CEN/TC 51/WG 12 - Special performance criteria

This Technical Specification describes the testing of the freeze-thaw scaling resistance of concrete both with water and with sodium chloride solution. It can be used either to compare new constituents or new concrete compositions against a constituent or a concrete composition that is known to give adequate performance in the local environment or to assess the test results against some absolute numerical values based on local experiences.
Extrapolation of test results to assess different concretes, i.e. new constituents or new concrete compositions, requires an expert evaluation.
NOTE   In some cases the test methods may not be suitable for testing special concretes e.g. high strength concrete or permeable concrete. In these cases the result needs to be treated with caution. Also, the testing methods included in this document may not identify aggregates that are subject to occasional ‘pop-outs’.
There is no established correlation between the results obtained by the three test methods. All tests will clearly identify poor and good behaviour, but they differ in their assessment of marginal behaviour. The application of different acceptance limits for test results enables assessment for different degrees of exposure severity. Change of parameters of the testing procedure may have artefacts, some of which explained in Annex A.

1   Basic principle and key points of ICC
1.1   Basic Principle
The test method is designed to measure the heat of hydration of cement when mixed with water. The measurement takes place at essentially constant temperature, if the instrument and the measurement are well designed, therefore it is assumed to be the "isothermal heat of hydration of cement".
An isothermal heat conduction calorimeter (here called calorimeter) consists of a thermostatic heat sink upon which two heat flow sensors are placed. The sample is placed in an ampoule that is placed in an ampoule holder that is in contact with one of the heat flow sensors, and an inert reference is placed in contact with the other. The sample ampoule and the reference ampoule are thermally connected by heat flow sensors to a thermostatic heat sink. The output from the calorimeter is the difference between the outputs from the sample heat flow sensor and the reference heat flow sensor. A general scheme of a heat conduction calorimeter is given in Figure 1.
However the actual design of an individual instrument, whether commercial or home-built, may vary.
(...)
Most part of the calorimeters can measure the heat of hydration of samples mixed outside from the instrument therefore the heat produced during the mixing is not measured. It is not easy to solve this problem designing a calorimeter provided with an internally mixing device having the proper efficacy.
1.2   Key points of ICC
When performing ICC measurements on cement samples some key points have to be considered and correctly managed:
-   Constant value of the temperature of the thermostat;
-   Stability of the temperature of the thermostat all over the test duration;
-   Control of the maximum difference between sample temperature and thermostat temperature (isothermal conditions);
-   The baseline of the instrument (measured with an inert sample of similar thermal properties of test sample) should be both repeatable and stable;
-   Calibration of the calorimeter. The method currently used is based on the joule effect produced by a resistor feed with an electrical current; no standard material for the calibration is available for the time being;
-   Check that the ampoule is vapour tight enough (so that endothermic thermal powers of evaporation do not influence the measurements).

This Technical Report describes a method for characterising the time-dependent leaching behaviour of components from hardened concrete, for use in the natural environment.
This method specifies the procedures for determining the controlling mechanism(s) for leaching of components, their effective diffusion coefficients, in the case of diffusion-control and their cumulative release behaviour over any period of time.
This characterisation method consists of two leaching test procedures.  A potential or availability (pulverised specimen) test and a diffusion (tank) [monolithic specimen] test.
The test procedures produce leachates, the analytical procedures for which are not included in this Technical Report.
This Technical Report does not comprise a compliance method.
NOTE 1   The information obtained from the method is quantitative.  In the absence, however, of similar information for other construction materials or compliance criteria for acceptable/unacceptable performance of hardened concrete, the data obtained with neither permit a relative nor an absolute assessment of the environmental quality/compatibility of the concrete, unless, by default, in the case where leached concentrations of environmentally significant components are at, or below, their analytical limits of detection.
NOTE 2   In principle, this method could be used to characterise the leaching behaviour of hardened concrete, irrespective of the exposure conditions (e.g. natural environment, contact with drinking water etc.) which the concrete would experience in service.  It should be noted, however, that a European standard test method for the extraction/migration of mineral micropollutants is also likely to be developed by CEN/TC 164 - Water supply.
NOTE 3   Analytical procedures for determining concentrations of components in leachates and which may be suitable for the purposes of this Technical Report are being developed by CEN/TC 292 - (...)

This document outlines three test methods.  The first is designed to test the constituents of concrete, not designated as WT products, using reference concrete matrices (control mixes and test mixes) wherein the release of (regulated) dangerous substances from the constituent under test, into soil, groundwater or surface water, can be determined.  The types of constituent which can be tested using this method are as follows:
a)   factory-made cements;
b)   aggregates;
c)   additions type I;
d)   additions type II;
e)   admixtures;
f)   polymer modifiers;
g)   fibres.
The second method, in normative Annex A, is designed to test factory made concrete products, not designated as WT products, as either test pieces sawn or cored from pre-hardened monoliths or as standard-sized moulded test pieces formed from proxy samples of fresh wet material taken from concrete used in the production of factory made items.
The third method, in informative Annex B, is designed to test concretes sampled in the fresh wet state or pre-packaged state, not officially classified as WT products, as standard-sized moulded test pieces.
All three methods produce eluates that may be used for the purposes of characterisation testing, initial type testing (ITT) or further testing (FT) of either the constituents of concrete identified in this Scope or of production concretes.

Under the terms of EU Mandate 114, committee CEN/TC 51, cement, building limes and other hydraulic binders, is required to develop standards for ‘common cements’ and also for cements with special properties such as low heat cements, calcium aluminate cements and sulfate resisting cements.
EN 197-1: Composition, specifications and conformity criteria for common cements was adopted in 2000 and was the first harmonised European Standard to be adopted for a construction product.
Since 2000, European Standards for masonry, low heat, low early strength blastfurnace cements, very low heat special cements and calcium aluminate cements have been published.  The development of a prescriptive EN for sulfate resisting cements has been complicated by national differences in the types of cement that are recognised to have sulfate resisting properties.  Note, however, that all nationally standardised sulfate resisting cements meet the requirements of EN 197-1:2000, and that the absence of a specific standard for sulfate resisting cement has not constituted a barrier to trade.

This document specifies three test methods for the estimation of the freeze-thaw resistance of concrete with regard to internal structural damage. It can be used either to compare new constituents or new concrete compositions against a constituent or a concrete composition that is known to give adequate performance in the local environment or to assess the test results against some absolute numerical values based on local experiences.
Extrapolation of test results to assess different concrete i.e. new constituents or new concrete compositions requires an expert evaluation.
NOTE   Specification based on these test methods should take into account the behaviour of concrete under practical conditions.
There is no established correlation between the results obtained by the three test methods. All tests will clearly identify poor and good behaviour, but they differ in their assessment of marginal behaviour.

No scope available

This Technical Specification describes the testing of the freeze-thaw scaling resistance of concrete both with water and with sodium chloride solution. It can be used either to compare new constituents or new concrete compositions against a constituent or a concrete composition that is known to give adequate performance in the local environment or to assess the test results against some absolute numerical values based on local experiences.
Extrapolation of test results to assess different concretes i.e. new constituents or new concrete compositions, requires an expert evaluation.
NOTE   In some cases the test methods may not be suitable for testing special concretes e.g. high strength concrete or permeable concrete. In these cases the result is to be treated with caution. These tests may not identify aggregates that are subject to occasional ‘pop-outs’.
There is no established correlation between the results obtained by the three test methods. All tests will clearly identify poor and good behaviour, but they differ in their assessment of marginal behaviour
There are two types of concrete deterioration when a freeze-thaw attack occurs, scaling and internal structural damage. Test methods on internal structural damage are described in a CEN Technical Report CEN/TR 15177 "Testing the freeze-thaw resistance of concrete - Internal structural damage".

This European Standard describes a method of measuring the heat of hydration of cements by means of semi-adiabatic calorimetry, also known as the Langavant method. The aim of the test is the continuous measurement of the heat of hydration of cement during the first few days. The heat of hydration is expressed in joules per gram of cement.
This standard is applicable to all cements and hydraulic binders, whatever their chemical composition, with the exception of quick-setting cements.
NOTE 1   An alternative procedure, called the solution method, is described in EN 196-8. Either procedure can be used independently.
NOTE 2   It has been demonstrated that the best correlation between the two methods is obtained at 41 h for the semi-adiabatic method (EN 196-9) compared with 7 days for the heat of solution method (EN 196-8).

This European Standard describes a method of determining the heat of hydration of cements by means of solution calorimetry, also known as the solution method. The heat of hydration is expressed in joules per gram of cement.
This standard is applicable to cements and hydraulic binders whatever their chemical composition.
NOTE 1   Another procedure, called the semi-adiabatic method, is described in prEN 196-9. Either procedure can be used independently.
NOTE 2   It has been demonstrated that the best correlation between the two methods is obtained at 7 days for the solution method compared with 41 h for the semi-adiabatic method (prEN 196-9).