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Showing posts from May, 2020

clearing and grubbing (tree cutting and it's measurements) , Dismantling culverts, bridges and other structures / pavements (bituminous road/ Concrete pavements), backfilling and its measurements etc.

Site clearance Work - A - CLEARING AND GRUBBING(CnG)  1 - Scope This work shall consist of cutting, removing and disposidg of all materials such as trees, bushes, shrubs, stumps, roots, grass, weeds, rubbish, top organic soil, etc. to an average depth of 150 mm in thickness, which in the opinion of the Engineer are unsuitable for incorporation in the works, from the area of road land containing road embankment, drains, cross-drainage structures and such other areas as may be specified on the drawings or by the Engineer. It shall include necessary excavation, backfilling of pits resulting from uprooting of trees and stumps to required compaction, handling, salvaging, and disposal of cleared materials with all leads and lifts. Clearing and grubbing shall be performed in advance of earthwork operations and in accordance with the requirements of these Specifications. 2 -Preservation of Property/Amenities Roadside trees, shrubs, any other plants, pole lines, fences

Surface finish and quality control of work [Tolerance of horizontal alignment (edge tolerance), surface level tolerance (Tolerance in Reduced level), surface regularities and irregularities, rectification (sub grade, GSB, WMM, DBM/BC, DLC, PQC) and riding quality of pavement ]

Surface finish and quality control of work:- This article includes Tolerance of horizontal alignment (edge tolerance), surface level tolerance (Tolerance in Reduced level), surface regularities and irregularities, rectification (sub grade, GSB, WMM, DBM/BC, DLC, PQC) and riding quality of pavement A- Horizontally alignments Horizontally alignments shall be reckoned w.r.t. the center line of the carriageway as shown on the drawings. The edge of the carriage way as constructed shall be correct within a tolerance of ±10 mm there from. The corresponding tolerance for edges of the roadway and lower layer of pavements shall be ±25 mm. B- Surface Level  The levels of the subgrade and different pavements courses as constructed, shall not vary from those calculated with reference to the longitudinal and cross-profile of the road shown on the drawing or as directed by the engineer beyond the tolerance mentioned in table below(table 900-1). Provided, however, that the negati

Dense Bituminous Macadam (DBM) or Bituminous Concrete (BC) layer Quantity / Compaction Factor value / Loose thickness calculation

Dense Bituminous  Macadam (DBM) or   Bituminous Concrete (BC)  quantity / Compaction Factor value for DBM or BC / Loose thickness of DBM or BC Layer  In this article we shall discuss three important points about Dense Bituminous   Macadam (DBM) or Bituminous Concrete (BC) 1- How can we calculate the required DBM/BC quantity?  2 -  What is value of compaction factor for DBM/BC? 3- How much loose thickness should be taken to get proper compacted layer thickness ?  1- How can we calculate the required DBM/BC quantity? Let us consider Length of  DBM/BC layer (L) = 1 Km = 1000 Met. Breadth of DBM/BC Layer (B)= 5 Met. Thickness of DBM/BC Layer (T)  = 50 mm =0.050 Met. Max. Dry Density (MDD) =2.441 Gram/ Cubic Centimeter = 2441KG/ Cubic metre Note  -  The value of MDD is calculated by conducting suitable test . Then Volume of DBM/BC Layer = ( Length of DBM/BC layer X Width of DBM/BC layer  X Thickness of DBM/BC Layer) Volume of DBM/BC Layer = L X B X T Volume o

Bituminous Concrete (BC) specifications viz. Layer thickness, Mix and material requirements, grading , laying trials, Rolling , Construction procedure, transport and joint specifications, surface finish and quality control,measurement and rate per MORTH and Indian Standard

Bituminous concrete(BC)- Bituminous concrete( BC) is used for wearing  course and profile corrective courses.BC is generally laid in single layer on a previously prepared bituminous bound  surface. The thickness of single layer of BC shall be 30mm,40mm and 50mm. 1 -MATERIAL A- Bitumen - The bitumen shall be viscosity graded paving bitumin complying with IS 73 or specified in contract aggrement. The type and grade of bitumen to be used would depend upon the climatic condition and the traffic. Selection criteria of viscosity graded (VG) paving bitumens based on climatic conditions B- Coarse Aggregate It consist of crushed rock,crushed gravel or other hard material retained on 2.36 mm sieve. It shall be clean ,hard,durable and of cubical shape,free from dust,and  soft organic and other deleterious substances. The aggregates  shall satisfy the physical requirements of table  no. -2 (Table no. 500-16 ,as per MORTH 5th revision) where crushed gravel is proposed 

Water quantity / Volume of water calculation for the beds of Embankment/subgrade/GSB as per MORTH and Indian Standard

Water quantity calculation for the beds of Embankment/subgrade/GSB as per MORTH and Indian Standard Welcome friends Today we shall know about the calculation of water required for the beds (Embankment/sub-grade/GSB) to achieve the desired compaction Let us consider We want to calculate the water quantity for the bed of sub-grade so....... Let us consider Width of sub-grade bed (B)  = 8 metre Thickness of sub-grade  layer(T) = 0.200 metre Length of sub-grade bed(L) = 500 metre Optimum moisture content (OMC) = 12 % Then Volume of sub-grade bed = length X width X thickness  = L X B X T             = 500 X 8 X 0.200             = 800 cubic met. Let Moisture present in bed(it may be zero) = 4 % (Note-  Data of Moisture present in bed is calculated by lab team by rapid moisture metre or by using any other equipment ) Moisture required  to get desired compaction in bed of sub-grade= OMC - Moisture present in sub-grade bed   = 12 - 4 =8% (Note- Minimum com

Work Capacity (output, efficiency) of Road Construction equipment / Machines and their work efficiency

Work Capacity (output, efficiency )  and Name of various types equipments used in road construction,Railways work, Building works and other construction areas. 1- Motor Grader Let us assume  Speed of motor grader during working                            = 4 Km / Hour = 4000 Met/ Hour Width of Blade                =         3.66 Met. Layer Thickness       =          0.200 Mtrs. Number of Passes           =          4    efficiency factor                  =   80 % Capacity  = (4000 X 3.66 X 0.80 X 0.200) /4 = 585.6 Cum /Hour 2- Excavator Volume of bucket                   =          1.02Cum Cycle Time during operation =          30 Sec.                               = 30/3600= 0.00833 Hour Efficiency Factor              =          85% Capacity = (1.02 X 0.85) / 0.00833 = 104.081Cum / Hour  3- Wheel Loader Volume of bucket.   =    1.20 Cum Cycle Time During plant operation  =          2 Minute = 2/60 =  0.0333 Hour Efficiency  Facto