There is a growing need for health assessment and risk evaluation of existing structures and that in-situ quality meets the design requirements in under construction structures. Avantech Engineering Consortium offers a wide range of test services meeting Indian and/ or international standards and codes tests to assess the RCC structures for in-situ strength, integrity and corrosion analysis for reinforcement bars.

 

In-Situ Compressive Strength (design strength, and existing structures)

 

Cut And Pull Out Test (CAPO Test) Cut And Pull Out Test (CAPO Test)

Cut and Pull Out (CAPO) is a reliable test method to determine the in-situ compressive strength of RCC structures. The CAPO test results are found to be within 8% of the results obtained from conventional methods.

CAPO test is carried out in accordance with the guidelines laid out in ASTM C900, BS-1881: Part 207 and EN-12504-3.

Avantech Engineering has considerable experience of conducting the CAPO tests on various infrastructure projects for health monitoring of bridges, buildings etc. to estimate the in-situ strength of concrete.

Rebound Hammer Test Rebound Hammer Test

Rebound Hammer test measures the surface hardness of concrete with approximate correlations to estimate the compressive strength of the structure. Although the intrinsic limitations of the test may result in large variations in the estimated strength, ease of conducting the test and low initial cost has made the test quite popular.

Rebound Hammer tests are conducted in accordance with IS: 13311 Part II standard.

Avantech Engineering Consortium has been undertaking health monitoring projects for power plants, real-estate developers, construction agencies etc. and carrying out Rebound Hammer Tests as per the project requirements.

Core Tests Core Tests

Core tests involve taking the actual core samples from the structure using the diamond core cutting bits and subjecting the cores to compressive loading in the Compression Testing Machines, followed by the visual inspection.

Core tests are conducted in conformance with the guidelines laid out in IS: 456.

Avantech Engineering has been undertaking testing of cores as a part of health assessment of existing buildings.

 

 

Early Age Strength Estimation

A reliable knowledge of Early Age Strength Development in Concrete can help in reducing the project duration, and the project cost by early and more efficient mobilization of construction resources like shuttering etc.

LOK Test LOK Test

LOK test is a variant of a Pull Out tests to determine the early age strength gain in RCC structures. Specially designed metal inserts are attached to the shuttering/ structure and pulled out at a desired time to determine the current strength gain.

LOK test is carried out in accordance with the guidelines laid out in ASTM C900, BS-1881: Part 207 and EN-12504-3.

Maturity Method

Maturity Methods are based on the principal that the rate of hydration of cement is indicative of the early age strength development in concrete. Actual temperature history of the concrete is recorded by embedded probes, which is converted to estimate the current in-situ strength using the well established Maturity Functions.

The maturity method is governed by ASTM C1074.

 

Tests to Assess Integrity of RCC Structures

Integrity Assessment of RCC structures refers to the homogeneity of the structure and to examine the structure for any internal defects.

Ultrasonic Pulse Velocity Test (UPV) Ultrasonic Pulse Velocity Test (UPV)

Ultrasonic Pulse Velocity (UPV) Test involves the transmission of ultrasonic pulses through the structural member and computing the wave velocity in it. Thus computed velocity is an indicative of the quality of concrete and if the member is suffering from any structural flaw like honey-combing, voids etc.

UPV tests are conducted according to IS: 13311- Part 1.

We have a wealth of experience of conducting the UPV test as a part of health assessment projects for power plants, fertilizer complexes and infrastructure projects to meet the project requirements.

Impulse Response Test Impulse Response Test

Impulse Response Test uses a low-strain impact to cause the structural member to vibrate in a bending mode and compute the amplitude of the response through the probe placed on the surface.

The test system allows quick screening of structure for flaws like honeycombing, delaminations, voids etc. and identifies suspect areas for subsequent detailed assessment.

The Impulse Response Test conforms to ASTM C1740-10 standard. Avantech Engineering Consortium has carried out Impulse Response Test for screening of structural flaws in slabs in ware houses, deck slabs in buildings and bridges, airport aprons etc.

Impact Echo

Impulse Echo tests involve introduction of a stress pulse by a mechanical impact and studying the frequency response of the reflected waves. The dominant frequency in the frequency response is used to compute either the depth of the member or the possible depth of the flaw.

Measurement of Thickness of Concrete Members is governed by ASTM C1393- 98a standard.

Avantech Engineering Consortium has carried out Impact Echo tests to assess thickness of tunnel walls, crack depths and voids in tendons ducts in bridge girders.

Ground Penetrating Radar (GPR) Ground Penetrating Radar (GPR)

Ultra-high Frequency Ground Penetrating Radars (GPRs) have the ability to penetrate the RCC and provide the user with critical information on the condition and thickness of the structure. GPR allows the user to detect the structure for flaws like delaminations, voids, deterioration in the structure etc.

Avantech Engineering offers world class GPR services for a wide range of applications with state of the art equipment and professionally trained engineers. We have completed several projects in India involving the use of GPR for assessment of RCC structures for their integrity.

Crack Depth MeasurementCrack Depth Measurement

The Crack Depth is calculated by using the principle of acoustic diffraction of ultrasound waves. The method uses a specially designed test instrument where the transducers are positioned on the surface in a line across the crack. The average depth of crack is calculated by measuring the transit time at different distances of transducers from the crack, viz at 100mm, 150mm and 20mm.

Crack Depth MeasurementCrack Depth Measurement

 

Reinforcement Location and Corrosion Assessment

 

Reinforcement Location by Ground Penetrating Radar (GPR)

Ultra high frequency radars are an ideal system for locating and inspecting the reinforcement without damaging the existing structure. The system is a quick test method to examine the spacing, initiation of spalling and cover for the desired structural member. The test is the best solution to gather information for the multi-layer reinforcements.

Cover Assessment Cover Assessment

Concrete cover provides the protection to the Reinforcement bars against corrosion. It thus becomes essential that there should always be a cover of suitable depth existing between the surface and first layer of reinforcement. Cover meter detects the cover depth using the pulse induction technique.

Cover meter can also be used to estimate the depth, size and spacing between the reinforcement bars.

Avantech Engineering Consortium has carried out tests to estimate the cover depth for various RCC structures as a part of health assessment for power and infrastructure projects.

Cover Assessment Half Cell

Half Cell Potential Tests is used to estimate the likelihood of corrosion in the reinforcement bars. The test is used extensively for condition surveys of suspect RCC structures to identify areas with corrosion activity for further analysis to establish the cause of corrosion and estimate residual service life.

The test system conforms to ASTM C876.

Resistivity Tests

Resistivity Tests are carried out to determine the resistance of structural concrete to the active corrosion. When the resistivity of the concrete is high, it is assumed that the probability of active and rapidly advancing corrosion is low and vice versa.

Resistivity Test is a rapid test to ascertain the quality of concrete against rebar corrosion.

Corrosion Rate Assessment

Monitoring the corrosion activity and determining the rate of corrosion in the RCC structures is essential for the condition monitoring and estimating the service life of the structural member.

Corrosion Rate is measured using GalvaPulse. GalvaPulse evaluates the corrosion rate of reinforcement by measuring Galvanic resistance using the Galvanostatic pulse technique.

Carbonation Test Carbonation Test

The natural alkalinity in concrete provides a protective layer against corrosion. Carbon dioxide in air reacts with the Calcium salts, resulting in reduced pH, making the structure susceptible to corrosion. This reaction is termed as Carbonation.

The depth of carbonation is determined using Phenolphthalein as an indicator.

The test is a quick method to evaluate the cause of corrosion during corrosion surveys.

 

Repair Quality Assessment

 

Bond Test Bond Test

Bond test is a pull off test which is used to evaluate the in-place bond strength between a repair overlay and substrate, tensile strength of concrete/ other material, strength of surface concrete etc.

Anchor / Rebar Pull-out Strength  

Anchor / Rebar Pull-out Strength

Anchor/ Rebar Pull-out test is used for proof load testing of anchors in concrete.

A pull-out force is applied to the anchor using a specially designed adaptor and a counter pressure assembly. Design Load is applied to the anchor using a hydraulic pull machine and the pull-out strength of the anchor is determined.

 

 

 

Chemical Tests

Chemicals such as Chlorides, Sulphates, Ammonia etc. play a crucial role resulting in the corrosion of the reinforcement bars. Analysis of the structure for these chemicals can provide a key information regarding the extent of corrosion and estimation of the structural life of the member.