中国沥青气候分区与标号选择 · Climate Zones and Grade Selection under JTG F40
摘要 · Summary
JTG F40 用三位代码表示工程所在地的气候分区：第一位是夏季高温分区，按最热月平均最高气温分为1（高于30℃）、2（20–30℃）、3（低于20℃）；第二位是冬季低温分区，按极端最低气温分为1（低于-37℃）至4（高于-9℃）；第三位是雨量分区，按年降雨量分为1（大于1000毫米）至4（小于250毫米）。代码读作1-4-1或2-2-2。夏热推向硬标号，冬寒推向软标号，两端同时极端时须用改性沥青。
JTG F40-2004《公路沥青路面施工技术规范》 assigns every project location a three-part climate zone code (气候分区). The first digit is the summer high-temperature zone (夏季高温分区), taken from the mean maximum air temperature of the hottest month: 1 above 30 °C, 2 between 20 and 30 °C, 3 below 20 °C. The second digit is the winter low-temperature zone (冬季低温分区), taken from the extreme minimum air temperature: 1 below -37 °C, 2 from -37 to -21.5 °C, 3 from -21.5 to -9 °C, 4 above -9 °C. The third digit is the rainfall zone (雨量分区), taken from annual precipitation: 1 above 1000 mm, 2 from 500 to 1000 mm, 3 from 250 to 500 mm, 4 below 250 mm. A code therefore reads as 1-4-1 or 2-2-2. A high summer division pushes the grade selection toward the harder end of the 道路石油沥青 series, an extreme winter division pushes it toward the softer end, and a location that is severe at both ends is where an unmodified binder runs out of range and a modified binder (改性沥青) becomes necessary rather than optional.
三位代码是什么 · What the code is, where it comes from, and how to read it
The climate zone code is the part of the Chinese system that has no counterpart on a Middle East technical data sheet, and it is the field most often left blank on an enquiry. It is not a grade, not a quality class and not a preference — it is a classification of the place the pavement will be built.
JTG F40-2004《公路沥青路面施工技术规范》 does not name a binder grade for a given city. It classifies the location against three climatic variables, and the resulting code then narrows what can sensibly be specified there and tightens some of the requirement limits the chosen grade must meet. The instrument is the climate zone code (气候分区), written as three digits separated by hyphens — 1-4-1, 2-2-2, 2-3-2 — in which each digit is a division of a different variable.
The order never changes, and it is worth committing to memory, because the whole framework inverts if the digits are read in the wrong sequence:
- 第一位 · First digit — 夏季高温分区, the summer high-temperature zone, derived from the mean maximum air temperature of the hottest month (最热月平均最高气温).
- 第二位 · Second digit — 冬季低温分区, the winter low-temperature zone, derived from the extreme minimum air temperature (极端最低气温).
- 第三位 · Third digit — 雨量分区, the rainfall zone, derived from annual precipitation (年降雨量).
为什么是这三个变量 · Why these three variables and not others
Each digit is aimed at one dominant failure mode, and between them they cover the three ways an asphalt pavement actually fails in service.
The summer digit is about permanent deformation — rutting (车辙). A binder that is too soft for its summer climate loses stiffness under repeated wheel loads and the surface deforms into wheelpaths, most visibly at intersections, on grades and wherever heavy traffic is channelised. The hottest-month mean maximum is used rather than an all-time record because rutting is an accumulation problem: it is driven by how hot the pavement gets routinely across a season, not by one exceptional afternoon.
The winter digit is about low-temperature cracking (低温开裂). As a pavement cools it wants to contract, the layer beneath restrains it, and tensile stress builds in the binder. If the binder has gone brittle before the stress is relieved, it cracks — typically as transverse cracks at regular spacing across the carriageway. Here the standard uses the extreme minimum rather than an average, because thermal cracking is a single-event problem: one severe night is enough to open a crack that then stays open and admits water for the rest of the pavement’s life.
The rainfall digit is about moisture damage (水损害) — the progressive loss of adhesion between binder and aggregate under repeated wetting, which strips the film from the stone and unravels the mix from within. It is the only one of the three that is not primarily a binder-consistency question, and it is treated differently below.
分区名称 · The divisions have names, not only numbers
Chinese project documents frequently write the division name rather than the digit, and a supplier reading a tender in Chinese should recognise both forms. The summer divisions are 夏炎热区, 夏热区 and 夏凉区 — hot, warm and cool summer. The winter divisions are 冬严寒区, 冬寒区, 冬冷区 and 冬温区 — severe, cold, cool and mild winter. The rainfall divisions are 潮湿区, 湿润区, 半干区 and 干旱区 — humid, moist, semi-arid and arid. A document that says 夏炎热冬温潮湿区 is describing exactly the same thing as the code 1-4-1.
怎么读一个代码 · Reading a code, worked through
Take the two codes that appear most often as illustrations:
- 1-4-1 — first digit 1: the hottest month averages a daily maximum above 30 °C, so summers are hot. Second digit 4: the extreme minimum air temperature stays above -9 °C, so winters are mild. Third digit 1: annual precipitation exceeds 1000 mm, so the climate is humid. In one line: hot summers, mild winters, heavy rainfall. The binder problem here is rutting and moisture damage; low-temperature cracking is barely a constraint.
- 2-2-2 — first digit 2: hottest-month mean maximum between 20 and 30 °C, so summers are warm rather than fierce. Second digit 2: extreme minimum between -37 and -21.5 °C, so winters are genuinely severe. Third digit 2: annual precipitation between 500 and 1000 mm. In one line: moderate summers, severe winters, moderate rainfall. The binder problem here is thermal cracking, and the selection moves the opposite way from 1-4-1.
- 2-3-2 — warm summers, winter minima between -21.5 and -9 °C, moderate rainfall. Neither temperature end is extreme. This is the comfortable middle of the framework, and it is the territory where 70# does most of its work.
一个统一规律 · One rule that holds in all three positions
In every position of the code, the digit 1 marks the most demanding end of that variable: the hottest summer, the coldest winter, the wettest climate. This is worth stating because the winter digit trips people up constantly. A second digit of 1 is not a mild winter — it is the most severe winter division in the system, below -37 °C. A second digit of 4 is the mild one. The numbers run from severe to benign, not from cold to hot.
常见误读 · Four ways the code is misread
- Treating it as a property of a city. The code belongs to the project location. Elevation, distance from the coast and terrain move it, and a single province can contain more than one code — a coastal alignment and a mountain pass in the same administrative region are not the same climatic problem. Take the code from the project documents, not from a supplier’s estimate based on a city name.
- Treating it as a grade. The code is an input to the selection, alongside traffic loading, highway class and which pavement layer the binder is going into. It narrows the answer; it does not produce it by itself.
- Assuming all combinations exist. Three summer divisions, four winter divisions and four rainfall divisions give 48 arithmetic combinations, but only a subset occurs on the ground. A cool-summer, mild-winter, arid location is not a common climate anywhere.
- Assuming the digits are independent of the specification. They are not. Some of the JTG F40 acceptance limits are written per climate zone, which is covered in the next section and is the reason the code matters commercially rather than only academically.
三位代码的全部分区与界限 · Every division and its boundary, digit by digit
The complete set of divisions defined in the JTG F40 climate zone framework, with the meteorological basis of each digit and what each division means for the pavement. Read down the block for one digit at a time.
| 代码位 · Code position | 分区 · Division | 依据 · Basis | 界限 · Boundary | 工程含义 · What it means for the pavement |
|---|---|---|---|---|
| 第一位 First digit | 1 · 夏炎热区 Hot summer | 最热月平均最高气温 Hottest-month mean maximum air temperature | above 30 °C | Rutting is the governing risk; the selection moves toward the harder grades and softening point and 60 °C viscosity carry the decision |
| 第一位 First digit | 2 · 夏热区 Warm summer | 最热月平均最高气温 Hottest-month mean maximum air temperature | 20–30 °C | Rutting is a real but manageable risk; the mainstream grade normally serves |
| 第一位 First digit | 3 · 夏凉区 Cool summer | 最热月平均最高气温 Hottest-month mean maximum air temperature | below 20 °C | High-temperature performance stops being the constraint; the winter digit governs the choice |
| 第二位 Second digit | 1 · 冬严寒区 Severe winter | 极端最低气温 Extreme minimum air temperature | below -37 °C | Thermal cracking dominates; only the softest grades remain in range, and an unmodified binder is at the edge of what it can do |
| 第二位 Second digit | 2 · 冬寒区 Cold winter | 极端最低气温 Extreme minimum air temperature | -37 to -21.5 °C | Thermal cracking is the leading risk; low-temperature ductility and the ageing residue block do the gatekeeping |
| 第二位 Second digit | 3 · 冬冷区 Cool winter | 极端最低气温 Extreme minimum air temperature | -21.5 to -9 °C | Low-temperature requirements are live but satisfiable by a conventional grade |
| 第二位 Second digit | 4 · 冬温区 Mild winter | 极端最低气温 Extreme minimum air temperature | above -9 °C | Cracking is not the constraint; the summer digit and the traffic loading decide |
| 第三位 Third digit | 1 · 潮湿区 Humid | 年降雨量 Annual precipitation | above 1000 mm | Moisture damage and stripping are the leading durability risk; binder–aggregate adhesion becomes a first-order question |
| 第三位 Third digit | 2 · 湿润区 Moist | 年降雨量 Annual precipitation | 500–1000 mm | Seasonal moisture damage; adhesion checked as routine and drainage designed for |
| 第三位 Third digit | 3 · 半干区 Semi-arid | 年降雨量 Annual precipitation | 250–500 mm | Water is a lesser problem; oxidative ageing and large diurnal temperature swing take over |
| 第三位 Third digit | 4 · 干旱区 Arid | 年降雨量 Annual precipitation | below 250 mm | Durability, solar exposure and ageing rather than water; the ageing residue requirements carry more weight |
代码如何决定标号 · How the zone code drives the grade selection
The mechanism is simple to state and easy to get backwards. The two temperature digits act on the same single property — binder consistency — and they act on it in opposite directions.
第一位把选择往硬处推 · The summer digit pushes toward a harder grade
A hot summer division means the pavement spends long periods at temperatures where the binder contributes little stiffness and the mix relies on aggregate interlock to carry the wheel load. The counter-measure at the binder end is to start harder, so that the binder still has stiffness left at service temperature. Along the 道路石油沥青 series that means moving down the numbers: from 70# toward 50#, and to 30# for heavy-duty and high-modulus base work.
Before those numbers can be read as directions, one convention has to be fixed, because getting it wrong inverts every sentence that follows. In the Chinese series the number carried with a hash is a nominal penetration, and the acceptance band is written around it — it is not the band itself. 70# is not penetration 70 and it is not 60-to-70: it is penetration 60–80 (0.1 mm), with 70 sitting in the middle. The same construction runs through the series — 50# is 40–60, 30# is 20–40, 90# is 80–100, 110# is 100–120, 130# is 120–140. An ASTM designation such as 60/70 works the opposite way round, where the two printed numbers are the limits. So when this page says a hot zone pushes the selection from 70# to 50#, the real movement is from a 60–80 band to a 40–60 band, and a reader who has silently assumed the ASTM convention will place both grades in the wrong position relative to each other and to the requirement.
It also shifts which requirement lines matter. In a hot zone, the lines that decide whether a binder will hold the surface are 软化点 — softening point, minimum 46 °C for 70# A级 rising to 49 °C at 50# and 55 °C at 30# — and 60 ℃ 动力粘度, the dynamic viscosity at 60 °C, which is minimum 180 Pa·s for 70# A级. Sixty degrees is close to the temperature of a hot surface layer in service, which makes that line a far more direct rutting indicator than penetration at 25 °C. It is also one of the two properties, with wax content, most often absent from an export laboratory report.
第二位把选择往软处推 · The winter digit pushes toward a softer grade
A severe winter division means the pavement will be driven to temperatures where the binder becomes glassy. The counter-measure is the opposite: start softer, so the binder retains some capacity to relax stress before it fractures. Along the series that means moving up the numbers — 90# (penetration 80–100), 110# (100–120), 130# (120–140).
The requirement lines that matter also change. In a cold zone the decisive lines are 10 ℃ 延度, the ductility at 10 °C, and the ductility of the residue after ageing — and, critically, both of those limits are written per quality class and per climate zone in JTG F40. The 针入度指数 PI window of -1.5 to +1.0 at 70# is doing related work: PI describes how sharply a binder changes consistency as the temperature moves, and a strongly negative PI is exactly the behaviour a wide-swinging climate cannot tolerate. So is the ageing residue block — mass change within ±0.8 % and a retained penetration ratio of at least 61 % for 70# A级, 57 % at 90#, 54 % at 110# — because a binder that hardens sharply during plant mixing arrives on the road already part-aged and cracks a winter or two earlier than the design assumed.
代码不只是建议，它写回技术要求 · The code is written into the acceptance limits
This is the commercially decisive point and it is the reason a supplier must ask for the code rather than treat it as background colour. The ductility requirement at 10 °C and the residue ductility limits after RTFOT or TFOT are not single national figures — they are tabulated against quality class and climate zone. A certificate of analysis issued against JTG F40 without knowing the zone is therefore incomplete on precisely the lines a cold-region project will retest first. An offer that quotes only a grade and a class has left one of the three inputs blank.
用的是气温，不是路面温度 · Air temperature, not pavement temperature
A recurring error is to treat the zone code as a Chinese dialect of Superpave performance grading. It is not, and the difference is structural rather than a matter of units. The JTG F40 divisions are defined on air temperature statistics, measured at a meteorological station. A performance grade such as PG 64-22 is defined on pavement temperature — the high criterion at a design pavement temperature within the asphalt layer, the low criterion at a design pavement low temperature — and it is established by running a dynamic shear rheometer and a bending beam rheometer on that specific binder.
Two consequences follow. A zone code cannot be arithmetically converted into a PG grade, because the pavement is hotter than the air in summer and the relationship depends on depth, colour, wind and solar radiation. And a PG grade does not discharge a JTG F40 requirement, because JTG F40 asks for penetration, ductility at stated temperatures, wax content, solubility, flash point and the ageing residue block by JTG E20-2011 methods, none of which a PG certificate reports. Where both systems appear in one tender, they have to be satisfied separately, on their own test data.
分区只是其中一个输入 · The zone is one input among several
Climate narrows the answer. It does not finish it. Three other inputs sit alongside it and can override the climatic direction entirely:
- 交通荷载 · Traffic loading. A hot zone carrying light rural traffic is a different problem from a hot zone carrying channelised heavy trucks on a grade. Heavy, slow, channelised loading is what actually converts a hot summer into a rut, and it is the reason a project in a 2-x-x zone may still specify 50#.
- 路面层次 · Pavement layer. Surface, intermediate, lower and base layers see different temperatures and different stresses, and a project routinely specifies different grades in different layers of the same pavement. The quality class permission is written per layer as well: A级 is permitted for all layers, B级 for the lower layers of expressways and class-1 highways and all layers of lower classes, C级 for class-2 highways and below.
- 混合料类型 · Mix type. A dense-graded wearing course, a stone-matrix mix and an asphalt-treated base do not ask the same thing of the binder, and the mix design can compensate in directions the binder grade cannot.
按分区组合的标号方向 · Selection guide by zone combination
The table reads the first two digits together, because that is how the decision is actually made — the third digit is handled separately below and does not select the grade. Read each row as the direction the climate pushes the selection, then apply traffic loading and pavement layer on top of it.
| 分区代码 · Code pattern | 气候特征 · Climate described | 主导风险 · Governing risk | 标号方向 · Direction of selection | 同时收紧的指标 · What tightens alongside |
|---|---|---|---|---|
| 1-4-x | 夏炎热、冬温 — hot summers above 30 °C with mild winters above -9 °C | 车辙 Rutting, and moisture damage where the third digit is 1 | Toward the hard end: 50#, or the harder half of the 70# band; 30# considered for heavy-duty and high-modulus base layers | Softening point and 60 °C dynamic viscosity carry the decision; the low-temperature lines are comfortably satisfied |
| 1-3-x | 夏炎热、冬冷 — hot summers with winter minima between -21.5 and -9 °C | 车辙为主，低温为次 Rutting leading, cracking secondary | 70# as the mainstream answer, moving to 50# where traffic is heavy, slow or channelised | Both ends remain within reach of an unmodified binder — this is why this belt carries most of the volume |
| 2-4-x | 夏热、冬温 — summers 20–30 °C with mild winters | 耐久性与车辙 Durability with a moderate rutting risk | 70#, with 90# where loading is light and the mix design supports it | The least climatically constrained combination; traffic loading and layer position drive the choice more than climate does |
| 2-3-x | 夏热、冬冷 — warm summers with cool winters | 两端均中等 Neither end extreme | 70# mainstream; 90# where the winter minimum sits at the cold edge of its band | Ductility at 10 °C stops being a formality and becomes a line to check on the certificate |
| 2-2-x | 夏热、冬寒 — warm summers with winter minima from -37 to -21.5 °C | 低温开裂 Thermal cracking | Toward the soft end: 90#, and 110# where the winter minimum approaches the lower boundary | Ductility at 10 °C, residue ductility after ageing and the PI window do the real gatekeeping |
| 2-1-x and 3-1-x | 冬严寒 — winter minima below -37 °C, with warm or cool summers | 低温开裂，压倒性 Thermal cracking, dominant | The softest grades in the series: 110# and 130# | An unmodified binder is at the limit of its range here; modified binder is common and often specified outright |
| 1-2-x and 1-1-x | 夏炎热与冬寒并存 — hot summers above 30 °C together with winter minima below -21.5 °C | 两端同时 Both ends at once | No single unmodified grade serves both ends — this is the combination where 改性沥青 becomes necessary rather than preferable | Everything tightens at once: high-temperature stiffness and low-temperature flexibility are demanded of the same binder |
| 3-x-x | 夏凉 — hottest-month mean maximum below 20 °C, characteristically high-altitude | 低温与耐久 Low temperature and durability | Softer grades; the summer digit removes the rutting constraint and the winter digit governs entirely | Read the pair, not the first digit alone — a cool summer is usually paired with a severe winter, and often with a large diurnal swing |
雨量分区控制的是什么 · What the third digit actually controls
The third digit is the one most often ignored by suppliers, because it does not move the grade. It moves something else that decides whether the pavement survives: the adhesion between the binder and the aggregate, and the design provisions built around it.
| 雨量分区 · Rainfall zone | 年降雨量 · Annual precipitation | 主要问题 · Dominant problem | 在设计中驱动什么 · What it drives in the design | 对采购的影响 · What it means for the purchase |
|---|---|---|---|---|
| 1 · 潮湿区 Humid | above 1000 mm | 水损害与剥落 Moisture damage and stripping | Binder–aggregate adhesion provisions, anti-stripping treatment such as hydrated lime or an additive, drainage and permeability design, and mixture-level water sensitivity testing under JTG E20 | Ask for an adhesion result against the project’s own aggregate, not a general claim. Adhesion is a property of the pair, not of the binder alone, and no penetration or softening point value predicts it |
| 2 · 湿润区 Moist | 500–1000 mm | 季节性水损害 Seasonal moisture damage | Adhesion checked as routine, drainage still explicitly designed, water sensitivity testing normally retained | The same adhesion question applies, with less margin lost if it is answered late. It should still be answered before the cargo loads |
| 3 · 半干区 Semi-arid | 250–500 mm | 氧化老化与温差 Oxidative ageing and diurnal swing | Durability provisions rather than water provisions; clear skies and a wide daily temperature range increase oxidation and thermal fatigue | The ageing residue block carries more weight — mass change within ±0.8 % and the retained penetration ratio are the lines to check first on the certificate |
| 4 · 干旱区 Arid | below 250 mm | 老化、日照与温差 Ageing, solar exposure and diurnal swing | Durability and ageing resistance; moisture damage recedes as a design driver, and the temperature swing between day and night can exceed the seasonal swing elsewhere | Ageing performance and temperature susceptibility, meaning the PI window and the residue requirements, matter more than any high-temperature line taken alone |
中国各区域的定性特征 · A qualitative regional picture
The descriptions below are qualitative and deliberately so. A climate zone code belongs to a project location rather than to a province or a city, and elevation, terrain and distance from the coast move it within a short distance. Use these to understand the shape of the problem, and take the actual code from the project documents.
东北 · The northeast
An extreme low-temperature environment. The winter digit dominates the binder decision here, and the selection moves toward the soft end of the series — 90#, 110# and, where the extreme minimum is severe enough, 130#. Low-temperature ductility and the ageing residue limits are the acceptance lines that decide the cargo, not softening point.
华南与海南 · The far south
A high-temperature, humid environment: hot summers, mild winters and heavy rainfall, the pattern that a 1-4-1 style code describes. Two things run in parallel — hard-end grade selection to resist rutting, and serious attention to binder–aggregate adhesion and drainage because of the rainfall digit.
长江中下游 · The middle and lower Yangtze
Hot, humid summers with winters that are cold but not severe. A rutting-led problem with a real but satisfiable low-temperature requirement, and a wet third digit. This is mainstream 70# country, moving harder where traffic is heavy and channelised.
华北 · The north China plain
Hot summers paired with winters that are genuinely cold without reaching the severest division, and moderate rainfall. Both temperature ends are live constraints at once, which puts weight on temperature susceptibility — the penetration index window — rather than on either extreme alone.
西北内陆 · The northwest interior
Continental and arid: a large annual and diurnal temperature swing, low precipitation and strong solar exposure. This is the region where the summer and winter digits most often pull hard against each other, and where the modified-binder question arises from climate rather than from traffic.
青藏高原 · The Tibetan plateau
High altitude, so summers are cool while winters are severe. The first digit removes the rutting constraint and the second digit governs completely. Add intense solar radiation, a very large day–night swing and, in places, frozen ground beneath the structure, and durability becomes as important as consistency.
把分区代码用进询价 · Turning a zone code into a checkable enquiry
A grade name on its own cannot be checked. A grade name with a class, a layer and a climate zone code can be checked line by line before anything loads, which is the entire point of asking for it.
1. 从项目文件取代码 · Take the code from the project documents
The climate zone code belongs to the project location and appears in the design and tender documents. Do not accept a code inferred from a city name in an email, and do not infer one yourself — a coastal alignment and a mountain section in the same province can carry different codes, and the code determines which acceptance limits apply.
2. 同时说明等级与层次 · State the quality class and the pavement layer with it
The zone code narrows the grade; the highway class and pavement layer decide the permitted quality class. A级 is permitted for all grades and all layers, B级 for the lower layers of expressways (高速公路) and class-1 highways (一级公路) and all layers of lower classes, and C级 for class-2 highways (二级公路) and below. The three fields together define what has to be proved.
3. 指明随分区变化的指标 · Identify the limits that move with the zone
The ductility requirement at 10 °C and the residue ductility limits after ageing are tabulated against quality class and climate zone. Ask for those specific limits from the edition of the standard named in the project, and have the certificate of analysis report the measured values against them rather than against a generic export range.
4. 按 JTG E20 试验 · Have the testing done to the Chinese methods
Chinese acceptance testing is performed to JTG E20-2011《公路工程沥青及沥青混合料试验规程》 — T 0604 penetration, T 0605 ductility, T 0606 softening point, T 0607 solubility, T 0611 flash point, T 0615 wax content by distillation, T 0609 TFOT, T 0610 RTFOT, T 0620 dynamic viscosity at 60 °C, T 0603 density. Where an ASTM method is cited alongside, the two are equivalent in intent and not identical in procedure, and on a marginal line that difference is what turns a pass into a fail at the destination laboratory.
5. 早点决定普通还是改性 · Settle unmodified versus modified early
If the first two digits are both at severe divisions, no unmodified grade in the series serves both ends and the project will need a modified binder. That is a different product, a different requirement table inside JTG F40 and a different commercial conversation. It is far cheaper to establish this at enquiry stage than after a conventional cargo has been offered and priced.
6. 蜡含量按目的地分区来看 · Read the wax content against the destination’s zone
Wax content (蜡含量), determined by distillation under T 0615, is the gate that sets the quality class — a maximum of 2.2 % for A级, 3.0 % for B级 and 4.5 % for C级 — and it is decided by the crude slate rather than by refinery diligence. Naphthenic crude yields naturally low-wax bitumen and is the domestic quality benchmark in China, while many Middle East crude slates are more paraffinic and give a higher wax content. That is the single biggest technical barrier for Middle East material entering this market, and it has to be said plainly rather than worked around. What belongs on this page is why it lands hardest on a cold-zone enquiry: wax raises the temperature at which the binder stiffens abruptly and worsens its temperature susceptibility, which is precisely the behaviour the ductility requirement at 10 °C and the PI window of -1.5 to +1.0 exist to police. The same cargo can sit comfortably inside a 1-4-x specification and fail those two lines in a 2-2-x one. Measure the figure against the zone the material is actually going to before an offer is built around it.
7. 确认标准版本与省级技术文件 · Confirm the edition, and ask about the provincial document
Ask which edition of JTG F40 the tender names, because the selection provisions and the zone-dependent limit tables belong to an edition and not to the standard in the abstract. Then ask whether the provincial transport department has issued its own technical document for the route. Provincial documents exist in large part because climate varies inside a single province, and they characteristically narrow the grades permitted for a given zone or tighten individual limits above the national requirement. Material offered against the national table and accepted against a provincial one is the quiet route by which a technically compliant cargo becomes a rejected one.
8. 约定复检口径 · Agree the retest basis before anything moves
The zone decides which line will be marginal, and therefore which line the destination laboratory reaches for first. In a cold zone that is ductility at 10 °C and the residue ductility after ageing; in a hot zone it is the softening point and the 60 °C dynamic viscosity. Settle in the contract which laboratory performs any retest, which zone-dependent limit table the result is judged against, how a marginal result is resolved, and that sealed retained samples from the same batch are held by both parties. A retest argued after discharge, against a limit table that nobody named while the cargo was still on the water, is the most expensive possible way to discover that the zone code mattered.
常见问题 · Frequently asked questions about the climate zone code
气候分区代码怎么读？How is the JTG F40 climate zone code read?
It is three digits in a fixed order. The first is the summer high-temperature zone (夏季高温分区) from the mean maximum air temperature of the hottest month: 1 above 30 °C, 2 between 20 and 30 °C, 3 below 20 °C. The second is the winter low-temperature zone (冬季低温分区) from the extreme minimum air temperature: 1 below -37 °C, 2 from -37 to -21.5 °C, 3 from -21.5 to -9 °C, 4 above -9 °C. The third is the rainfall zone (雨量分区) from annual precipitation: 1 above 1000 mm, 2 from 500 to 1000 mm, 3 from 250 to 500 mm, 4 below 250 mm. The code is written as 1-4-1 or 2-2-2, and in every position the digit 1 marks the most demanding end of that variable.
1-4-1 和 2-2-2 分别是什么气候？What do 1-4-1 and 2-2-2 describe?
1-4-1 is hot summers with the hottest month averaging a daily maximum above 30 °C, mild winters with an extreme minimum above -9 °C, and heavy rainfall above 1000 mm a year. The binder problem there is rutting, with moisture damage running alongside it. 2-2-2 is warm summers between 20 and 30 °C, severe winters with an extreme minimum between -37 and -21.5 °C, and moderate rainfall between 500 and 1000 mm. The binder problem there is thermal cracking, and the grade selection moves in the opposite direction — softer, not harder.
冬季分区为什么数字小反而更冷？Why does a lower winter digit mean a colder winter?
Because the divisions run from severe to benign rather than from cold to hot, and this holds in all three positions of the code. A second digit of 1 is the coldest division in the system, below -37 °C; a second digit of 4 is the mildest, above -9 °C. The same convention applies to the first digit, where 1 is the hottest summer, and to the third, where 1 is the wettest climate. Reading the winter digit backwards is one of the most common errors, and it inverts the grade selection entirely.
分区代码能直接决定用哪个标号吗？Does the zone code decide the grade on its own?
No. It narrows the answer, and it is one of four inputs. The other three are the traffic loading — heavy, slow, channelised traffic is what actually turns a hot summer into a rut — the pavement layer, since surface, intermediate, lower and base layers see different temperatures and different stresses and a single project routinely specifies different grades in different layers, and the mix type, because a dense-graded wearing course, a stone-matrix mix and an asphalt-treated base do not ask the same thing of the binder. The binding selection is made by the design and stated in the project documents. A supplier establishes which grade and class have been selected and then proves the binder against them.
夏天很热、冬天又极冷的地区怎么选号？What if a site is both hot in summer and severe in winter?
That combination is where an unmodified binder runs out of range, and it should be recognised early rather than negotiated late. A conventional penetration-graded binder has one adjustable property — consistency — and moving it along the series improves one end at the expense of the other. Choosing a harder grade to resist summer rutting makes the binder more brittle in winter; choosing a softer grade to survive the winter makes it rut in summer. A modified binder (改性沥青) widens the useful temperature interval instead of sliding it along, which is why JTG F40 carries requirement tables for modified binder in the same materials chapter. This is a technical limit, not a sales position.
气候分区和PG等级是一回事吗？Is the climate zone code the same idea as a PG grade?
No, and the difference is structural. The JTG F40 divisions are defined on air temperature statistics measured at a meteorological station. A performance grade such as PG 64-22 is defined on pavement temperature and is established by running a dynamic shear rheometer and a bending beam rheometer on that specific binder. A zone code therefore cannot be converted arithmetically into a PG grade, because the pavement is hotter than the air in summer and the relationship depends on depth, surface colour, wind and solar radiation. Equally, a PG certificate does not discharge a JTG F40 requirement, since it reports none of the properties JTG F40 tests. Where both appear in one tender, they are satisfied separately on their own test data.
雨量分区会影响沥青采购吗？Does the rainfall digit affect the binder purchase?
It does not change the grade, but it changes what has to be proved. A humid third digit means moisture damage and stripping are the leading durability risk, which drives adhesion provisions, anti-stripping treatment, drainage design and water sensitivity testing at mixture level. The point for a supplier is that binder–aggregate adhesion is a property of the pair rather than of the binder alone, so it has to be established by testing the binder against the project’s actual aggregate. No penetration or softening point value predicts it, and a general claim of good adhesion made without knowing the aggregate has not been measured by anyone.
供应商怎么拿到项目的分区代码？How does a supplier obtain the project’s zone code?
By asking the buyer for it, and by asking for the project specification document rather than only the grade name. The code appears in the design and tender documents because it belongs to the project location, and it matters beyond selection: the ductility limit at 10 °C and the residue ductility limits after ageing are tabulated against quality class and climate zone, so a certificate of analysis issued without the zone is incomplete on exactly the lines a cold-region project will retest first. If the buyer cannot supply it, that is a signal to slow the enquiry down rather than to guess a code from a city name.
按气候分区询价 · Request a quotation against your climate zone
Send the project’s climate zone code, the grade (标号) and quality class the design has selected, the pavement layer, quantity, packing, destination port and Incoterm. If the code shows a severe division at both temperature ends, say so in the enquiry — that is a modified binder question and it is cheaper to settle before an offer is built than after one is priced. Where the project specification or a provincial technical document is available, attach it and the offer will be checked against the zone-dependent limits line by line.