This standard specifies the principle, instrument and equipment, test conditions and materials, test methods, results and calculations for the determination of the fluidity of cement mortar. This standard is applicable to the determination of the fluidity of cement mortar. GB/T 2419-2005 Method for determination of the fluidity of cement mortar GB/T2419-2005 Standard download decompression password: www.bzxz.net

ICS 91. 100. 10
National Standard of the People's Republic of China
GB/T 2419—2005
Replaces GB/T 2419—94
Test method for fluidity of cement mortarIssued on 2005-01-19
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of ChinaAdministration of Standardization of the People's Republic of China
Implementation on 2005-08-01
GB/T 2419—2005
This standard is revised with reference to the requirements of 5.5.2.1.2 fluidity jump table in EN 459-2:2001 "Building Lime". This standard replaces GB/T2419-1994 "Method for Determination of Fluidity of Cement Mortar". Compared with GB/T2419-1994, the main changes are as follows:
The cement mortar fluidity jump table with the same technical parameters as EN459-2:2001 is adopted, but the number of jumps is 25 times (Appendix A of the 1994 edition; Appendix A of this edition);
The composition of the mortar used for the fluidity test of cement mortar is determined according to the requirements of the corresponding standards or test design (Chapter 4 of the 1994 edition; Chapter 5 of this edition).
Appendix A of this standard is a normative appendix.
This standard is proposed by the China Building Materials Industry Association. This standard is under the jurisdiction of the National Cement Standardization Technical Committee (SAC/TC184). The responsible drafting unit of this standard is China Building Materials Science Research Institute. The participating drafting units of this standard are Wuxi Jianyi Instrument Machinery Co., Ltd., Beijing Cement Quality Supervision and Inspection Station, and Yunnan Building Materials Product Quality Supervision and Inspection Station.
The main drafters of this standard are: Liu Chen, Yan Bilan, Jiang Lizhen, Xiao Zhongming, Bai Xianming, Zhang Datong, Song Lichun, Bao Yuxi. The previous versions of the standards replaced by this standard are: GB2419--1981, GB/T 2419-—1994. 1
1 Scope
Method for determination of fluidity of cement mortar
GB/T2419-2005
This standard specifies the principle, instruments and equipment, test conditions and materials, test methods, results and calculations of the method for determination of fluidity of cement mortar.
This standard is applicable to the determination of fluidity of cement mortar. 2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, the latest version applies to this standard. GB/T17671--1999 Cement mortar strength test method (ISO method) (idtISO679:1989) JC/T681 Planetary cement mortar mixer
JBWO1-1-1 Cement mortar fluidity standard sample 3 Method principle
Measure the fluidity of a certain proportion of cement mortar under a specified vibration state by measuring the expansion range. 4 Instruments and equipment
4.1 Technical requirements for cement mortar fluidity tester (referred to as jumping table) and its installation method are shown in Appendix A. 4.2 Cement mortar mixer
Meet the requirements of JC/T681.
4.3 Test mold
It consists of a truncated cone round mold and a mold sleeve. It is made of metal material, and the inner surface is processed smoothly. The size of the round mold is; height 60mm±0.5mm;
inner diameter of the upper opening 70 mm±0.5mm;
inner diameter of the lower opening 100 mm±0.5 mm;
outer diameter of the lower opening 120mm;
mold wall thickness is greater than 5mm.
4.4 Tamping rod
Made of metal material, with a diameter of 20mm±0.5mm and a length of about 200mm. The bottom surface of the tamping rod is at right angles to the side surface, its lower part is smooth, and the upper handle is knurled. 4.5 Caliper
The measuring range is not less than 300mm, and the graduation value is not greater than 0.5mm. 4.6 Knife
The blade is straight and the length is greater than 80 mm.
4.7 Balance
The measuring range shall not be less than 1000g, and the graduation value shall not be greater than 1g. GB/T2419---2005
5 Test conditions and materials
5.1 The test room, equipment, mixing water and samples shall comply with the relevant provisions of Article 4 of GB/T17671-1999 on test rooms and equipment. 5.2 Mortar composition
The amount of mortar material shall be determined in accordance with the requirements of the corresponding standards or test design. 6 Test method
6.1 If the jumping table is not used within 24 hours, it shall be empty for 25 times in a cycle. 6.2 The preparation of mortar shall be carried out in accordance with the relevant provisions of GB/T17671. While preparing the mortar, wipe the table surface, the inner wall of the test mold, the tamping rod and the utensils in contact with the mortar with a damp cotton cloth, and place the test mold in the center of the table surface and cover it with a damp cotton cloth. 6.3 Quickly load the mixed mortar into the test mold in two layers. The first layer is loaded to about two-thirds of the height of the truncated cone mold. Use a knife to scratch 5 times in two directions perpendicular to each other, and use a tamping rod to tamp and press 15 times from the edge to the center (Figure 1); then, load the second layer of mortar to about 20mm above the truncated cone mold, use a knife to scratch 5 times in two directions perpendicular to each other, and then use a tamping rod to tamp and press 10 times from the edge to the center (Figure 2). After tamping, the mortar should be slightly higher than the test mold. The tamping depth is that the first layer is tamped to half of the height of the mortar, and the second layer is tamped not more than the surface of the tamped bottom layer. When loading and tamping the mortar, hold the test mold steady with your hands and do not let it move. 6.4 After tamping, remove the mold sleeve, tilt the knife, and wipe off the mortar that is higher than the truncated cone mold twice from the middle to the edge at a nearly horizontal angle, and wipe off the mortar that falls on the table. Lift the truncated cone mold vertically upwards and gently. Start the jumping table immediately, and complete 25 jumps within 25s±1s at a frequency of once per second.
6.5 The fluidity test should be completed within 6 minutes from the beginning of adding water to the mortar to the end of measuring the diffusion diameter. 2
Figure 1 Schematic diagram of the tamping position of the first layer
Figure 2 Schematic diagram of the tamping position of the second layer
Results and calculations
GB/T 2419—2005
After the jump is completed, use a caliper to measure the diameters of the two directions perpendicular to each other on the bottom surface of the mortar, calculate the average value, take the integer, and the unit is millimeter. The average value is the fluidity of the cement mortar with this amount of water. GB/T 2419-—2005
A.1 Scope
Appendix A
(Normative Appendix)
Jumping table and its installation
This appendix specifies the technical requirements, installation, lubrication, and verification of the jumping table. A.2 Technical requirements
The jumping table is mainly composed of a cast iron frame and a jumping part (Figure A, 1). A.2. 1
Frame;
Proximity switch;
Motor:
Cam;wwW.bzxz.Net
Pulley;
Push rod;
Disc table top;
8--Tamping rod:
Mold sleeve;
10-·Frustum cone mold.
Figure A, 1 Schematic diagram of jumping table structure
Unit is mm
A.2.2 The frame is a solid whole made of cast iron, with three reinforcing ribs distributed at 120° apart extending the entire height of the frame. The frame hole is finely ground in an annular shape. The axis of the frame hole is perpendicular to the upper surface of the disc. When the disc falls and contacts the frame, the contact surface remains smooth and parallel to the upper surface of the disc, and is in full contact within a 360° range. 4
GB/T2419—2005
A.2.3 The jumping part is mainly composed of the disc table and the push rod, with a total mass of 4.35kg±0.15kg, and is evenly distributed around the push rod. The disc table is cast steel with a Brinell hardness of not less than 200HB, a diameter of 300mm±1mm, and an edge thickness of about 5mm. Its upper surface should be smooth and flat, and hard chrome plated. The surface roughness R. is between 0.8 and 1.6. There is a 125mm diameter engraved circle in the center of the table to determine the position of the conical test mold. There are 8 lines pointing from the outer edge of the disc to the center, distributed at 45° intervals. There are 6 radial ribs under the table, evenly distributed at 60° intervals. The flatness of the disc surface does not exceed 0.10mm. At the moment of the jumping part falling, the support wheel should not contact the cam. The drop distance of the jumping table is 10.0mm ± 0.2mm. The tolerance gap between the push rod and the frame hole is 0.05mm ~ 0.10mm. A.2.4 The cam (Figure A.2) is made of steel, and its outer surface profile conforms to the constant velocity spiral line, and the surface hardness is not less than Rockwell 55HRC. When the push rod and the cam are in contact, no jumping should be detected, and the disc tabletop should be kept stable and not shaken during the rising process. The unit is millimeter
Figure A.2 Cam schematic diagram
A.2.5 The rotating shaft and the synchronous motor with a rotation speed of 60r/min, the rotating mechanism can ensure that the mortar fluidity tester completes 25 jumps within (25±1)s.
A.2.6 The base of the jump table has three holes with a diameter of 12mm to connect with the concrete base. The three holes are evenly distributed on a circle with a diameter of 200mm.
A.3 Installation and lubrication
A.3.1 The jump table should be installed on a hardened horizontal concrete base by expansion bolts. The base is cast with heavy concrete with a bulk density of at least 2240kg/m2. The base is about 400mm×400mm square and about 690mm high. A.3.2 The jump table push rod should be kept clean and lightly lubricated. There should be no oil on the contact surface between the disc and the frame. Applying oil on the cam surface can reduce the friction of operation.
A.4 Verification
After the jump table is installed, use the fluidity standard sample (JBW01-1-1) for verification. If the measured fluidity value of the standard sample is within the specified range with the given fluidity value, the performance of the jump table is qualified.
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