CIVIL ENGINEERING

                                                                               Fresh Concrete          An artificial stone-like material used for various structural purposes. It is made by mixing cement and various aggregates, such as sand, pebbles, gravel, shale, etc., with water and allowing the mixture to harden by hydration. Portland cement is the mostly used cement for the production of  concrete . It is the most popular artificial material. Probably It is used more than any other man-made product in the world. Usages of Concrete:   Cement is probably the most used man-made material. Concrete is used to make:       Pavements      architectural structures      foundations      motorways      roads and bridges      overpasses      parking structures      walls and footings for gates      fences and poles                                                                                                     

                                                                 Concrete Blocks  Followings are the types of blocks: Solid Concrete blocks Hollow concrete blocks Solid Concrete Blocks   It is is used for internal load-bearing walls and beam and block floor systems. A solid block is used in the form of a cavity or solid walls construction. Hollow concrete blocks  Hollow concrete blocks are one of the useful construction material, these are lightweight blocks and used for load-bearing on non-load bearing walls. In general practice, hollow concrete blocks are  30 cm X 20 cm X 15 cm ( 12inch x 8inch x 6 inch  )  in size. In general practice, for hollow concrete blocks, the face thickness must be at least 5 cm (2”)  and the net area must be 55 to 66% of the gross area. And the  mortar  used has a cement aggregate mix in  1:6 proportion . the blocks used for structural purposes should be at least  3 N/mm2( 450 lb /in2) Types of Hollow Concrete blocks  Stretcher (3core)  Double corner Low we

A concrete block is primarily used as a building material in the construction of walls. It is sometimes called a concrete masonry unit (CMU). A concrete block is one of several precast concrete products used in construction. The term precast refers to the fact that the blocks are formed and hardened before they are brought to the job site. Concrete blocks can be Solid or Hollow with two or three cores or voids. Concert Blocks are lightweight Generally it is used in high rise building to reduce structural load. Concrete blocks are easy to handle compare to red clay bricks, they are larger in dimension and superior in quality and most importantly save in time and cost. Concrete blocks are light and common in various sizes a standard concert block is 600mm x 250mm x 150mm is equivalent to by about 8 red clay bricks, the weight of one single block is about 14kg where is 8 red clay bricks is 36kg that is more than double. Concert blocks are easy to cut as the concert block surfaces are very

Sand  is a mixture of small grains of rock and granular materials which is mainly defined by size, being finer than gravel and coarser than silt. And ranging in size from  0.06 mm to 2 mm . Particles which are  larger than 0.0078125 mm  but  smaller than 0.0625 mm are termed  silt . Sand is made by erosion or broken pebbles and weathering of rocks, which is carried by seas or rivers. And freezing and thawing during the winter break rock up the sand will be made. Sometimes Sand on beaches can also be made by small broken-up pieces of coral, bone, and shell, which are broken up by predators and then battered by the sea, and even tiny pieces of glass from bottles discarded in the sea and other mineral materials or the bones of fishes or other oceanic animals. Sand can be also considered as a textural class of soil or soil type. A  sandy soil  containing more than 85 percent sand-sized particles by mass. Followings are the classification of Sand:   Based on the grain size of the particle,

13 Cements:- Ordinary Portland Cement (OPC) Portland Pozzolana Cement (PPC) Rapid Hardening Cement Quick setting cement Low Heat Cement Sulfates resisting cement Blast Furnace Slag Cement High Alumina Cement White Cement Colored cement Air Entraining Cement Expansive cement Hydrographic cement  Cement 1. Ordinary Portland Cement (OPC) Ordinary Portland cement is the most widely used type of cement, which is suitable for all general concrete construction. It is the most commonly produced and used type of cement around the world, with annual global production of around 3.8 million cubic meters per year.  This cement is suitable for all kinds of concrete construction. 2. Portland Pozzolana Cement (PPC) Portland pozzolana cement  is prepared by grinding pozzolanic clinker with Portland cement. It is also produced by adding pozzolana with the addition of gypsum or calcium sulfate or by intimately and uniformly blending Portland cement and fine pozzolana. This cement has a high resistance to

  Cement is a powder used to make concrete  Cement is a fine gray powder that is mixed with water and other substances to make mortar or concrete. It is a key building material in both residential and commercial construction work. CEMENT VS. CONCRETE The words cement and concrete are often used interchangeably. However, cement is actually an ingredient of concrete, not the final product. Cement is important becasue it binds, or holds, the concrete mix together, giving it strength . History of Cement Cement has been in use by humans throughout history; variations of the material were used by the ancient Greeks, Romans and Egyptians, with the earliest archaeological discovery dated to 12-10,000BC in modern-day Turkey. The Romans used a mixture of lime (calcium oxide) and pozzolan – crushed volcanic ash – to create hydraulic cements, which could set under water. Other cements used crushed brick, tiles and ceramic pottery as aggregates. Famous historical buildings made from concrete, still

D ifferent types of bricks are used in masonry construction based on material such as clay, concrete, lime, fly ash etc. Filed field identification of bricks for their properties, uses and suitability for different construction works are important.    Sun-Dried or Unburnt Clay  After molding, bricks are subjected to sunlight and dried using heat from sun. So, they are not that much strong and they also have less water resistance and less fire resistance. These bricks are not suitable for permanent structures. 2. Burnt Clay Bricks First class bricks Second class bricks Third class bricks Fourth class bricks First Class Bricks First class bricks are good quality bricks compared to other classes. They are molded by table-molding and burnt in large kilns. So, these bricks contain standard shape, sharp edges and smooth surfaces. They are more durable and having more strength. They can be used for permanent structures. However, because of their good properties they are costly than other clas