This Decision promulgates the standard TCXDVN 324:2004 on masonry cement, specifying technical requirements and testing methods. The standard applies to the production and quality inspection of masonry cement.
要点
- Masonry cement is classified according to compressive strength into MC 5, MC 15, and MC 25 grades, with specific technical requirements.
- The water retention capacity of masonry cement is determined through testing methods as per TCXDVN 324-2:2004.
- Masonry cement must be accompanied by a quality inspection certificate upon shipment, including information on technical requirements and product quantity.
- Packaging of cement must ensure that it does not tear or break during transportation and storage.
- The water retention capacity of masonry cement ranges from 80 to 95%.
🌐 本文件的社会影响
- Positive impact: This standard ensures the quality of masonry cement, enhancing the durability and workability of mortar.
- Negative impact: Enterprises must comply with packaging, labeling, transportation, and storage regulations, increasing production costs.
❓ 常见问题
How is masonry cement classified based on compressive strength?
Masonry cement is classified into three grades: MC 5, MC 15, and MC 25, based on the compressive strength value of the standard mortar sample after 28 days of curing.
What is the water retention capacity of masonry cement?
The water retention capacity of masonry cement ranges from 80 to 95%.
What preparations are needed for testing the water retention capacity of masonry cement?
For testing, scales for molds, mortar, and filter paper; tools such as tamping rods, guide tubes, release mechanisms, straightedges, and analytical balances are required.
What information must be included on the quality inspection certificate for masonry cement?
The quality inspection certificate must include the name of the manufacturing facility, the name and grade of cement according to the standard, actual values of technical requirements, quantity of cement, batch number, and date of manufacture.
Can masonry cement be transported together with which chemicals?
Masonry cement shall not be transported together with chemicals that affect its quality.
全文
DECISION
Regarding the issuance of standard TCXDVN 324:2004 - Masonry Cement
THE MINISTER OF CONSTRUCTION
Pursuant to Decree No. 36/2003/NĐ-CP dated 04/4/2003 of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Construction;
Pursuant to the Minutes dated 04/10/2004 of the Inter-Ministerial Scientific and Technical Council for the acceptance of the standard project "Masonry Cement";
Considering the proposal of the Director of the Institute of Building Materials at Circular No. 358/VLXD-KHKT dated October 5, 2004, and the Director of the Science and Technology Department;
DECISION:
Article 1. Issued herewith is 01 Vietnam Construction Standard: TCXDVN 324: 2004 - Masonry Cement.
Article 2. This Decision shall take effect fifteen days from the date of publication in the Official Gazette.
Article 3. The Heads of the Office of the Ministry, the Director of the Science and Technology Department, the Director of the Institute of Building Materials, and the Heads of related units are responsible for implementing this Decision./.
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THE MINISTER
(Signed)
Nguyen Hong Quan
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TCXDVN 324 : 2004
MASONRY CEMENT
Masonry cement
MASONRY CEMENT - PART 1: SPECIFICATIONS
Masonry cement – Part 1: Specifications
1. Scope of Application
This standard specifies the composition and quality requirements of masonry cement used for making mortar for masonry and finishing.
2. Referenced documents
- TCVN 6882 : 2001 Mineral admixtures for cement
- TCVN 4787 : 2001 Cement - Sampling and preparation of test specimens
- TCVN 6016 : 1995 Cement - Method for determination of compressive strength
- TCVN 6017 : 1995 Cement - Methods for determination of setting time and volume stability
- TCVN 4030 : 2003 Cement - Fineness determination method
- TCVN 141 : 1998 Cement - Chemical analysis method
- TCXDVN …-2 : 2004 Masonry cement - Part 2: Water retention test method
3. General Provisions
3.1. Masonry cement is a hydraulic binding powder consisting of Portland cement clinker and mineral admixtures, which may include organic additives. When mixed with sand and water without additional materials, it produces fresh mortar suitable for masonry and finishing work.
3.2. Water retention capacity is the amount of water retained in the mortar when in contact with water-absorbing material compared to the initial water content in the mortar.
3.3. Mineral admixtures shall comply with the provisions of TCVN 6882 : 2001.
3.4. Classification
Masonry cement is classified according to compressive strength into grades MC 5, MC 15, and MC 25, wherein:
- MC is the conventional symbol for masonry cement.
- The values 5, 15, and 25 represent the compressive strength of the standard mortar sample after 28 days of curing, expressed in N/mm2 (MPa), determined according to TCVN 6016: 1995.
3.5. Composition
The composition of masonry cement includes Portland cement clinker, mineral admixtures, and organic additives (if necessary), as specified in Table 1.
Table 1 - Composition of masonry cement
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Composition |
Type of cement |
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MC 5 |
MC 15 |
MC 25 |
|
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Portland cement clinker, %, not less than |
25 |
40 |
|
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Organic additives, %, not more than |
1 |
||
4. Technical requirements
Quality requirements for masonry cement are specified in Table 2.
Table 2 - Quality requirements for masonry cement
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Name of Index |
Level |
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MC 5 |
MC 15 |
MC 25 |
|
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1. Compressive strength, N/mm2 (MPa), not less than: 7 days ± 4 hours 28 days ± 8 hours |
- 5 |
9 15 |
15 25 |
|
2. Setting time, Initial, minutes, not less than Final, hours, not more than |
60 10 |
||
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3. Fineness, residue on sieve 90Granite, gabbro, decorative stone...m, %, not more than |
12 |
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4. Volume stability, determined by the Le Chatelier method, mm, not more than |
10 |
||
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5. Anhydrous sulfur trioxide (SO3), %, not more than |
2 |
3 |
3 |
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6. Chloride (Cl-), %, not more than |
0,1 |
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7. Water retention capacity, %, |
From 80 to 95 |
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5. Testing method
5.1. Sampling and preparation of test specimens according to TCVN 4787: 2001
5.2. Compressive strength determined according to TCVN 6016: 1995 but with a loading rate of (400 ± 40) N/s.
5.3. Setting time and volume stability determined according to TCVN 6017: 1995
5.4. Fineness determined according to TCVN 4030: 2003
5.5. Anhydrous sulfur trioxide (SO3) and chloride (Cl-) determined according to TCVN 141: 1998
5.6. Water retention capacity determined according to TCXDVN ….. -2: 2004
6. Packaging, labeling, transportation, and storage
6.1. Upon leaving the factory, masonry cement must be accompanied by a quality inspection certificate containing:
- Name of the production facility;
- Product name and grade according to this standard;
- Actual values of the quality requirements according to Article 4;
- Quantity of cement shipped and batch number;
- Date of manufacture.
6.2. Packaging
6.2.1. The bag containing cement must ensure that the quality of the cement is not reduced, and it must not tear or break during transportation and storage.
6.2.2. The net weight of each bag of cement is (25 ± 0.5) kg.
Annotation - Other types of bags with different weights from those specified in Clause 6.2.2 or bulk cement may be used.
6.3. Labeling
On the outer surface of the cement bag, in addition to the registered trademark, the following information must be clearly marked:
- Product name produced according to this standard;
- Grade of cement according to this standard;
- Net weight of the cement bag;
- Name of the production facility;
- Batch number;
- Date of manufacture.
6.4. Transportation
6.4.1. Cement must not be transported together with chemicals that affect its quality.
6.4.2. Bagged cement must be transported using vehicles with rain and moisture protection.
6.4.3. Bulk cement must be transported using specialized vehicles or other vehicles with careful covering.
6.5. Storage
6.5.1. The warehouse storing bagged cement must be dry, clean, have a raised floor, solid walls and roof, and easy access for vehicles. Bags of cement must be stored at least 20 cm away from the walls and floor, and separated by batches.
6.5.2. The silo for bulk cement must be able to store cement separately by type.
6.5.3. Masonry cement is warranted for 60 days from the date of manufacture.
MASONRY CEMENT - PART 2:
TEST METHOD FOR WATER RETENTION
Masonry cement – Part 2: Test method for water retention
1. Scope of Application
This standard specifies the method for determining the water retention capacity of masonry cement.
2. Referenced documents
TCVN 6016: 1995 Cement - Method for determination of compressive strength
3. Principles
3.1. Water retention capacity is determined by the loss of water from standard consistency mortar placed on filter paper.
3.2. Standard consistency mortar is mortar with sufficient plasticity to resist the penetration of a standard needle to a predetermined depth.
4. Equipment and tools
- Analytical balance, accuracy 0.1g.
- Graduated cylinder or burette, capable of measuring volume accurately to 1%.
- Metal ruler, length 300 mm, width 30 mm, thickness 2 mm.
- Mixer, complying with the requirements of TCVN 6016:1995.
- The penetration tool has a structure and size as shown in Figure 1. The shape of the base (1) allows for placing the sample mold (8) at the center position below the standard needle (7). The sample mold is made of metal, cylindrical with a bottom, inner diameter (80 ± 1) mm, depth (70 ± 1) mm. The standard needle is made of stainless steel, diameter (25 ± 0.5) mm, length (77 ± 1) mm, with a spherical tip. The total weight of the measuring rod (6) and the standard needle (7) is (90 ± 2) g. The release mechanism (5) holds the measuring rod (6) in its initial position such that the lower end of the standard needle (7) is just above the surface of the mortar before testing.
- The compaction rod is made of metal, weighing (250 ± 5) g, with a structure and size as shown in Figure 2.
- A metal cylindrical mold with a bottom, inner diameter (100±1) mm, depth (25 ± 1) mm.
- A heavy object weighing 2 kg.
- A flat, non-absorbent plate, diameter (110 ± 5) mm, thickness 5 mm.
- Cotton fabric pieces type (100 ¸120) g/m22, circular, diameter (100 ± 1) mm.
- Filter paper pieces type (180¸200) g/m22, circular, diameter (100 ± 2, diameter (100
1. 1) mm. Used filter papers shall not be used.
2. Base
3. Support frame
4. Clamp bar
5. Guide tube
6. Release mechanism
7. Measuring rod with scale markings
8. Standard needle
Sample mold
Figure 1. Penetration tool
5. Figure 2. Compaction rod
Procedure
5.1 Preparation of mortar with standard consistency
5.1.1. Mortar preparation
Mortar is prepared according to the process described in TCVN 6016: 1995 but the amount of water must be determined to achieve the required consistency (the initial mixing water volume is approximately 225 ml). Before starting the test, the standard needle and the sample mold should be wiped clean with a damp cloth.
5.1.2. Pouring mortar into the mold0 After mixing, pour the mortar into the sample mold in two layers. Compact each layer gently 10 times using the compaction rod. Use a straightedge to remove excess mortar on the surface of the mold by holding it at a 45
degree angle and moving it in a sawing motion until the mortar fills the mold, then smooth the surface of the mold gently once in the opposite direction, ensuring the mortar is level with the top of the mold.
5.1.3. Testing the needle penetration depth Immediately after smoothing the surface of the mortar, place the sample mold on the base of the penetration tool directly under the standard needle. Adjust the measuring rod using the release mechanism so that the lower end of the needle touches the surface of the mortar. Allow the standard needle to fall freely from its initial position directly above the surface of the mortar into the center of the mortar mass.
Determine the value of the needle penetration depth into the mortar mass by reading the scale marks on the measuring rod at 30 seconds after releasing the needle, rounding off to the nearest millimeter. The time from the completion of mortar mixing to the release of the needle should not exceed (150 ± 15) seconds.
Mortar achieves standard consistency when the needle penetration depth is (35 ± 3) mm.
If the mortar does not meet the standard consistency, a new batch of mortar must be mixed with a different amount of water. Repeat the test with the newly mixed batch until the needle penetration depth reaches (35 ± 3) mm in two consecutive tests.
Record the required amount of water (m5) in grams to achieve standard consistency and the needle penetration depth in millimeters.
5.2 Determination of water retention capacity
Immediately after preparing the mortar with standard consistency, remix the remaining mortar in the mixer at low speed for 15 seconds, then proceed with the test. The time from the start of mortar mixing to the water retention test should not exceed 10 minutes.
Clean the cylindrical mold, weigh it accurately to 1 g, obtaining a weight (m1). Weigh eight pieces of filter paper accurately to 0.1 g, obtaining a weight (m2).
Pour the mortar into the cylindrical mold, filling it higher than the height of the mold without compressing or vibrating too strongly. Use a straightedge to remove excess mortar on the surface of the mold by holding it at a 450 degree angle and moving it in a sawing motion until the mortar fills the mold, then smooth the surface of the mold gently once in the opposite direction. Wipe the outside of the mold with a cloth.
Weigh the mold and mortar accurately to 1 g, obtaining a weight (m3).
Cover the surface of the mortar with two pieces of cotton fabric and place eight pieces of filter paper on top of the fabric. Place the hard plate on top of the filter paper, invert the mold onto a flat surface, and place the 2 kg weight on the bottom of the mold.
After 5 minutes ± 5 seconds, remove the 2 kg weight, invert the mold again, remove the hard plate, filter paper, and cotton fabric. Weigh the wet filter paper pieces accurately to 0.1 g, obtaining a weight (m4).
6. Calculation of results
The weight of the mortar used in the test is (m3 – m1), in grams.
The weight of water in the mortar (M), in grams, is calculated by the formula:
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M = |
Granite, gabbro, decorative stone...5(m3 – m1) |
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1350 + 450 + m5 |
Where:
Granite, gabbro, decorative stone...1 where m
Granite, gabbro, decorative stone...3 is the weight of the cylindrical mold, in grams
Granite, gabbro, decorative stone...5 is the weight of the mold and mortar, in grams
is the weight of water used in the standard consistency test, in grams
1350 is the weight of sand when mixing mortar, in grams
450 is the weight of cement when mixing mortar, in grams4 – m2), in grams.
The weight of water absorbed by the filter paper pieces is (m
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The water retention capacity of the mortar (X), in percent, is calculated by the formula: |
[X =4 – m2)]M – (m |
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Briefly describe technical improvements, production processes, raw materials, designs; new technology applications such as automation, digitalization, clean technology; management, marketing, distribution solutions; products winning awards or certifications related to innovation…):… |
Where:
Granite, gabbro, decorative stone...2 ) x 100
Granite, gabbro, decorative stone...4 where m
is the weight of eight pieces of filter paper before absorbing water, in grams
is the weight of eight pieces of filter paper after absorbing water, in grams
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