Water penetration test - Permeability test

Goal(s)

Main objective

The main objective of the water penetration test in bridges or tunnels diagnostics is the determination of resistance or durability of concrete extracted from elements of structure exposed to the water flow. The water permeability tests are the best for evaluating concrete durability under hydrostatic pressure and as a good indicator of its quality. The application in durability assessment of concrete elements of the existing structures is growing. The permeability test should be considered as an essential one to evaluate the case whereby concrete is subjected to hydrostatic pressure.

Description

Functioning mode

Pressurized water acts on the surface of the hardened concrete at a constant pressure of 500 (± 50) KPa, usually for a period of 72 hours. After the test, the sample should be immediately split in the plane of water penetration and the contour of the wetted area should be marked. The apparatus consists of a robust steel frame with clamping system, incorporating the hydraulic circuit, valves, gauge to check the water pressure and measuring transparent burettes mounted on top of the apparatus. The clamping system is adjusted for cube or prismatic specimens up to 200 mm side and cylinders up to 300 mm height.

After the pressure has been applied, the specimen should be split in half, perpendicularly to the face on which the water pressure was applied. When splitting the specimen, and during the examination, the face of specimen exposed to the water pressure should be placed on the bottom. As soon as the split face has dried to such an extent that the water penetration front can be clearly seen, the water front on the specimen can be marked .

WaterPenTest01.png
Fig 1 Pressured permeability tester

Types

Water penetration test can be distinguished into two types:

  • performed on the samples in laboratory – in a test chamber with water pipe ensuring continuous flow and homogeneous water coverage and air pressure applied,
  • performed on the built walls in the construction site conditions – in a test chamber with a box format and internal dimensions 160 mm x 340 m and no air pressure is used.

Process/event to be detected or monitored

Depth of the penetration of water after observation of the fracture structure after splitting the sample. The wet area is darker.

Physical quantity to be measured (e.g. actions, displacements, deformations, dynamic structural properties, material properties including mechanical, electrical and chemical properties, relative displacements of the two sides of a crack, etc.).

Measurement of the maximum range of water penetration from the surface. Maximum average depth for examined samples.

Induced damage to the structure during the measurement

For diagnostics of existing civil engineering structures it is necessary to collect samples from the structure in a borehole form, therefore the method is destructive.

General characteristics

Measurement type (static or dynamic, local or global, short-term or continuous, etc.)

Uncomplicated method of determination of the resistance to water penetration suitable for concrete structures such as bridges and tunnels and in general concrete elements. Measurement is static, local and short term – up to 72 hours.

Measurement range

Not applicable.

Measurement accuracy

Penetration from the surface should be measured with 1 mm accuracy .

Background (evolution through the years)

Historically tests on water penetration have been performed on windows by exposing them to rain and additional pressure.

The ASTM E1105 (Standard Test Method for Field Determination of Water Penetration of Installed Exterior Windows, Skylights, Doors, and Curtain Walls, by Uniform or Cyclic Static Air Pressure Difference) test procedure was specifically written for field testing and as a component to the quality assurance and commissioning process of a building enclosure. ASTM E1105 uses a calibrated spray rack to simulate rain from the outside and a negative pressure chamber inside to simulate wind. The procedure describes how to test with either a constant or a fluctuating interior pressure.

Another standard – ASTM E331 has been established in 1967. Further development consisted of transition from manual to automatic methods of testing. ASTM E514 M-20 Standard Test Method for Water Penetration and Leakage Through Masonry subjected to wind-driven rain. Has been introduced in 1990. US Army published in 1992 a procedure for determining the permeability of concrete subjected to water pressure (1,38 MPa) with a code - COE CRD-C 48-92 as a Handbook for Concrete and Cement Standard Test Method for water permeability of Concrete..

The ASTM C1601-10 Standard Test Method for Field Determination of Water Penetration of Masonry Wall Surfaces has been introduced in 2010 to determine criteria for water penetration resistance of masonry wall.

Performance

General points of attention and requirements

Design criteria and requirements for the design of the survey

Water pressure must not be exerted on the obliterated, smoothed surface of the extracted concrete sample. When fresh concrete sample is tested it is recommended that the pressure should be applied on the surface, which was in contact with the form.
For the samples extracted from the existing structures the area of ​​the sample to be subjected to water pressure must be cleaned with a steel brush. The depth of water penetration inside the sample decreases with the age of the samples .

Procedures for defining layout of the survey

No specific guidelines.

Design constraints (e.g. related to the measurement principles of the monitoring technologies)

In order to extract samples there should be safe access to the part of the existing concrete structure to avoid any risk. The sample at the time of testing must be at least 28 days old in case if fresh concrete is being examined.

Sensibility of measurements to environmental conditions.

When the surface of the material is obscured due to atmospheric soiling or biological growth and presence of hygroscopic salts within the interior the permeability of concrete will be affected. Formation of a weathering crust from mineralogical changes on the exposed surface will affect water permeability measurements.

Preparation

Procedures for calibration, initialisation, and post-installation verification

Cubic, cylindrical and rectangular samples can be used for the tests, provided that the minimum size of the area over which the water pressure is applied is not less than 150 mm. The diameter of the pressurized area is 75 mm. The water pressure can be exerted from above or below. Samples in the process of testing have to remain without any outer coating and the test itself is to be conducted in laboratorial conditions at a temperature of 20 ± 2oC and air humidity greater than 50%.

Procedures for estimating the component of measurement uncertainty resulting from calibration of the data acquisition system (calibration uncertainty)

Not applicable.

Requirements for data acquisition depending on measured physical quantity (e.g. based on the variation rate)

Not applicable.

Performance

Requirements and recommendations for maintenance during operation (in case of continuous maintenance)

Not applicable.

Criteria for the successive surveying campaigns for updating the sensors. The campaigns include: (i) Georeferenced frame, i.e. the global location on the bridge; (ii) Alignment of sensor data, relative alignment of the data collected in a surveying; (iii) Multi-temporal registration to previous campaigns; and (iv) Diagnostics.

Not applicable.

Reporting

An identification of sample should be included in the report, the direction of the supply of water in relation to the formation of the sample (perpendicular or in parallel), date, maximal penetration depth in mm, leak outline/cross section.

Lifespan of the technology and required maintenance (if applied for continuous monitoring)

Water penetration test is not used in continuous monitoring.

Interpretation and validation of results

Expected output (Format, e.g. numbers in a .txt file)

Cross-section of the drenched area of the split sample; the maximum depth of penetration, expressed in mm after different days period.

Interpretation (e.g. each number of the file symbolizes the acceleration of a degree of freedom in the bridge)

Cross section shows the image of dampness for different samples, which can be compared for different concrete classes. Values present the maximum depth of water penetration in concrete samples.

If the water penetration depth is below 50 mm concrete is classified as impermeable and if below 30 mm as impermeable in corrosion conditions .

Validation

Specific methods used for validation of results depending on the technique

The water penetration test can be coupled with observation on Scanning Electron Microscope to observe how the penetrated water behave inside the sample.

Quantification of the error

The test should be carried out on at least 3 samples to identify and reject any outliers (testing in accordance with the standard on a single sample does not provide such opportunities and may lead to a possible disqualification of a concrete batch that meets the requirements).

Quantitative or qualitative evaluation

Both quantitative and qualitative evaluation.

Detection accuracy

The water penetration depth should be detected with accuracy to 1 mm.

Advantages

Method can be performed with use of apparatus for testing water permeability with automatic control, which allows testing several samples simultaneously. Possibility of automatic testing in different research cycles as well as pressure reading directly from the pressure gauge, automatic water supply simplifies the procedures.

Disadvantages

Guidelines for performance of test do not specify precise age of the sample at which the test should begin, nor the cut-off age of concrete that can be tested. This fact indicates on the possibility of different result for this property.

Possibility of automatising the measurements

On the market there are available fully automatic apparatuses for cubic concrete specimens, where the water permeated through the test specimen is directly collected and measured. Each sample cell includes pressure control manometer, and the apparatuses are supplied with an automatic pump.

Barriers

No specific barriers to be included.

Existing standards

  • EN 12390-8:2019, Testing hardened concrete - Part 8: Depth of penetration of water under pressure
  • PN-EN 206+A2:2021-08, Concrete – requirements, properties, production and compliance
  • 1.11.3 ASTM C1601 – 11 Standard Test Method for Field Determination of Water Penetration of Masonry Wall Surfaces
  • DIN 1048 - Testing concrete; testing of hardened concrete (specimens prepared in mould)
  • DIN 1045-2 - Concrete, reinforced and prestressed concrete structures - Part 2: Concrete - Specification, performance, production and conformity - Application rules for DIN EN 2061.

Applicability

Relevant knowledge fields

Industry:

  • control of blasting process,
  • quality control in production of anti-corrosion coatings,


Civil Engineering:

  • water penetration of masonry wall surfaces.

Performance Indicators

  • holes
  • loss of section
  • rupture
  • deformation
  • displacement
  • cracks
  • wire break
  • tensioning force deficiency.

Type of structure

  • bridges
  • curtain walls
  • tunnels.

Spatial scales addressed (whole structure vs specific asset elements)

Water penetration test can be useful when used for the samples collected from the places particularly vulnerable to corrosion and chemical attack.

Materials

  • concrete
  • reinforced concrete
  • polymers
  • composites
  • wood

Available knowledge

Reference projects

Not reference projects

Other

CONTROL Groups


MATEST Automatic Concrete Permeability Apparatus

Bibliography

[1] A. M. Neville, T. R. (2012). Properties of Concrete. Pearson..
[2] ACI 201.2R-1992. (1994). Guide to durable concrete, ACI Manual of Concrete Practice Part 1: Materials and General Properties of Concrete. Detroit, Michigan..
[3] G. J. R. Von der Meulen, J. v. (1969). A Permeability - Testing Apparatus for Concrete. Journal of the PCA Research and Development Laboratories , 121-123..
[4] Gwizdak, M. (2015). Badanie wodoszczelności betonu – porównanie metod badawczych. Praca dyplomowa inżynierska. Poliecthnika Rzeszowska..
[5] I. L. Tyler, B. E. (1961). A Proposed Simple Test Method for Determining the Permeability of Concrete. Journal of the PCA Research and Development Laboratories, 2-7..
[6] PN-EN 12390-8:2019-08 . (2019, 08 02). Concrete tests - Part 8: Penetration depth of water under pressure..
[7] PN-EN 206+A2:2021-08 . (2021, 08 16). Concrete - Requirements, properties, production and compliance..
[8] Ritchie, T. (1974). Water Penetration Tests of Hollow Brick Walls..
[9] Young, J. F. (1988). ACI SP-108: A review of pore structure of cement paste and concrete and its influence on permeability . Detroit, Michigan ..
[0] Z. Kledyński, E. K. (2005). Ocena wodoszczelności betonu studium porównawcze norm polskich i europejskich. Wpływ warunków przygotowania próbek na ocenę wodoszczelności betonu. Cement Wapno Beton 4, 215-227..