ДСТУ Б EN 12607-1:2015
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EN 12607-1:2014 - - - EN 58, EN 1425, EN 1426, EN 1427, EN 12594, EN 12596, EN 12735-1, EN 13302
BITUMEN AND BITUMINOUS BINDERS.DETERMINATION OF THE RESISTANCE TO HARDENING UNDER INFLUENCEOF HEAT AND AIR.
Part 1. RTFOT method
1 1 Scope
This part of EN 12607 specifies a method for measuring the combined effects of heat and air on a thin moving film of bitumen or bituminous binder simulating the hardening which most bituminous binder undergoe during mixing in an asphalt mixing plant.
The method described is not applicable to some modified binders or to those where the viscosity is too high to provide a moving film. In some cases the sample may creep out of the glass container and flow on the heating elements of the oven during testing. The method is suitable for other bituminous binders than paving grade bitumen, but the reference temperature might give excessive hardening that do not resemble real conditions during mixing at the plant. The method may not represent the hardening that occurs during mixing of warm mix binders.
The method is referred to as RTFOT, i.e. Rolling Thin Film Oven Test.
WARNING - Use of this European Standard can involve hazardous materials, operations and equipment. This European Standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this European Standard to identify the 2 EN 58. EN 1425. EN 1426. EN 1427. EN 12594. EN 12596. EN 12735-1. EN 13302. If there is a likelihood of volatile components being present in a binder, this procedure should not be used. It should not be used for cutback bitumen or bituminous emulsions before these products have been stabilised, e.g. in accordance with EN 13074-2.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 58, Bitumen and bituminous binders - Sampling bituminous binders
EN 1425, Bitumen and bituminous binders - Characterization of perceptible properties
EN 1426, Bitumen and bituminous binders - Determination of needle penetration
EN 1427, Bitumen and bituminous binders - Determination of the softening point - Ring and Ball method
EN 12594, Bitumen and bituminous binders - Preparation of test samples
EN 12596, Bitumen and bituminous binders - Determination of dynamic viscosity by vacuum capillary
EN 12735-1, Copper and copper alloys - Seamless, round copper tubes for air conditioning and refrigeration. Part 1: Tubes for piping systems
EN 13302, Bitumen and bituminous binders - Determination of dynamic viscosity of bituminous binder using a rotating spindle apparatus
3 4 4.1 - - - - - A moving film of bituminous binder is heated in an oven to a specified temperature for a given period of time with a constant supply of air.
The effects of heat and air are determined based on the change in mass (expressed as a percentage) or on the change in the bituminous binder's characteristics such as penetration according to EN 1426, softening point according to EN 1427 or dynamic viscosity according to EN 12596 or EN 13302, before and after the period in the oven.
The reference temperature of this conditioning is 163 4 Apparatus
Usual laboratory apparatus and glassware, together with the following:
4.1 Oven, rectangular, double-walled and electrically heated. The inside dimensions excluding the air plenum shall be as follows:
- height: (340 - width: (405 - depth: (445 The front door shall contain a symmetrically located window of the following dimensions:
- width: (320 - height: (215 This window shall contain two sheets of heat resistant glass separated by an air space. The window shall permit an unobstructed view of the interior of the oven.
The top of the upper heating element shall be (25 The oven shall be ventilated by convection currents of air; the oven shall have air inlets and outlets for the evacuation of hot gases. The air inlets toward the bottom of the oven shall be located so that the air is able to flow around the heating elements and their total open area shall be (1500
The oven shall incorporate an air flow around the side walls and ceiling. The air plenum (between the wall and the sheaths) shall be of uniform thickness (38 On the upper surface and at the midpoint of the width of the oven and (150 The fan shall be set so that it turns in an opposite direction to its vanes. The air flow characteristics shall be suction from the floor of the oven then flow along the walls in the sheaths fitted for this purpose and exhaust at the upper surface through the fan (Figures 1 a) and Figures 1b)).
The oven shall be equipped with a thermostat capable of maintaining a constant temperature to The temperature shall be recorded inside the oven with the reading point (25 4.2 4.3 - - The oven shall be equipped with an air jet positioned to blow heated air into each container at its lowest point of travel. The air jet shall have an outlet orifice with a diameter of (1,0 NOTE Activated silica gel treated with an indicator is a satisfactory desiccant for the air.
The performance of the equipment (particularly the motor rotation speed and the fan rotation speed) should be verified and action should be taken if it does not comply with the requirements stated in this method.
4.2 Flow meter, capable of measuring the airflow at a rate of (4,0 4.3 Temperature measuring device
A temperature measuring device (combining sensor and reading unit) shall:
- have a range from at least 150 - be readable to 0,1 - have an accuracy of 0,5 Sensors based on platinum resistance thermometers have been found suitable but other principles are also allowed. The thermal response time of the sensor shall be comparable with the former used reference (see informative Annex A). The temperature measuring device shall be calibrated regularly.
A solid stem mercury thermometer (which used to be the former reference thermometer as described in Annex A) is also allowed if national regulations permits its use.
4.4 4.5 When measuring and controlling nominally constant temperatures, as in this test method, the thermal response time can be rather high (e.g. slow response to a change in temperature). Care shall be taken to consider this aspect since low thermal response times of the sensor can indicate greater cyclic variations than the bituminous material in practice experiences.
4.4 Glass containers, (in which the sample of bituminous binder is subjected to the test), made of heatresistant glass conforming to the dimensions shown in Figure 3.
NOTE An outside opening (convex) is more suitable than the standard inside (concave) opening to facilitate the pouring of the hardened bituminous binder.
A special container with a removable groundglass stopper (which allows easier cleaning) can be used for non-referee purposes provided all the standardised dimensions are satisfied.
4.5 Balance, accurate to
1 - 2 - З? - 4 - 5 - 6 - Figure 1 - Oven and squirrel cage-type fan
1 - (3,0+0,1) 2 - З? - 4 - 5 - 6 - 7 - 8 - 9 - 10-4 11-8 Key:
1 (3,0 (300 2 spring clips glass container retainer
3 oven
4 sample glass container
5 thermometer
6 copper tubing; diameter: (8,0 7 orifice; diameter: (1,0 8 spacer length: (55 + 1,0) external diameter:
(12 9 spacer length: (20 10 4 M6 screws at 90 11 8 holes, diameter: (66,7 A-A
064 ext. 32
5.1 5.2 5.3 - - - - 5 Sampling
5.1 General
Make sure the laboratory sample is homogeneous and is not contaminated (see EN 1425). Take all necessary safety precautions and ensure that the test sample is representative of the laboratory sample from which it is taken (see EN 58). The laboratory sample shall be taken in accordance with EN 58.
5.2 Test sample preparation
Prepare the test sample in accordance with EN 12594. Remove a sufficient quantity of the laboratory sample to perform tests to establish the characteristics to be measured on the bituminous binder before and after the RTFOT hardening test. If necessary, use a warmed knife and transfer it to a suitable container according to EN 12594.
The sample shall be free of water. Heat the sample in an oven in its container with a loosely fitted cover, to a temperature not exceeding 10 5.3 Initial characteristics
Determine the initial characteristics of the bituminous binder e.g.:
- P v penetration at 25 - Tp ring and ball softening point (EN 1427);
- T]-], dynamic viscosity at 60 6 6.1 6.2 6 Procedure
6.1 Test conditions
Make sure the oven (4.1) is level so that the horizontal axes of the glass containers (4.4) when in position in the carriage, are level. Pre-heat the oven to the test temperature.
NOTE 1 The reference temperature of the test is (163 NOTE 2 Pre-heating the oven for 1 h is generally sufficient.
6.2 Determination and measurement
Weigh separately at least two identifiable empty glass containers (labelled A and NOTE 1 It may be advantageous to document the mass of all the glass containers to determine the change in mass even if the procedure described fails for the containers A and B. Check that the RTFOT oven can endure elevated temperatures before running the test.
Pour (35,0 To determine the percentage change in mass, take the two labelled containers (having empty masses and m When the oven has attained the set test temperature, arrange the containers holding the bituminous binder in the carriage so that the carriage is balanced. Fill any unused spaces in the carriage with empty containers. Close the door and rotate the carriage assembly at a rate of (15,0 6.3 NOTE 2 The aging time (75 Allow the two containers (A and B) to cool for about 1 h to ambient temperature in a desiccator. Weigh to within 1 mg to determine the relative masses, m” and m Discard the residue from