Recently, the Ministry of Transport issued the "Cement and Cement Concrete Test Regulations for Highway Engineering" (JTG 3420-2020) (referred to as the "Regulations"), which will be implemented as a highway engineering industry standard from March 1, 2021. The former "Cement and Cement Concrete Test Regulations for Highway Engineering " (JTG E30—2005) (hereinafter referred to as the former "Regulations") shall be abolished at the same time. In order to facilitate the understanding of the main content of this revision and earnestly implement the work, the relevant revisions are now interpreted as follows:

I . Compilation background     
With the development of our country's highway construction, cement and cement concrete materials and technology have also been developed rapidly, and their related detection technology has also made great progress. Some test methods in the former "Regulations" can no longer meet the actual needs of engineering construction. In order to adapt to the development of the application field and testing technology of cement concrete materials in our country's highway engineering, and to ensure the scientific and advanced nature of cement concrete material testing, the Ministry of Transport organized the revision of the former "Regulations."

II. Positioning of the "Regulations"
The revision of the "Regulations" summarized the advanced research results of over ten years of domestic and foreign road-related fields, combined with the reality of our country's transportation infrastructure, added some content that should be included in the quality inspection of cement and cement concrete during the highway construction process, and deleted some backward test methods on technique or equipment. The "Regulations" strives for reliable test methods, clear test conditions, operable test procedures, scientific calculation formulas, reflecting the level of our country's highway cement and cement concrete test technology, and keeping the same pace with international advanced standards overall.

III. Main content
The main content of this revision

1.The added test method
（1） Cement physical and chemical performance test
1）T 0513-2020 Test method for hydration heat of cement

The heat of hydration is one of the important properties of cement. The size and fluctuation of the heat of hydration of cement will directly affect the performance of cement mortar or cement concrete. Especially for projects with large-volume concrete projects or high-temperature cracking risks, testing is necessary for the heat of hydration of cement, this revision adds advanced dissolution heat method and direct heat test method of cement hydration heat to provide data support for temperature control measures in the construction process.
2）T 0514-2020 Cement chloride ion content test method
3）T 0515-2020 Cement sulfur trioxide content test method (barium sulfate quality method)
4）T 0516-2020 Cement alkali content test method (flame photometric method)

（2）Cement paste performance test
1）T 0517-2020 Test method for bleeding rate between steel wires in cement paste
2）T 0518-2020 Test method for free bleeding rate and free expansion rate of cement paste
3）T 0519-2020 Test method for filling degree of cement paste
4）T 0520-2020 Test method for pressure bleeding rate of cement paste

（3）Performance test of cement concrete mixture
1）T 0531-2020 Test method for pressure bleeding rate of cement concrete mixture
2）T 0532-2020 Test method for slump extension and extension time of cement concrete mixture
3）T 0533-2020 J-ring test method for cement concrete mixture
4）T 0534-2020 V-shaped funnel test method for cement concrete mixture

With the improvement of highway construction technology, large-fluid, self-compacting pumped concrete has been widely used. The traditional slump and expansion cannot characterize the workability of large-fluid, self-compacting concrete. This revision has absorbed the relevant large-fluid concrete index test and detection technology of the United States and Japan, as well as the related advanced technology of the national standard "Ordinary concrete mixture performance test method standard" (GBT 50080-2016) and the current construction industry standard "Self-compacting concrete application technical regulations" (JGJT 283-2012) etc. A V-shaped funnel test method for cement concrete mixture has been formed.

5）T 0535-2020 Test method for vibrating slurry output and loose coefficient of cement concrete mixture
In the low-slump cement concrete (10mm-80mm) slipform construction process, it is difficult to scientifically evaluate the characterization of the workability of the low-slump cement-concrete mixture. According to the principle of cement concrete vibration liquefaction, this revision adds a new test method for cement concrete mixture vibration slurry output. This method is first proposed by our country and included in this regulation, which makes up for the insufficiency of the existing low slump cement concrete workability test method. It is of great significance for controlling the construction performance of slipform paving cement concrete.

6）T 0536-2020 Test method for lateral expansion of cement concrete mixture
After the paver is over, the lateral formwork slides away, and the lateral expansion of the cement concrete is closely related to the vertical formwork characteristic after the cement concrete is vibrated. This revision adds a new test method for the lateral expansion of cement-concrete mixtures. This method is proposed for the first time by our country and incorporated into this regulation, which is of great significance for controlling the construction performance of slipform paving cement concrete.

7）T 0537-2020 Underwater anti-dispersion test method for underwater concrete mixture

8）T 0538-2020 Rapid test method for water-soluble chloride ion content of cement concrete mixture

9）T 0539-2020 Test method for adiabatic temperature rise of cement concrete mixture
The adiabatic temperature rise of concrete is one of the important physical parameters of concrete. In recent years, with the increase of the fineness of cement, the increase of cementitious materials in high-strength concrete, and the increase of structural design dimensions, temperature stress has become the main cause in mass concrete cracks.  The common method for evaluating the cracking risk of the proportion of concrete mixture is to test the adiabatic temperature rise of the cement concrete mixture in advance, and formulate the corresponding temperature control technical plan. This revision adds a new test method for the adiabatic temperature rise of the cement concrete mixture.

（4）Hardened cement concrete performance test
1）T 0566-2020 Test method for bond strength between cement concrete and steel bar
The bond strength between concrete and steel bar is the physical quantity of concrete's ability to resist steel slippage. The bond strength between the two determines the structural performance of reinforced concrete and prestressed concrete. This revision adds the test method for the bond strength between cement concrete and steel bar.  It ensures the quality of highway construction.
2）T 0573-2020 Early cracking sensitivity test method for cement concrete (plate method)
3）T 0574-2020 Test method for shrinkage of cement concrete (contact method)
4）T 0575-2020 Test method for shrinkage of cement concrete (non-contact method)
5）T 0576-2020 The test method for cement concrete limit expansion rate
6）T 0577-2020 Test method for linear expansion coefficient of cement concrete (light lever method)
7）T 0578-2020 Test method for creep of cement concrete
8）T 0579-2020 Test method for resistance to chloride ion penetration of cement concrete (RCM method)
9）T 0580-2020 Test method for resistance to chloride ion penetration of cement concrete (electric flux method)
10）T 0581-2020 Test method for carbonization of cement concrete
11）T 0582-2020 Test method for sulfate corrosion resistance of cement concrete

It is often encountered that cement concrete in the sulphate environment is coupled with the actual environment of the dry and wet cycle conditions at the same time . Sulfate erosion coupled with the dry and wet cycle conditions will damage the cement concrete faster. This revision adds the test method for sulfate corrosion resistance of cement concrete. According to the high temperature instability characteristics of ettringite in cement concrete, the drying temperature in the dry-wet cycle has been also revised, which is different from the specifications of "Standard for Long-term Performance and Durability Test Methods of Ordinary Concrete" (GB/T 50082-2009).

12）T 0583-2020 Test method for salt-freeze resistance of cement concrete (single-side method)

13）T 0584-2020 Test method for bubble spacing coefficient of cement concrete (wire method)

The bubble spacing coefficient is one of the important indicators to characterize the frost resistance of cement concrete. China has successively introduced the concept of bubble spacing coefficient in various industry codes and national standards and stipulated its measurement and calculation methods, including ① The former " Railway Concrete Structure Durability Design Specification (TB 10005—2010) issued by Ministry of Railways ; ② “Technical Regulations for Highway Cement Concrete Pavement Construction” (JTG/T F30—2014) issued by The Ministry of Transport ; ③“Concrete Test for Water Transport Engineering” Technical Specifications for Testing" (JTS/T 236—2019) issued by The Ministry of Transport; ④  "Concrete Test Regulations for Power Generation Engineering" (DL/T 1448-2015) issued by The National Energy Administration; ⑤ "Test Regulations for Hydraulic Concrete" (DL /T 5150—2017) issued by The National Energy Administration; ⑥"Hydraulic Concrete Test Regulations" (SL 352—2006) issued by The Ministry of Water Resources ; ⑦ National standards "Concrete Structure Durability Design Standards" (GB/ T 50476—2019) issued by the Ministry of Construction and the State Administration of Market Supervision and Administration. This revision adds a new test method for the bubble spacing coefficient of cement concrete (wire method).

14）T 0586-2020 Test method for permeability coefficient of cement concrete
（5）The performance test for cement mortar
1）T 0587-2020 Test method for mixing and consistency of cement mortar
2）T 0588-2020 Test method for delamination degree of cement mortar
3）T 0589-2020 Test method for bleeding rate of cement mortar
4）T 0590-2020 Test method for bulk density and air content of cement mortar
5）T 0591-2020 Test method for water retention of cement mortar
6）T 0592-2020 Test method for setting time of cement mortar
7）T 0593-2020 Test method for splitting tensile strength of cement mortar
8）T 0594-2020 Test method for tensile bond strength of cement mortar
9）T 0595-2020 Test method for impermeability coefficient of cement mortar
10）T 0596-2020 Test method for frost resistance of cement mortar

2.Deleted test method
This revision deletes one test method that is basically unnecessary in the former "Regulations": T 0508-2005 cement paste fluidity measurement method (tube ball method)
3.Revised test method
This revision includes:
2 Terms and symbols
T 0501-2005 Cement sampling method
The former "Regulations" did not stipulate the sampling quantity. This revision clearly stipulates that the sampling quality of bagged and bulk cement should be at least 12kg. The "Cement Sampling Method" (GB/T 12573-2008) stipulates that the bagged or bulk sampled quantity is per 1 /10 number should be at least 6kg, the quality of the two is different. This revision clarifies the tonnage of each batch of bagged and bulk cement.
T 0502-2005 Test method for cement fineness (sieve analysis method)
T 0503-2005 cement density test method
T 0504-2005 Test Method for Specific Surface of Cement(Blaine Method)
T 0505-2020 Test method for water consumption, setting time and stability of cement standard consistency
T 0508-2005 Test method for fluidity of cement paste (inverted cone method)
T 0521-2005 Cement concrete mixture mixing and on-site sampling method
T 0522-2005 Test method for consistency of cement concrete mixture (slump meter  test method)
T 0523-2005 Test method for consistency of cement concrete mixture ( Vebe apparatus method)
T 0524-2005 Test method for consistency of roller compacted concrete mixture (improved VC method)
T 0528-2005 Test method for bleeding of cement concrete mixture
T 0526-2005 Test method for air content of cement concrete mixture (mixed air pressure method)
T 0551-2020 Cement concrete specimen production and hardened cement concrete site sampling method
T 0527-2005 Test method for setting time of cement concrete mixture
T 0570-2005 Test method for compressive strength of cement mortar cubes
IV. Precautions for Implementation

1. The user should have a correct understanding of the applicable conditions, specimen producing methods, test conditions, test procedures, and result processing of each test in the "Regulations" for better application in engineering practice.

2. Under special cement and cement concrete or special conditions, when the "Regulations" are not fully applicable, special demonstration and experimental research should be conducted to obtain reliable technical parameters, so that we can implement safely to prevent risks.

3. Carefully organize publicity and implementation training. All provinces (cities, districts) transportation authorities, highway engineering design, construction units, and scientific research institutes should combine local conditions to effectively promote and implement the "Regulations" so that highway builders and managers can correctly understand and use the "Regulations" to provide personnel and technical support for the smooth implementation of the "Regulations".