1. Item rate contract This is also known as Unit price contract. In this contract, contractor quotes his rates for per unit of each item of construction. Bill of quantities is prepared as accurately as possible. Certain reasonable variations in the quantities being accepted by both the parties. Most of the public works are carried out under this form of the contract. 2. Percentage rate contract Department draws up the schedule of items according to the description of items sanctioned in the estimate with the quantities, units, rates and amounts…
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What is Contract ? Requirements of Valid Contract ?
Contract : It is an understanding or agreement by a person or a firm to do any work under certain terms and conditions. The work may be for the construction, maintenance & repair, for the supply of materials, for the supply of labor, etc. A contract is an agreement which can be enforced by law. In order to make this agreement valid, there must be a definite offer and equally definite and unconditional acceptance of this offer. As per The Indian Contract Act, of 1872 section 2(a), Proposal : When…
Supports & Their Reactions
1. Fixed support : there can be three reactions One vertical reaction One horizontal reaction One moment reaction 2. Hinge/Pin support : there can be two reactions One horizontal reaction One vertical reaction 3. Roller support : there can be one reaction only One vertical reaction 4. Rocker support : there can be one reaction only One vertical reaction
Working Stress Method
This is the traditional method of design, used not only for reinforced concrete but also for structural steel and timber. This method of designed was evolved around the year 1900. This method was accepted by many national codes. India’s code IS:456-1953 was based on this method. It was revised in 1957, 1964, 1978, 2000 and reaffirmed in 2005 and its tenth reprint was in 2007. This method is based on linear elastic theory. This method ensures adequate safety by suitably restricting the stresses in the materials induced by expected working…
Limit State Method
In this method of design, the is designed to withstand the safety of for all loads liable to act on it throughout its life, it also satisfied the serviceability requirements such as limitation on deflection and cracking. The aim of design through this method is to achieve acceptable probabilities that structure will become unfit for use to which it is built. It means that it will not reach a limit state or critical state. All relevant limit states should be considered in design to ensure an adequate degree of safety…
Basic Knowledge for every Civil Engineer
This is the very basic and important knowledge that every civil engineer must have. It can be useful at various places of technical as well as practical field. CONCRETE GRADES WITH THEIR MIX PROPORTIONS:M-5 = 1:4:8M-10= 1:3:6M-15= 1:2:4M-20= 1:1.5:3M-25= 1:1:2 CONSIDERATION OF CLEAR COVER TO MAIN REINFORCEMENT:1.FOOTINGS : 50 mm2.RAFT FOUNDATION.TOP : 50 mm3.RAFT FOUNDATION.BOTTOM/SIDES : 75 mm4.STRAP BEAM : 50 mm5.GRADE SLAB : 20 mm6.COLUMN : 40 mm7.SHEAR WALL : 25 mm8.BEAMS : 25 mm9.SLABS : 15 mm10.FLAT SLAB : 20 mm11.STAIRCASE : 15 mm12.RETAINING WALL : 20/ 25…
Rules and Criteria for measurement of Plastering
Rules for Deduction : No deduction shall be made for openings less than 0.5 sq m in area, and no addition shall be made reveals, jambs, soffits, sills, etc. of these openings. No deduction shall be made for ends of joists, steps, etc. not exceeding 0.5 sq m in area. For openings exceeding 0.5 sq m but not exceeding 3 sq m and when both faces are plastered with same type of plaster each deduction shall be made for one face only, and the other face shall be allowed for…
Contingencies & Work charged Establishment
Contingencies The term “contingencies” indicates the incidental expenses of miscellaneous character which cannot be classified under any distinct item sub-head, yet pertain to the work as a whole. To meet such unforeseen expenses an additional amount of 3% to 5% of the estimated cost of the works is provided in the total estimate. Miscellaneous incidental expenses which cannot be classified under any sub-head or item, are met from the amount provided under contingencies. For example, suppose there is an item in estimate for cement plastering 1:4 with neat cement finish,…
Long wall-Short wall method: Estimation up-to Plinth level
Learn how to estimate and calculate various quantities of sub-structure or structure up-to plinth level which includes; Excavation for foundation P.C.C in foundation Brick work in foundation. Its very simple to calculate theses all the quantities using long wall-short wall method. You will easily understand this method after studying this PDF file given below. For better explanation, you can also watch videos on our YouTube channel “Technical CiViL”.
Modified Moment
What is Modified Moment ? Modified moment is generally considered or calculated where there is more than one moment acting at a point or on a span. Let suppose there are two moments acting on a span having opposite nature. It means that we are supposing that if the moment is in clockwise direction, it will be +ve and anticlockwise will be -ve. Now since these two moments are having opposite nature, they will cancel out each other up-to some extent. Now point to be noted here that, always bigger…