civil test report

1. REPORT ON NON-DISTRUCTIVE TEST FOR PHOENIX
MULTIPLEX THEATRE, G.T.ROAD, GUNTUR,
ANDHRA PRADESH.
CLIENT
M/s Phoenix Multiplex Pvt.Ltd, Guntur.
TESTING AGENCY
Nuthalapati Quality Control Lab,
Plot No. 386, Rajeev Township, Opp. Chalapati Engg. College,
Lam, Guntur-522034
REPORT ON NON-DESTRUCTIVE TEST
Project
Construction of proposed G+1 Individual House, Door No:
6 -187/2, Vasavinagar, Chilakaluripet, Guntur,
Andhrapradesh.
Job work : Rebound Hammer Test
Ultrasonic Pulse Velocity Test
Client : Mr. Shaik Jani Basha,
Door No: 6 -187/2, Vasavinagar,
Chilakaluripet, Guntur,
Andhrapradesh.
Investigation By
M/s Nuthalapati Quality Control Lab
Technical Report
----------------------------------------------------------------------
Prepared by:
Nuthalapati Quality Control Lab
Plot No-386, Rajeev Township,
Opp Chalapathi Engineering College,
Lam, Guntur - 522034
16/10
2021
Ph.No: 9441787343

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CONTENTS
1. INTRODUCTION 3
2. SCOPE OF WORK 3
3. REBOUND HAMMER TESTING 3
4. REBOUND HAMMER TEST RESULTS 4
5. ULTRASONIC PULSE VELOCITY TESTING 6
6. ULTRASONIC PULSE VELOCITY TEST RESULTS 8
7. CONCLUSION 10
8. PHOTOGRAPHS 11

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1.0 INTRODUCTION
Mr. Shaik Jani Basha, Door No: 6 -187/2, Vasavinagar, Chilakaluripet, Guntur,
Andhrapradesh for Construction of proposed G+1 Individual House, Door No: 6 -
187/2, Vasavinagar, Chilakaluripet, Guntur, Andhrapradesh approached M/s
Nuthalapati Quality Control Lab to carry out NDT Tests on RCC Framed
Structure like Rebound Hammer Test (RHT) and Ultrasonic Pulse Velocity Test
(UPV) at Guntur, Andhra Pradesh. Accordingly, NQCL took up the work as per
the following scope.
2.0 SCOPE OF WORK
i. Carry out Rebound Hammer Test and Ultrasonic Pulse Velocity Test
(RHT&UPV), of 3 RCC Framed Structure as per IS: 13311-1992 (Part-2) & IS
516 (Part 5/Sec 1): 2018 to ascertain the likely surface compressive strength
of Concrete & Quality of concrete in selected RCC Framed Structure
locations. The representative testing samples from different location shall be
selected by random sampling technique. The average of the readings
becomes the rebound index at that point of observation.
ii. Preparation of report covering above
3.0 Rebound Hammer Testing (RHT) As Per IS: 13311 (Part 2) – 1992
Rebound hammer testing technique was used for assessing the likely surface
compressive strength of concrete. Basic principle of rebound hammer test is given
below.
When the plunger of rebound hammer is pressed against the surface of the
concrete, the spring-controlled mass rebounds and the extent of such rebound
depends upon the surface hardness of concrete. The surface hardness and therefore
the rebound are taken to be related to the compressive strength of the concrete. The
rebound is read off along a graduated scale and is designated as the rebound

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number or rebound index. It is also to be noted that rebound indices are indicative
of compressive strength of concrete to a limited depth from the surface. If the
concrete in a particular member has internal micro cracking, flaws or heterogeneity
across the cross-section, rebound hammer indices will not indicate the same.
IS: 13311 (Part 2)-1992 states, “As such, the estimation of strength of concrete by rebound
hammer method cannot be held to be very accurate and probable accuracy of prediction of
concrete strength in a structure is ±25 percent.” However, the test should only be used
as indication of the probable compressive strength of concrete.
4.0 Rebound Hammer Test Results
Equipment details: Rebound Hammer
Equipment Make: Proceq
Calibration details: In house calibration as per the procedure given IS 13311(Part 2)
Rebound Hammer testing was carried out on various identified surface locations of
3 No’s of RCC Framed Structure using random sampling technique. The results of
surface compressive strength obtained by Rebound Hammer testing are given in
Table 1.

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Table 1
Surface Compressive strength results of concrete [As per IS: 13311 (Part 2) – 1992]
S.No
Structural
Element
Direction
Average
Rebound
Index
(N/mm
2
)
Corrected
Surface
Compr.
Strength
(N/mm2)
Remarks
29 34 27
28 33 35
34
24 21 31
23 26 22
25
30 32 31
29 20 25
Rebound Index
(N/mm
2
)
STRUCTURE: RCC FRAMED STRUCTURE
REBOUND HAMMER TEST TESTED AS PER IS:13311- Part 2
Date of Testing : 15-10-2021
Slab
C4
27.83 14.2
1 31.43 28.0 Column
24.57 16.7 Beam
3 S1
2 B2

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5.0 Ultrasonic Pulse Velocity (UPV) Measurement as per IS: 516 (Part 5/Sec 1)-2018:
Equipment details: Ultrasonic Pulse Velocity tester
Equipment Make: Proceq
Calibration details: In house calibration as per the procedure given IS: 516 (Part
5/Sec 1)-2018
UPV is a non-destructive evaluation method for assessing the quality of concrete
homogeneity; changes in the structure of the concrete which may occur with time;
presence of cracks, voids and other imperfections; quality of one element of
concrete in relation to another etc. Basic principle of UPV method is given below.
In this method, an ultrasonic pulse of longitudinal vibrations is produced by an
electro-acoustical transducer which is held in contact with one surface of the
concrete member under test. After traversing a known path length in the concrete,
the pulse of vibrations is converted into an electric signal by a second electro-
acoustical transducer, and an electric timing circuit enables the transit time of the
pulse to be measured, from which the pulse velocity is calculated. For the present
investigation, the pulse velocity measurements were obtained by direct
transmission of ultrasonic pulses through the concrete, i.e. by “cross probing”. For
this purpose, the transducers were held on opposite faces of the columns.
The Ultrasonic Pulse Velocity in concrete is mainly related to its density and
modulus of elasticity. This in turn depends upon the materials and mix proportions
used in making concrete as well as methods of placing, compaction and curing of
concrete. If the concrete is not thoroughly compacted, or if there is segregation of
concrete during placing or there are internal cracks or flaws, the pulse velocity will
be lower, although the same materials and mix proportions are used. The
underlying principle of assessing the quality of concrete from ultrasonic pulse
velocity method is that, comparatively higher pulse velocities are obtained when

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the ‘quality’ of concrete in terms of density, homogeneity and uniformity is good. In
case of concrete of poorer quality, lower velocities are obtained. On this basis,
Guidelines have been evolved for characterizing the quality of concrete in
structures in terms of ultrasonic pulse velocity. Such a guideline is given in Table 2,
which is reproduced from IS: 13311 (Part I) – 1992.
UPV conducted on Surface locations of 3 No’s of RCC Framed Structure. UPV
Calibration done at site using the calibrating prism provided by the manufacturer.
Results are presented in Table 3.
Table 2
Velocity Criteria for Concrete Quality Grading [As Per IS: 516 (Part 5/Sec 1) –
2018]
[By Cross Probing Method- Table 2]
Sl No.
Pulse Velocity by Cross-
Probing (km/sec)
Concrete Quality
Grading
1 Above 4.40 Excellent
2 3.75 to 4.40 Good
3 3.0 to 3.75 Doubtful
4 Below 3.0 Poor

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6.0 Ultrasonic Pulse Velocity (UPV) Test Results:
Table 3
Ultrasonic Pulse Velocity (UPV) Measurement as per IS: 13311 (Part 1)-1992:
DIRECT METHOD
SI No
Structural
Element
Path
Length
mm
Time Micro
Seconds
Velocity
Km/Sec
Average
Velocity
Km/Sec
Quality of
Concrete As
per Table IS
13311-Part1
Remarks
280 127.9 2.19
280 183.4 1.53
280 171.9 1.63
1
Column
C4
1.78 Poor Cross Probing
ULTRASONIC PULSE VELOCITY TESTED AS PER IS: 516 (Part 5/Sec 1) – 2018
Date of Testing : 15-10-2021
STRUCTURE: RCC FRAMED STRUCTURE

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INDIRECT METHOD
Note: Surface probing in general gives lower pulse velocity than in case of cross probing,
the difference could be of the order of about 0.5 km/set. (As per
IS 516 (P-5/ Sec 1) 2018-clause no.2.4.3.2.5)
SI No
Structural
Element
Path
Length
mm
Time Micro
Seconds
Velocity
Km/Sec
Average
Velocity
Km/Sec
Surface
probing
difference
@+0.5 km/set
Quality of
Concrete As
per Table IS
13311-Part1
Remarks
150 167.9 0.89
150 78.4 1.91
150 162.2 0.92
150 182.6 0.82
150 318.0 0.47
150 546.0 0.27
150 222.0 0.68
150 380.0 0.39
Poor
1.64
Surface
Probing
1
Beam
B1
1.14
ULTRASONIC PULSE VELOCITY
STRUCTURE: RCC FRAMED STRUCTURE
TESTED AS PER IS: 516 (Part 5/Sec 1) – 2018
Surface
Probing
0.95
2
Corner
Slab
(S1)
0.45
Date of Testing : 15-10-2021
Poor

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7.0 CONCLUSION:
As per the field observation and non-destructive tests, the following conclusions are
made.
For FRAMED SRUCTURE
1. Rebound Hammer Test conducted on Framed Structure at locations C4, B2
and S1 are varying from 14.2 N/mm2 to 28.0 N/mm2.
2. With the above results it is concluded that the average Quality of Concrete to
reinforcement of Framed Structure at locations C4, B2 and S1 are varying from
0.95 to 1.78 Km/sec. As per the Table -2, IS 516 (Part 5/ Sec 1): 2018, Concrete
quality grading is falling under “Poor”.
For Nuthalapati Quality Control Lab
Authorized Signatory

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8.0 Photographs: