Category Archives: DEFINATIONS

DEFINATIONS

BASICS DEFINATIONS

Leave a comment

CIVIL_ENGINEERING

  • Height of drop of concrete,  is also an important aspect to be considered because if the drop height  is more than 1 meter segregation would happen and result in reduction  of concrete strength.
  • Use of stirrup is to  handle the shear force and to hold the re-bars in position. The vertical member in  truss is similar to stirrup in beam and  compression member in truss is  similar to concrete between the  stirrups. you are aware that concrete is  good at compression and steel  is good at tension, thus the combination  of both counters the shear  force.
  • Aggregates, used  for concrete production should be less pores,  in other words it should  not absorb water more than recommendations by Code’s, usage of such  aggregates would reduce strength by absorbing water from concrete.
  • When concrete is setting (gaining strength) lot of heat is generated, in  order to compensate the water loss due to the heating action water is  added externally. Curing , is very  important point in concrete works, if proper curing is not done the  result would be crack formation & reduction in strength.
  •   Shuttering or form work should be strong enough to support the weight  of wet concrete mix and the pressure for placing and compacting concrete  inside or on the top of form work/shuttering. It should be rigid to  prevent any deflection in surface after laying concrete and be also  sufficient tight to prevent loss of water and concrete. Shuttering  should be easy in handling, erection at site and easy to remove when  cement concrete is sufficient hard.
  • Building Configuration :An important feature is regularity and  symmetry in the overall shape of the building. A building shaped like a  box, such as rectangular both in plan and elevation is inherently  stronger than one that is L-shaped or U-shaped such as a building with  wings.
  • Separation of Blocks:Separation of a large building into several  blocks may have to be done in order to obtain symmetry and regularity of  each block. Separated sections can be treated just like expansion  joints.
  • Adverse Elements: Even before the construction commences, it is  essential to check for certain adverse factors whose existence would  necessitate the abandonment of that particular site for construction.
     1. Immediate neighbourhood of rivers carrying heavy floods.                   2. Reclaimed soils; land subject to subsidence or settlement                          
    3. Smoke or obnoxious odour due to vicinity to industrial areas                          .
  • The construction site should not be a part of a land  depression. The topographical conditions of a site not only determine  its elevation and foundation, but also affect the laying of sewers and  drains.
  • Geological Conditions:The geological conditions of the site are also  important factors to be considered due to their effect on the  foundation and the subsequent life and strength of the construction. If  there is a rocky base on the surface or below, the site is optimum as it  provides an excellent base for laying the foundation and also prevents  damage due to moisture.
  • Orientation: In northern India, longer walls are generally  placed towards north & south and shorter walls towards east &  west, so that minimum possible walls are exposed to the sun. The general  wind direction of the site also determines the orientation of the  building.
  • Plinth: It is a good practice to keep plinth level 60 to 75 centimetres above natural ground level.
  • Damp Proof Course: Provide a Damp Proof Course (D.P.C.) at plinth  level in cement concrete by adding water -proofing compound in the  ratio 1 : 2 : 4.
  • R.C.C. Bands: Provide R.C.C. bands at sill, lintel and roof  levels for load bearing constructions for earthquake-resistant.
  • Brick Masonry:
    • Soak the red bricks in clear water thoroughly before use.
    • It is desirable to provide expansion joints after every 30 meter length of wall.
    • Half brick masonry wall should be reinforced with suitable reinforcement at every third or fourth course of wall.
  • Buy low-maintenance building materials — vinyl siding and metal  roofing,   for example. Even if they are somewhat more expensive at  installation, they   will pay for themselves in the long run as you  won’t have to repair, replace,   or repaint.
  • Over finishing is the major cause in surface deterioration, therefore  do not overwork the surface. Not only is it time consuming and  expensive, but tends to bring too much fine material to the surface and  weaken it. Never use a steel trowel on concrete exposed to weather.
  • I-Section: It is very good for  giving stiffness(less deformation on loading) and to withstand higher  bending moments(as a result of heavy loading) on comparison with other  cross-sectional shapes of same area. Also, it is very easy to  manufacture. It will have more moment of inertia due to the  distance of the flange from the centroidal axis and it have zeron  eccentricity about one axis and the centrer of gravity lies inside the  web.