Protect Yourself from Silica Dust Silica dust, known as crystalline silica, is a naturally occurring mineral found in various rocks, sand, and soil. It is commonly encountered when working with concrete, mortar, stone, brick, and asphalt. Silica dust is generated by cutting, drilling, grinding, or crushing these materials. Silica consists of tiny crystalline particles of … Read more
Admixtures are substances which when added to concrete in small doses can overcome some of the drawbacks viz., poor workability, high shrinkage cracks, poor performance against chemicals, high permeability, inadequate protection of steel reinforcement from corrosion, low tensile strength and lower fracture toughness. Admixtures can be defined as materials other than water, cement and aggregate, … Read more
PROPERTIES OF HARDENED CONCRETE The following are the properties of concrete in its hardened state, used by the designer during design process of reinforced concrete structure. 1. Compressive Strength The characteristics strength is defined as the strength of concrete below which not more than 5% of the test results are expected to fall. As per … Read more
Portland Pozzolana Cement 1. Pozzolana Pozzolana is a volcanic powder found in Italy near Vesuvius A pozzolanic material is essentially a siliceous or aluminous material which possess no cementitious properties. But it has the property when it combined with lime to produce a stable pozzolana compound it has definite cementitious properties. In the presence of … Read more
What Is Volume Batching of Concrete? Batching of concrete means measuring different ingredients of concrete (i.e. cement, sand, coarse aggregate and water) before mixing it. When this measurement is done on the basis of volume, we call it Volume Batching. Below are mentioned some of important points to remember before adopting volume batching method in … Read more
Needle Vibrator These concrete vibrators are also referred to as poker or immersion vibrator. These are extensively used in building industry. A needle vibrator consists of a cylindrical casing made of steel and is vibrated by means of a flexible drive with an outer tube run from an operating machine which can be run by … Read more
Comparison between Ordinary & Performance Graded Binders The primary differences between ordinary graded binder and performance graded binder is given in the following table Ordinary Graded Binders Performance Graded Binders Binders are graded either based upon penetration or viscosity Binders are graded based upon pavement temperature, which are close to in service conditions of pavements … Read more
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
Different Forms of Bitumen 1. Cutback Bitumen Normal practice is to heat bitumen to reduce its viscosity. In some situations preference is given to use liquid binders such as cutback bitumen. In cutback bitumen suitable solvent is used to lower the viscosity of the bitumen. From the environmental point of view also cutback bitumen is … Read more
Processing of Borrow Area Soils / Backfill Materials The construction of subsurface structures often requires the construction of elements of the structure within or upon large masses of backfill. The proper functioning of these elements are often critically affected by adverse behavioral characteristics of the backfill. Behavioral characteristics are related to material type, water content … Read more