Quality Requirements of Drinking Water Parameter Requirements (Desirable Limits) Undesirable effect when outside permissible limit Permissible limit in the absence of alternate source ESSENTIAL CHARACTERISTIC pH 6.5 – 8.5 Beyond this range the water will affect the mucous membrane and/or water supply system No relaxation Colour (Hazen units), maximum 6.5 – 8.5 Above 5, consumer … Read more
Depth of Soil Exploration The object of site exploration is to provide reliable, specific and detailed information about the soil and ground water condition of the site which may be required for a safe and economic design and execution of the engineering work. Dr. B.C. Punima Generally soil exploration should be advanced to a depth … 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
ABSOLUTE VISCOSITY TEST OF BITUMEN Reference IS: 1206 (Part 2) – Method for Testing Tar and Bitumen Materials: Determination of Absolute Viscosity Test Equipment The following testing equipment is needed to measure absolute viscosity of viscosity graded paving bitumen (IS:73-2006) at 60 C in accordance with IS:1206 (Part 2) (similar to ASTM D 2171), which … 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
Concrete Repair Chemicals Chemicals that are used to repair damaged sections or members of any concrete structure is called concrete repair chemicals. Concrete repair chemicals are of various types. While some are used for increasing bond strength between old concrete and new concrete; others are used for water repellant or corrosion resistance purpose. Depending upon … Read more
Geo-technical Engineering Terms Absorbed water Water held mechanically (by surface tension) in a soil mass Activity Ratio of the plasticity index to the clay fraction Adhesion Shearing resistance between soil and another material under zero externally applied pressure Adsorbed water Water in a soil mass, held by physio-chemical forces, having physical properties are substantially different … Read more
Definition – What is Bitumen Emulsion? Bitumen emulsion is a mixture of water & bitumen. Hey wait, we know that bitumen is a oil product and it cannot be mixed with water. That is why we add an emulsifier (a surface active agent) with water before adding bitumen. Addition of emulsifier with water facilitates breaking … Read more
Types of Rollers Depending upon the project requirement and soil to be compacted, different types of rollers are used for compaction work. The various types of rollers which are used for compaction are: Cylindrical Rollers Sheepsfoot Rollers Pneumatic tyred Rollers Smooth wheeled Rollers Vibratory Rollers Grid Rollers The following types of road rollers are generally … Read more