1.0  Purpose

This provides details of Method Statement to be adopted for CTSB/CTB laying and compaction. For the functional requirement, the thickness of cement treated bases shall not be less than 100 mm.

2.0 Scope

This work shall consist of mixing, laying and compacting of aggregates mixed with cement in a mixing plant as a sub-base/base course on prepared subgrade/sub-base in accordance with the requirements of the Specifications and in conformity with the lines, grades and cross-sections shown on the drawings or as directed by the Engineer.

3.0  Equipment

Mixing Plant


Water Tanker



4.0    Mix Design

The aggregate gradation for CTB shall be as given in table 400-4 of MORT&H specification. The CTB material shall have a compressive strength of 4.5 MPa in 7 days. The minimum cement content for the mix shall be 2%. Mix shall be got approved by the engineer prior to its use.

5.0      Trial

A minimum 100-meter length of the new carriageway trial patch shall be laid with using hydraulic mechanical pave finisher.  Loose thickness of the layer, number of passes of vibratory roller to achieve 98 % modified proctor density, allowance for evaporation of moisture content, and line, level & cross fall shall be established during the trial. Before commencement of main work, trial patch should be got approved from the IE as per their satisfaction.

6. Responsibility

  • Section In charge will be responsible for quality control of the section for the construction CTSB/CTB. He will liaise with the Concessionaire Engineer In charge. Further he will be assisted by field engineers, surveyors, supervisors and lab technicians

7.0      Setting Out

 The limits of CTB layer shall be marked by fixing pegs on both sides at regular intervals.  The chainage boards & Bench Marks shall be set outside the limits of construction.

8.0      Procedure

Construction operation shall be as per Clause 403.3 of MoRTH or Chapter 5 of IRC SP 89. Before laying CTSB/CTB on already prepared sub base/sub grade , the shoulder shall be constructed first in order to provide confinement.

Material  for the CTSB/CTB shall be prepared as per mix design in mixing plant. Moisture shall be maintained within tolerance range as determined by Mix Design. The mix shall be spread by a paver finisher in full width of a pavement as per approved drawing. In exceptional cases where it is not possible for the paver to be utilized, mechanical means like motor grader may be used with the prior approval of the Engineer. Maximum care shall be taken to spread the material uniformly. The compaction shall be carried out as per clause 403.3.5 with the help of vibratory roller of 8T to 10 T. Rolling shall be continued until the density achieved is at least 98 percent of maximum dry density.

The sub-base/base course shall be suitably cured for 7 days. Subsequent pavement course shall be laid soon after to prevent the surface from drying out and becoming friable. No traffic of any kind shall ply over the completed sub-base/base unless permitted by the Engineer.

9.0  Quality Control and Testing

Quality control tests shall be done as per Quality Control Tests and Acceptance Criteria as set in MORT&H 5th revision. Of section 900.




Introduction : The purpose of this methodology is to measure physically the x section of the road on ground

Procedure :   The following procedure  to be adopted while taking physical measure :

  1. The sample shall be taken on random basis
  2. First lot of sample shall be taken by Independent Engineer
  3. Start from outer side
  4. First measure physically the width of drain
  5. Then measure the width of the service road, separator, main carriage way and median
  6. Continuously physically measure the length across the road width as stated above in each and every Km.
  7. Compare each with the required TCS

Precaution :

  1. Road should be barricaded by the safety cone
  2. Two flagmen should be deployed with red flag to direct the traffic



Introduction: The purpose of this  methodology is intended for the finding out the crust thickness along the road.

Procedure: The procedure of finding out the crust/Pavement composition are under :

  1. Decide the chainage from where the sample is to be taken on random basis
  2. The first pit shall be selected by the Independent Engineer
  3. Make a pit along the direction of the traffic in each stretch with regular interval of 5 km
  4. Make a suitable size of pit on shoulder along the movement of the traffic with the help of JCB
  5. After digging the pit measure the thickness of each component of the crust
  6. Compare this thickness from the original Crust design.
  7. Note down the thickness of each layer in prescribed format
  8. This above procedure to be adopted along the the direction of the traffic through the project end.

Precaution :

 Road should be barricaded by the safety cone

  1. Two flagmen should be deployed with red flag to direct the traffic


Methods Statement Ultrasonic Pulse Velocity Testing

Introduction : This test is done to assess the quality of concrete ,this method consists of measuring the time of travel of an ultrasonic pulse passing through the concrete being tested. Comparatively higher velocity is obtained when concrete quality is good in terms of density, uniformity, homogeneity etc. There are mainly two transmission methods ,  direct and indirect . In direct transmission method of ultrasonic pulse velocity is passes on opposite faces directly(both faces)  but in the indirect transmission method  transmission arrangement is placed on same faces .This is least sensitive and shall be used when only one face of the concrete is accessible, or when the quality of the surface concrete relative to the overall quality is of interest. If the transducers and receiver has been placed in same side it will be called Surface probing . Indirect velocity is invariably lower than the direct velocity on the same concrete element. This difference may vary from 5 to 20 percent depending largely on the quality of the concrete under test. For good quality concrete, a difference of about 0.5 km/s may generally be encountered. For the procedure and for calculating the exact value of ultrasonic pulse velocity by surface probing. it is recommended by the code IS 516 (Part 5/Sec 1) : 2018 while using  surface probing method the pulse velocity may be increased by 0.5

Reference code & Method : IS 516 (Part 5/Sec 1) : 2018 , Surface probing & Direct

Procedure :  We will use surface probing method due to one face accessible (Indirect Velocity).

1.At the point of observation, the concrete surface shall be suitably prepared and any plaster or other coating shall be removed to expose the concrete surface. For this purpose, the use of carborundum stones or grinders may be adopted. However, care shall be taken to avoid any damage to concrete surface or concrete structure.

  1. Before switching on the ‘V’ meter, the transducers should be connected to the sockets marked “TRAN” and ” REC”.
    The ‘V’ meter may be operated with either:
    a) the internal battery,
    b) an external battery or
    c) the A.C line.

3 . A reference bar is provided to check the instrument zero. The pulse time for the bar is engraved on it. Apply a smear of grease to the transducer faces before placing it on the opposite ends of the bar. Adjust the ‘SET REF’ control until the reference bar transit time is obtained on the instrument read-out.

  1. Place the two transducers on opposite faces (direct transmission), or on adjacent faces (semi-direct transmission), or on the same face (indirect or surface transmission) . For maximum accuracy, it is recommended that the 0.1 microsecond range be selected for path length upto 400mm

5.Having determined the most suitable test points on the material to be tested, make careful measurement of the path length ‘L’. Apply grease to the surfaces of the transducers and press it hard onto the surface of the material. Do not move the transducers while a reading is being taken, as this can generate noise signals and errors in measurements. Continue holding the transducers onto the surface of the material until a consistent reading appears on the display, which is the time in microsecond for the ultrasonic pulse to travel the distance ‘L’. The mean value of the display readings should be taken when the units digit hunts between two value. Calculate the pulse velocity by using following formula

Pulse velocity=(Path length/Travel time)

Reporting the Result : While reporting the result surface probing system should be considered.

Precaution : Prevent the two transducer leads from coming into close contact with each other when the transit time measurements are being taken. If this is not done, the receiver lead might pick-up unwanted signals from the transmitter lead and this would result in an incorrect display of the transit time.



Introduction:  Roughness is the distortion in the road profile, which is of main concern to the road users. It is caused due to the inherent properties of materials and the construction techniques. The pavement surface roughness is expressed as Unevenness or Roughness Index (in mm/ km) measured through Fifth Wheel Bump Integrator or Car Axle Mounted Bump Integrator. Bump Integrator also known as Roughometer or Automatic Road Unevenness Recorder gives quantitative integrate evaluation of surface irregularities on an digital counter / LCD screen. It comprises of a single wheeled trailer, with a pneumatic tyre mounted on a chassis, on which an integrating device is fitted . The operating speed of the machine should be 32±0.5 km/hr. The machine is towed by a vehicle, usually a jeep without disturbing the accuracy of the unevenness-measuring wheel.

Reference Code : RC:SP:16-2019

Procedure : Following procedure should be adopted while performing the test on finished road:

1.For bump integrator reading, first decide the stretch to be tested

2.Then at starting point i.e. at 0 distance, the BI reading is adjusted to “0” cm.

3.The instrument is driven over the stretch with a speed of  (32 +/- 2 km/h) on LHS and after crossing the end point marking; BI reading is taken and noted.

4.The result of bump integrator is generated in terms of count per km, which is the accumulation of the number of pulses in the total stretch.

5.Same test is repeated considering the speeds as mentioned above along in the stretches on RHS.

Recommended Standard Specification for Bituminous Concrete  

<1800 mm per Km





SCOPE: Compressive strength of concrete is very important criteria which can be easily computed by the Rebound Hammer .The rebound hammer is a nondestructive testing apparatus, whereby the rebound of the spring driven mass is measured after its impact with concrete surface. The output of the rebound hammer is referred to as rebound number and are correlated with surface hardness of concrete.

  1. RERFERENCE IS CODE: IS 516 (Part 5/Sec 4) : 2020

a. For testing, smooth, clean and dry surface is to be selected. If loosely adhering scale is present, this should be rubbed off with a grinding wheel or stone. Rough surfaces resulting from incomplete compaction, loss of grout, spalled or tooled surfaces do not give reliable results and should be avoided.

b. The point of impact should be at least 25 mm away from any edge or shape discontinuity.

c. For taking a measurement, the rebound hammer should be held at right angles to the surface of the concrete member. The test can thus be conducted horizontally on vertical surfaces (preferably) or vertically upwards or downwards on horizontal surfaces. If the situation demands, the rebound hammer can be held at intermediate angles also, but in each case, the rebound number will be different for the same concrete.

d. Around each point of observation, six readings of rebound indices are taken and average of these readings after deleting highest and minimum reading means we have to take 8 readings

e. After the average reading find out the corresponding Compressive strength from the graph .


Test result should record in in prescribed format

The report shall include the following:

a) Date/period of testing

b) Identification of the concrete structure/element

c) Identification of the rebound hammer;

d) Grade of Concrete

e) Test result and hammer orientation for each test area



  1. Purpose

Purpose of this test is too serve the behavior of the bridge by the application of design live load or load slightly exceeding design live load over a long period of 24 hours and elastic performance of bridge deck on removal of test load. It is used to assess the condition and safety of bridge. The load testing is used to check whether maximum deflection and percentage recovery are within permissible limits or not.

  1. Relevant code

Bridge Load Test shall be conducted as per guideline provided in IRC: SP: 51-2015.

3. Scope & Provided by Sponsor

Scope of work includes conducting the Span Load Test.

a) Span Length             –                        As per drawing

b) Test Span                 –                         As per drawing

c) Width of Carriage way –                As per drawing

d)Test Load                  –                         As per drawing

Method of Loading         –         By filling suitable material in truck.

e) Location of Dial Gauge At L/4, L/2 and 3L/4 of the bottom side of girder.

(where L is the c/c distance between the bearing) as indicated in or as specified in Drawing

f) Dial Gauge to be installed for Test Span– 3 nos. Dial Gauge on one girder as mentioned in drawing.

g) Nos. of Dial Gauge to be installed for Bearings settlement – 2 nos. or as mentioned in drawing.

4. Test Set-up for Span Load Test

a. Deck shall be cleaned properly; white wash shall be applied at the critical section on Girders. Deck shall be marked for the loading area as per drawing.

b. Trucks loaded with suitable material like aggregate, sand, cement bags etc.

c. Deflection of girder shall be measured by Dial Gauge of 0.1 mm least count which detect the Dial Gauge which are fixed on bottom side of girder.

d. Wherever Dial Gauge cannot be fixed on bottom side of girder due to water flow under bridge. Then total station and Dial Gauge should be used on top of deck slab of bridge. Point of Dial Gauge should be marked on top of deck slab at distance of L/4, L/2 and 3L/4 or distance given in drawing according to alignment of girder.


 1) The test will be carried out as per IRC SP 51 -2015 Instruments assembled at desired location such as, Dial Gauge, Strain Gauges & Digital Thermometer

 2) Visual inspection of bridge is done. In Visual Inspection, Bearing and expansion joints will be checked. Both must be in their functional and working condition. The traffic will be closed for further testing and whitewash is applied to the superstructure for monitoring of cracks.

3) Dial Gauges will be placed on magnetic stands. Dial Gauges will be placed firm on scaffolding platforms with steel plates, so that magnetic stands are firmly located. Dial gauges were mounted just by touching the soffit of structure.

 4) Glass plate of size 50x50x5 mm shall be fixed to structure at location of Dial Gauges for positioning.

 5) Before loading the precautions should be taken.

a) All staging provided shall be stable and safe.

b) Staging for instruments and observers shall be independent.

c) Staging for instruments shall be rigid.

6) As per IRC SP 51, Loading Operation Stages from 50%, 75%, 90%, 100% of test load in 4 stages, which shall be completed in 4 hrs. At the starting of Bridge load test 50 % of load on bridge is taken, out of total  50%  then 75%  then 90%  & 100% . We had to increment the load at the interval of every 1 hour during this the deflection will be recorded at each stage of loading.

7) After completing loading, we had to keep it retained for 24 hrs and observe.

8) After 24 hours, Structure shall be unloaded at same stage of loading i.e. 100% , 90% , 75% , 50% & 0%. But unloading shall be done in same way of loading , load shall be removed at 1 hour of interval from 100% to 90% to 75% to 50%  to 0%  as well as deflection is rewarded at each stage.

9) Measurements will be recorded at every hour of loading and unloading.

10) Data will be collected by visual observation before and after loading and there will be interpretation of results


The following observation shall be made before/during/after testing

i) Deflection at critical section

ii) Appearance of crack and their development, length and location

iii) Deformation of bearing

iv) Ambient temperature and relative temperature of the body in the structure

  1. Temperature Measurement

Temperature of any component like pier, abutment wall of the bridge will be monitored at every one hour or as per drawing. For structure temperature, drill a hole and put digital thermometer in hole at any one point. Also environmental temperature should be recorded.  The measurement will be taken by the digital thermometer. Reading of Dial Gauge point at every one hour or as per drawing should be note down for 24 hours. The reading of temperature will be used in temperature correction factor.