Preparation and Applications of Paints
Paint can be applied as a solid, a gaseous suspension (aerosol) or a liquid. Techniques vary depending on the practical or artistic results desired. As a solid (usually used in industrial and automotive applications), the paint is applied as a very fine powder, then baked at high temperature. This melts the powder and causes it to adhere (stick) to the surface. The reasons
What is Plaster of Paris and How to Make it at Home?
Plaster of Paris is a Calcium sulfate semi-hydrate (CaSO4,½ H2O) derived from Gypsum, a calcium sulfate di-hydrate (CaSO4, 2H2O), by firing this mineral at relatively low temperature and thus reducing it to powder. In 1700’s, Paris was already the “Capital of plaster” since all the walls of wooden houses were covered with plaster, as a protection against fire. The King
Manufacturing and Uses of Portland Cement
Cement can be defined as the bonding material having cohesive & adhesive properties which makes it capable to unite the different construction materials and form the compacted assembly. Ordinary/Normal Portland cement is one of the most widely used type of Portland Cement. The name Portland cement was given by Joseph Aspdin in 1824 due to its similarity in
Methods of Natural Seasoning of Wood
The basic principle is to stack the timber so that plenty of air can circulate around each piece. The timber is stacked with wide spaces between each piece horizontally, and with strips of wood between each layer ensuring that there is a vertical separation too. Air can then circulate around and through the stack, to slowly remove moisture. In some cases, weights can be placed
Process of Steel Manufacturing
The first step in the steel manufacture begins at the blast furnace. To separate iron from iron ore â–ş coke (substance when gas is taken out of coal), limestone and dolomite are charged into the blast furnace. Temperature raised to 1600oF. This high temp causes the coke to burn and melt the iron. This red hot iron drained at an opening at the base of the furnace. Natural
Types of Metals used in Civil Engineering
All metals used for engineering works are classified into Ferrous metals: A) Ferrous metals: Wherein iron is the main constituent (Cast iron, wrought iron and different forms of steels) Ferrous metals â–ş not directly obtained from iron ores Non-Ferrous metals: Wherein iron is not the main constituent (Copper, Aluminum, Zinc and lead etc)
What is Varnish and Types of Varnishes
Varnishes are more or less transparent liquids which are used to provide a protective surface coating in much the same way as paints do” At the same time they allow the original surface to show but add a lustrous and glossy finish to it. All varnishes have basically the same
What are GeoTextiles & GeoSynthetics?
In only a very few years, geosynthetics (geotextiles, geogrids, and geomembranes) have joined the list of traditional civil engineering construction materials. Often the use of a geosynthetic can significantly increase the safety factor, improve performance, and reduce costs in comparison with conventional construction alternatives. In the case of embankments on extremely
Types of Bitumen and Importance of Bituminous Materials
Bitumen is an essential component of any pavement and is used widely throughout the world. It can be termed as the building block of the pavements without which all the pavement materials would behave independently and thus will be deemed useless. Almost ninety percent of bitumen is used in road construction. It is usually available in dark colors ranging from brown
How and When to Paint and its Purpose
Before painting, wood siding and trim should be treated with a paintable water-repellent preservative or simple water repellent. This can be done by brush after the siding or trim is up, or by dipping before it’s installed. If you work by brush, all lap and butt joints in solid wood or all panel edges should be especially well saturated. Allow at least two warm, sunny days for
What is a Premix and Types of Premix
Something that is mixed or blended from two or more ingredients or elements before being used. This term is used usually for concrete in civil engineering. Sheet Asphalt: A premix of bitumen and sand (with or without filler) and containing coarse aggregate that exceeding 30%, laid in thickness varying from ¾" to ½" (dense carpet, stone metal is discarded and
Properties of Bitumen and Bituminous Materials
Adhesion: Binds together all the components without bringing about any positive or negative changes in their properties. Bitumen has the ability to adhere to a solid surface in a fluid state depending on the nature of the surface. The presence of water on the surface will prevent adhesion. Resistance to Water: Bitumen is insoluble in water and can serve as an
Chemical and Physical Composition of Bitumen
Coal tar is a brown or dark black liquid of high viscosity, which smells of naphthalene and aromatic hydrocarbons. Being flammable, coal tar is sometime used for heating or to fire boilers. It can be used in coal tar soap, and is used in medicated shampoo to kill and repel head lice, and as a treatment for dandruff. Depending upon its source of origin, TAR is classified as:
Decay & Preservation of Wood & Timber
The principal destroyers of wood are decay, caused by fungus, and attack by a number of animal organisms of which termites, carpenter ants, grubs of a wide variety of beetles, teredo, and limnoria are the principal offenders. In addition, fire annually causes widespread destruction of wood structures. Decay will not occur if wood is kept well ventilated and air-dry or
