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Showing posts from February, 2019

Wet Mix Macadam (WMM) technical specifications as per MORTH and Indian standard in Civil engineering

WET MIX MACADAM (WMM) sub – base /base:- Wet mix macadam (WMM) act as a base course just below the bituminous layer (bitumen base course or surface course).  The thickness of a single compacted Wet mix macadam(WMM)  layer shall not be less than 75mm.when vibrating or other approved types of compacting equipment are used, the compacted depth of a single layer of the sub-base course may be up to 200mm. How to calculate the loose thickness of WMM, compaction factor and quantity of WMM ? Kindly visit on below link 🔗 https://www.gyanofcivilengineering.com/2020/05/wet-mix-macadam-wmm-quantity-compaction.html Physical requirements   Material finer than 425 micron shall have plasticity index (PI) not exceeding 6. To determine this combined portion, the flaky stone from a representative sample should first be separated out. Flakiness index is weight of flaky stone metal divided by weight of stone sample. Only the elongated particles are separated out from

What should be done in the absence of lean concrete (PCC- Plain cement concrete ) below the footing

What should be done in the absence of lean concrete  (PCC- Plain cement concrete )   below the footing It is well known that the cover is provided below footing to protect Re-bar from direct contact with atmosphere. So we shall know about the cover provided to footing. The minimum thickness of cover to main reinforcement shall not be less than 50 mm for surfaces in contact with earth face and not less than 40 mm for external exposed face. However, where the concrete is in direct contact with the soil, for example, when a levelling course of lean concrete is not used at the bottom of footing,  it is usual to specify a cover of 75 mm. This allows for the uneven surface of the excavation. In case of raft foundation, whether resting directly on soil or on lean concrete, the cover for the reinforcement shall not be less than 75 mm. Thank you Gyan of engineering (Mukesh Kumar) 

Granular Sub base (GSB) specifications, GSB Grading, layer thickness, Water absorption, Physical requirements (like liquid limit, Plasticity index ,AIV), construction procedure or Rolling , measurement and treatment of GSB as per MORTH 5th revision and Indian standard in Civil engineering

Granular sub-base (GSB) SUB BASE (GSB)– The full form of GSB is granular sub base.it is being laid in road work because it plays two major roles 1- it works as  drainage layer 2- it provides a good sub base to laid base layer on it. How to calculate the quantity, compaction factor value and loose thickness of GSB? To know more information kindly visit on below link 🔗  www.gyanofcivilengineering.com/granular sub-base(GSB) Quantity. Material –     The material to be used for the work shall be natural sand, crushed   gravel, crushed stone, crushed slag, or combination thereof depending upon the grading required use of material like brick metal, kankar and crushed concrete shall be permitted in the lower sub base. The material shall be free from organic or other deleterious constituents. Grading III and IV shall be used in lower sub base. Grading V and VI shall be used as sub-base-cum-drainage layer. Where the sub-base is laid in two layers as upper sub-base and lowe

cover block information for various items of structure

Cover Block :- A cover block is used to provide space between re-bar and ground( outer surface) so that concrete may flow underneath the rebar. Rebars are fully encases in concrete to prevent corrosion. Sometimes binding wire is embeded in cover block to provide better holding and stability. Various types of cover block are used to creat gap between rebar and outer surface. Types of cover block 1-Cement masonry cover block 2-Wooden cover block. 3-Polyvinyl chloride (PVC)  cover block 4- Steel cover block 5-Stone cover block 6-Aluminum cover block SECTION 'A' Reinforcement shall have concrete cover (nominal) and the thickness of such cover (exclusive of plaster or other decorative finish) shall be as follows: To know more about the RCC column specifications, please click on below link 🔗  https://www.gyanofcivilengineering.com/2019/09/specification-of-rcc-reinforced-cement.html 1- At each end of reinforcing bar not less than 25 mm, or twice the diam

Detailed calculation to calculate the volume of one cement bag in cubic metres /litres/ cubic feet

Detailed calculation to calculate the Volume of 1 cement bag   Cement play a major roll in construction  work. It acts as a binder that sets, hardens, and adheres to other materials to bind them together. Here we shall learn whole process how can we calculate the volume of 1 bag of cement. We know that Mass= volume × Density Then Volume = mass /Density We also know that Density of cement = 1440 kg/m^3 Weight of 1 cement bag = 50 KG Putting the values in the formula Volume = mass /Density Volume of one cement bag = 50/1440 cubic metre Vol. of one cement bag = 0.03472 cubic metre  Volume of one cement bag can be given in litre We know that 1 cubic metre= 1000 litre Then Volume of one cement bag = 0.03472 × 1000 Vol. Of one cement bag  = 34.72 litres Volume of one cement bag can be given in cubic feet We know that 1 cubic metre = 35.315 cubic feet Then Volume of one cement bag = 0.03472 cubic metre      = 0.03472 × 35.315 cubic feet      Vol. Of one

How to calculate the weight steel bar with example OR derivation of formula   ( D²/162.131)-

In this article we shall discuss   1 - Derivation of  D²/162.131 in details  2- How to calculate weigh of steel bar with example  We know that Mass = volume × Density Calculation to calculate the volume of steel bar - Length = 1 met. = 1000 mm Let us consider that the steel bar is of circular shape. So Area of bar =  ( π/4)× D² square mm                                                        Where 'D' is diameter of steel bar in millimetre ("Diameter is considered in mm because steel bars come with diameter specified in millimetre in market. Viz. 8mm Φ, 16 mmΦ, 20mm Φ") Then Volume of bar= length of bar ×area of bar = 1000×(  π /4) × D ² = 1000 x ( π/4) D² cubic mm                                            To convert the volume in cubic metre from cubic mm We know that 1 cubic mm =   10^(-9) cubic metre        =             1                   cubic metre         (1000× 1000 ×1000) Then volume in cubic metres can be c

Rolling pattern and process, number of rolling passes, speed of roller(Soil compactor and tandem) , precautions During rolling operation of various road layers as per MORTH and Indian standard

This article includes 1-What is Rolling  and why rolling is required in road construction 2- Type of roller (soil compactor and tandem) 3-Process of rolling and speed of roller 4 Required number of rolling passes and Rolling pattern 5-Precautions during rolling 1-What is Rolling  and why rolling is required in road construction  Rolling means pressing the particles close to each other. Air during Rolling is expelled from the void space in the soil mass and, therefore, the mass density is increased. Rolling of a soil mass is done to improve its engineering properties. Rolling is an artificial process to achieve compaction in any required road layers. which is done to increase the density (unit weight) of the soil to improve its properties before it is put to any use. 2- Type of roller  Roller are generally divided in two A- Tandem B- Soil compactor Rolling is done with the help of roller (soil compactor and tandem).Generally plain roller and vibratory  Rolle