poznan university of technology institute of building engineering division of building and building materials

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BUILDING MATERIALS – PRACTICAL SESSION

Lab 6

PROPERTIES OF BITUMEN AND BITUMINOUS MATERIALS

Flexible sheets for waterproofing: determination of mass per unit area and visible defects,

determination of tensile properties

European Standard

PN-EN 12311-1:2001 Flexible sheets for waterproofing. Part 1: Bitumen sheets for roof

waterproofing - Determination of tensile properties.

PN-EN 13416:2004 Flexible sheets for waterproofing. Bitumen, plastic and rubber sheets for roof

waterproofing. Rules for sampling.

PN-EN 1849-1:2002 Flexible sheets for waterproofing. Determination of thickness and mass per

unit area. Part 1: Bitumen sheets for roof waterproofing.

PN-EN 1850-1:2002 Flexible sheets for waterproofing. Determination of visible defects. Part 1:

Bitumen sheets for roof waterproofing.

Principle

For determination the tensile properties a test specimens are stretched at a constant rate of

extension until it ruptures. The tensile force and the corresponding change in length of the

specimen is continuously recorded throughout the test.

Apparatus

Measurement tools.

Cutting device.

Tensile testing machine equipped with a continuous recording of force and corresponding

distance.

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TEST PROCEDURE

Determination of mass per unit area

The test specimens shall be prepared from the test piece as present at the graph below. The

area of the test specimens are to be 100 cm2 ± 1%.

1 – width of the test piece, 2, 3, 4 – test specimens, 5 – edge strip

The test specimens are to be conditioned for at least 20 h at (23 ± 2) ⁰C and relative humidity in

the range 50 ± 5 % before testing. Weigh each of the test specimen rounded to the nearest 0,1 g.

The mass per unit area is given by the equation:

m =m1 + m2 + m3

3∙ 10−1 [kg/m2]

where:

m1, m2, m3 – mass of each tested specimens [g].

Determination of visible defects

The test piece are to be put on a flat surface and unroll. The top and the bottom surface of the

test piece is to be evaluate for a present of blisters, cracks, holes and no mineral granules.

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Determination of tensile properties

For a complete tensile test, two sets of test specimens are to be prepared: a set of five for the

longitudinal direction and a set of five for the transverse direction. Test specimens are to be cut at

random from a test piece not closer than 100 mm from the edge of the sheet, with the aid of

a template, or die cutter, to provide the rectangular test specimens measuring (50 ± 0,5) mm

wide by a length of at least (200 + 2x gripping length), the longer direction being the test

direction. The test specimens are to be conditioned for at least 20 h at (23 ± 2) ⁰C and relative

humidity in the range of 30 % to 70 % before testing.

The test specimen is to be tightly clamped in the tensile test machine grips taking care that the

longitudinal axis of the test specimen and the axis of the testing machine and grips are correctly

aligned. The clear distance between grips shall be (200 ± 2) mm. Mark the test specimens in

such a way that any slippage from the grips can be identified. A preload of maximum 5 N before

the start of the test is recommended to take out any slack in the test specimen. The test shall be

carried out at (23 ± 2) ⁰C with a constant speed of grip separation of (100 ± 10) mm per minute.

The tensile force and the corresponding distance of separation of the grips shall be recorded.

Determine the maximum force and the corresponding elongation calculated from the separation

of the tensile testing machine grips and expressed as a percentage of the original gauge length.

Disregard any test result where the test specimen breaks within 10 mm from the grips or when it

slips by more than the permitted limit within the grips of the tensile testing machine, and retest

with a replacement test specimen.

The maximum tensile force, expressed in N/50 mm, and corresponding elongation in percent are

noted, together with the direction of the test specimen. The mean values of tensile force shall be

rounded to the nearest 5 N and mean values of elongation shall be rounded to the nearest 1%.

poznan university of technology institute of building engineering division of building and building materials

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Bitumen and bituminous binders: determination of needle penetration and softening point

with ring and ball method

European Standard

PN-EN 12594:2014-12 Bitumen and bituminous binders. Preparation of test samples.

PN-EN 1427:2015-08 Bitumen and bituminous binders. Determination of the softening point. Ring

and Ball method.

PN-EN 1426:2015-08 Bitumen and bituminous binders. Determination of needle penetration.

Principle

The penetration is a consistency, expressed as the distance in tenths of a millimeter that

a standard needle will penetrate vertically into a sample of the material under specified conditions

of temperature, load and loading duration. The penetration of a standard needle into

a conditioned test sample shall be measured. For penetrations up to approximately (330 × 0,1)

mm the operating parameters shall be a test temperature of 25 °C, an applied load of 100 g, and

a loading duration of 5 s. For penetrations expected above approximately (330 × 0,1) mm, the

test temperature shall be reduced to 15 °C but the operating parameters of the applied load and

the loading duration remain unchanged. Other conditions can be applied; also to reflect different

purposes – e.g. 200 g, 60 s and 5 °C may be used as indicative for low temperature

performance.

Softening point is a temperature at which material under standardized test conditions attains

a specific consistency. The European Standard EN 1427 specifies a method for determination of

the softening point of bitumen and bituminous binders in the range of 28 °C to 150 °C. Two

horizontal discs of bituminous binder, cast in shouldered brass rings shall be heated at

a controlled rate in a liquid bath while each supports a steel ball. The softening point shall be

reported as the mean of the temperatures at which the two discs soften enough to allow each

ball, enveloped in bituminous binder, to fall a distance of (25,0 ± 0,4 mm).

Apparatus

Penetrometer with a penetration needle.

Ring and ball apparatus.

Test sample container – metal or glass, cylindrical, flat-bottomed. The internal depth of the

container shall be appropriate in order to contain a bituminous sample of which the depth shall be

at least 10 mm greater than the expected penetration, and not less than 35 mm and shall not

exceed 60 mm. The internal diameter of the container shall be at least 55 mm and shall not

exceed 70 mm. Recommended dimensions of the test sample container are given in Table 1.

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Table 1. Recommended dimensions of the test sample container

Penetration Internal depth Internal diameter Approx. volume of the sample

Approx. cooling time in air or conditioning time in

water

0,1 mm mm mm mL min

P < 160 35 55 80 60

160 ≤ P < 330 45 70 170 75

330 ≤ P ≤ 500 60 70 230 90

Water bath for needle penetration (the use of distilled or deionized water is recommended for the

bath).

Liquid bath for softening point – distilled or deionized water, glycerol.

Timing device capable of measuring the instant of release of the equipment and the duration of

the test to 0,1 s.

Temperature measuring device (combining sensor and reading unit) shall have a range from at

least 0 °C to 30 °C, be readable to 0,1 °C or less and have an accuracy of 0,1 °C or better.

TEST PROCEDURE

Needle penetration

Take the laboratory sample, taking all necessary safety precautions, and ensuring that the test

sample is representative of the laboratory sample from which it is taken. Ensure that the

laboratory sample is homogeneous and is not contaminated. Remove a sufficient amount of the

laboratory sample, if necessary using a warmed knife, and transfer it to a suitable container. Melt

the sample according to EN 12594. Raise the material to the required temperature of not more

than 100 °C above the expected softening point (see EN 1427) and fill one clean (free of dust,

grease, rust, etc...) test sample container. Fill the container with the homogenized sample to

a depth so that, when the test sample is cooled to the test temperature, the depth is 10 mm

greater than the depth to which the needle is expected to penetrate. For polymer modified

bitumen follow the procedure provided by the supplier. If no other guidance is provided by the

supplier for polymer modified bitumen according to EN 14023 the temperature shall be within

180°C to 200°C. The temperature shall not exceed 200 °C irrespective of the softening point.

Immediately after filling, loosely cover the test sample container with a container such as a lipped

beaker of suitable size. Allow the test sample to cool at an ambient temperature between 15 °C

and 30 °C:

for test samples < 45 mm depth − cool for 60 min to 90 min;

for test samples 45 – 60 mm depth − cool for 90 min to 120 min;

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for test samples with volume > 180 ml – cool for 60 - 90 min for each 100 ml of test

sample.

Place the test sample in the constant temperature bath for a similar period to that used for

cooling, and start testing. To avoid uneven surfaces of samples of hard bitumen according to EN

13305 after cooling, place the sample container filled with hot bitumen into the oven at

a temperature of approximate 80 °C for a period of 15 to 30 min. Then cool to ambient

temperature and continue as described in this standard. For measurement at temperatures lower

than 25 °C, longer cooling times can be required. When test conditions are not specified, for

penetration values below approximately (330 × 0,1) mm, the temperature, total applied load and

loading duration shall be 25 °C, 100 g and 5 s. For penetration values above approximately

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©M. Ratajczak

(330×0,1) mm, the test shall be carried out at conditions of 15 °C, 100 g and 5 s. When other

conditions are used, the details shall be reported in full.

With the test sample container in position, slowly lower the needle until its tip just makes contact

with its image reflected by the surface of the test sample. Ensure that the zero position of the

needle is noted, then, quickly release the needle holder for the specified period of time. If the

container moves during the determination, discontinue the test. Adjust the instrument as

necessary to determine the penetration of the needle into the sample in tenths of a millimeter.

The positioning of the needle can be aided materially by good illumination with a cold light

source. Carry out at least three valid determinations with three separate needles at points on the

surface of the test sample that are not less than 10 mm from the sides of the container and are

not less than 10 mm apart. Use a clean needle for each determination. If the penetration is

greater than (100 × 0,1) mm, leave all the needles in the test sample until all the determinations

have been completed. If necessary move the first two needles without disturbing the surface. If

the test is carried out outside the bath and the three determinations are not carried out according

to the temperature tolerance, return the test sample and transfer dish to the bath and repeat the

determination(s). For tests carried out under the conditions of a test temperature of 25 °C, a total

applied load of 100 g and a loading duration of 5 s, the three determinations shall be acceptable

if the range of the results obtained does not exceed the relevant value given in Table 2.

Table 2. Maximum range of the valid determinations

Penetration in 0,1 mm up to 49 50 to 149 150 to 249 250 and above

Maximum difference between highest and lowest determinations

2 4 6 8

These ranges are not necessarily applicable at other conditions. If the appropriate maximum

difference is exceeded, discard the results and repeat the test on a second sample test container.

If the appropriate range is again exceeded, ignore all determinations and repeat the test until

three valid determinations have been obtained on the same test sample. After completing the

test, clean the penetration needles with a suitable solvent and store so as to prevent corrosion or

damage. Do not use detergent or silicone oil for cleaning the needles. Express the penetration

value as the arithmetic mean of the acceptable determinations, in tenths of a millimeter rounded

to the nearest integer.

Softening point

Take the laboratory sample taking all the necessary safety precautions and ensuring that the test

sample is representative of the laboratory sample from which is taken. For modified bitumen the

quantity of sample shall be adjusted to fill four rings in case the test has to be repeated. Heat the

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two brass rings to a temperature of not more than 100 °C above the expected softening point and

place them on the pouring plate treated with the release agent. Pour a slight excess of the heated

bituminous binder into each of the rings, then allow the specimens to cool in ambient air for at

least 30 min. For materials that are soft at room temperature, cool the test sample for at least 30

min at an air temperature at least 10 °C below the expected softening point. No more than 4 h

shall elapse until completion of the test from the time the test are poured. When the test samples

have cooled, cleanly cut away the excess binder with a warmed knife or blade, so that each test

sample is flush and level with the top of its ring. Cut the excess of binder immediately before

placing the rings in the assembly.

Select the appropriate bath liquid as follows:

Softening points between 28 °C and 80 °C: use freshly boiled, cooled, distilled or deionized

water; the initial bath temperature shall be (5 ± 1) °C.

Softening points above 80 °C and up to 150 °C: use glycerol; the initial bath temperature shall be

(30 ± 1) °C.

Assemble the apparatus with the test sample rings, ball centering guides and temperature sensor

in position and fill the bath so that the surface of the bath liquid is (50 ± 3) mm above the upper

edge of the rings. Using forceps, place the two steel balls in the bath or in a separate container at

5 °C or 30 °C, as appropriate. Ensure that the balls have the same temperature as the rest of the

assembly. Place the bath in ice water or a thermostatic apparatus (device) to cool to (5 ± 1) °C

(where water is the bath liquid), or gently heat to (30 ± 1) °C (where glycerol is the bath liquid) to

establish the correct initial bath temperature. Maintain the assembly at the temperature for at

least 15 min but not more than 20 min. Take the bath containing the assembled apparatus out of

the ice water or thermostatic device, dry the outer surface gently to remove any liquid and place it

into the testing apparatus as quickly as possible. Using forceps, place a ball in each ball

centering guide. When water is used as bath liquid the first three minutes are for settling the

heating rate of 5 °C/min only. When glycerol is used as bath liquid the temperature range from 30

°C to 60 °C is intended for settling the heating rate of 5 °C/min and the temperature should have

reached (60 ± 1) °C after 6 min. After the first 3 min (water) or when 60 °C is reached (glycerol),

the temperature rise shall be between 4,4 °C and 5,6 °C in every individual minute measured.

poznan university of technology institute of building engineering division of building and building materials

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For each ring and ball, record the temperature indicated by the temperature device, the instant

the binder surrounding the ball touches the bottom plate. If the difference between the two

temperatures exceeds 1 °C for softening points below 80 °C or exceeds 2 °C for softening points

above 80 °C, repeat the test. For modified bitumen repeat the test if difference between the two

temperatures exceeds 2 °C or ball breaks the surrounding film before touching the bottom plate

or if partial detachment of binder from the ball is observed. The softening point of given bitumen

determined in a water bath is approximately 4 °C lower than the softening point of the same

bitumen determined in a glycerol bath. When softening point determined in water is above 80 °C,

reject the result as invalid and repeat the test in a glycerol bath. When softening point determined

in glycerol is below 84 °C, repeat the test in a water bath. If the test results determined in water

bath is 80 °C or lower, report this test result, otherwise report the result obtained in the glycerol

bath.

Express the test results to the nearest 0,2 °C for softening point below or equal to 80 °C and to

the nearest 0,5 °C for softening point above 80 °C. The mean values of determinations are

arithmetic means rounded up to the nearest 0,2 °C or 0,5 °C.