavements that meet or exceed specific project requirements. Each type is suitable for new construction, … Read more
Aggregates for Asphalt Concrete The amount of aggregates for asphalt concrete mixtures is generally 90 to 95 percent by weight and 75 to 85 percent by volume. Aggregates are primarily responsible for the load supporting capacity of a pavement. Aggregate has been defined as any inert mineral material used for mixing in graduated particles or … Read more
Essential Properties of Asphalt Concrete Mix design methods and design requirements form an essential part for all asphalt concrete mixtures. The agency or authority responsible for paving construction (Department of Transportation) usually establishes the mix design method and design requirements. Once these are established, it becomes the responsibility of the Contractor/Producer and his technician to … Read more
Joints in Rigid Pavement Provisions of joints are necessitated due to: 1) Expansion, contraction and warping of concrete slabs resulting from temperature and moisture changes; 2) Facilitate a break in the construction at the end of day’s work or for any unexpected interruption to work progress; and 3) Construction of pavements in lanes of convenient … Read more
Failure of Rigid Pavement Failure in rigid pavement (or cement concrete pavement) can be identified by formation of cracks on the pavement surface. The two prime factors responsible for rigid pavement failure are Use of poor quality material Inadequate stability of the pavement structure Poor quality of material consist of following items Using soft aggregate … Read more
Failure of Flexible Pavement A typical flexible pavement consist of following 4 layers Soil subgrade Sub-base course Base course Surface or wearing course If due to any reason, any of the above mentioned layers loses its stability, it will lead to failure of the whole pavement. There are many types of failures of flexible pavement, … Read more
Terminologies Related to Pavement Materials ABRASION The abrasion test measures the abrasion or wear and tear resistance of the aggregate. The test is performed in the Los Angeles drum which is charged with a given weight of aggregate meeting one of the sieve grading. The drum containing the charge and the abrasion steel balls is … Read more
Repair of Potholes Potholes are the most frequent type of failure found in bituminous wearing surfaces. Potholes may be caused by defective drainage, frost action in the base, settlement of the base, or heavy traffic. A small pothole may be’ surrounded by a large area that is progressively failing. A pothole may be repaired with … Read more