2024年3月25日发(作者：奈映秋)
13
Properties of Fresh Concrete
新拌混凝土的性能
Fresh concrete is a mixture of water, cement, aggregate and admixture (if any). After
新拌混凝土为水、水泥、集料和外加剂（如果
mixing, operations such as transporting, placing, compacting and finishing of fresh concrete
有的话）的混合物。搅拌后，新拌混凝土的操作如
can all considerably affect the properties of hardened concrete. It is important that the
输送、浇注、密实和终饰也会显著影响硬化混凝土
constituent materials remain uniformly distributed within the concrete mass during the various
的性能。组成材料在施工的不同时期保持在混凝土
stages of its handling and that full compaction is achieved. When either of these conditions is
中的均匀分布及完全密实是很重要的。若这些条件
not satisfied the properties of the resulting hardened concrete, for example, strength and
不理想，成品硬化混凝土的性能如强度和耐久性就
durability, are adversely affected.
有不利影响。
The characteristics of fresh concrete which affect full compaction are its consistency,
新拌混凝土影响完全密实的特性是其稠度、流
mobility and compactability. In concrete practice these are often collectively known as
动性和密实性。在混凝土实践中这些一起被称为和
workability. The ability of concrete to maintain its uniformity is governed by its stability,
易性。混凝土维持其均匀性的能力由其稳定性控制，
which depends on its consistency and its cohesiveness. Since the methods employed for
稳定性又取决于稠度和粘聚性。由于对混凝土拌和
conveying, placing and consolidating a concrete mix, as well as the nature of the section to be
物运输、浇注和捣固采用的方法与浇注构件的性质
cast, may vary from job to job it follows that the corresponding workability and stability
一样随工程不同而异，因此相应的和易性和稳定性
requirements will also vary. The assessment of the suitability of a fresh concrete for a
要求也会改变。对特定工作新拌混凝土的适应性的
particular job will always to some extent remain a matter of personal judgment.
评定在某种程度上总存在人为判断的问题。
In spite of its importance, the behaviour of plastic concrete often tends to be overlooked.
尽管很重要，但塑性混凝土的行为通常被忽视。
It is recommended that students should learn to appreciate the significance of the various
建议学生应学会鉴定塑性状态混凝土的不同特性的
characteristics of concrete in its plastic state and know how these may alter during operations
重要性，了解在包括浇注混凝土结构的施工操作时
involved in casting a concrete structure.
如何去改变它们。
13—1
13.1 Workability
和易性
Workability of concrete has never been precisely defined. For practical purposes it
混凝土的和易性从未被准确定义。实践时一般
generally implies the ease with which a concrete mix can be handled from the mixer to its
认为是指混凝土拌和物从搅拌机施工到其最终密实
finally compacted shape. The three main characteristics of the property are consistency,
形状的容易程度。和易性的三个主要特性是稠度、
mobility and compactability. Consistency is a measure of wetness or fluidity. Mobility defines
流动性和密实性。稠度指湿润度或流度的度量。流
the ease with which a mix can flow into and completely fill the formwork or mould.
动性指拌和物流进并完全充满模板或模具的容易程
Compactability is the ease with which a given mix can be fully compacted, all the trapped air
度。密实性指给定拌和物完全密实，排除所有截留
being removed. In this context the required workability of a mix depends not only on the
空气的容易程度。本章要求的拌和物和易性不仅取
characteristics and relative proportions of the constituent materials but also on (1) the methods
决于组成材料的特性和相应比例，而且取决于（1）
employed for conveyance and compaction, (2) the size, shape and surface roughness of
运输和密实采用的方法，（2）模板或模具的尺寸、
formwork or moulds and (3) the quantity and spacing of reinforcement.
形状和表面粗糙度，（3）钢筋的数量和间距（布筋）。
Another commonly accepted definition of workability is related to the amount of useful
另一个普遍接受和易性的定义指产生完全密实
internal work necessary to produce full compaction. It should be appreciated that the necessary
所必须的有用内功的数量。应认识到必需功又取决
work again depends on the nature of the section being cast. Measurement of internal work
于被浇注构件的性质。内功的确定存在许多困难，
presents many difficulties and several methods have been developed for this purpose but none
为此已发展了几种方法，但没有一种能给出和易性
gives an absolute measure of workability.
的绝对确定。
The tests commonly used for measuring workability do not measure the individual
通常用于确定和易性的实验不能确定和易性的
characteristics (consistency, mobility and compactability) of workability. However, they do
单一特性（稠度、流动性和密实性）。然而它们的确
provide useful and practical guidance on the workability of a mix. Workability affects the
给出了拌和物和易性的一个有用、实际的指导。和
quality of concrete and has a direct bearing on cost so that, for example, an unworkable
易性影响混凝土的质量，并直接影响成本，如和易
concrete mix requires more time and labour for full compaction. It is most important that a
性不好的混凝土拌和物完全密实要求更多时间和劳
realistic assessment is made of the workability required for given site conditions before any
力。最重要的是在对适宜的混凝土配比下任何结论
13—2
2024年3月25日发(作者：奈映秋)
13
Properties of Fresh Concrete
新拌混凝土的性能
Fresh concrete is a mixture of water, cement, aggregate and admixture (if any). After
新拌混凝土为水、水泥、集料和外加剂（如果
mixing, operations such as transporting, placing, compacting and finishing of fresh concrete
有的话）的混合物。搅拌后，新拌混凝土的操作如
can all considerably affect the properties of hardened concrete. It is important that the
输送、浇注、密实和终饰也会显著影响硬化混凝土
constituent materials remain uniformly distributed within the concrete mass during the various
的性能。组成材料在施工的不同时期保持在混凝土
stages of its handling and that full compaction is achieved. When either of these conditions is
中的均匀分布及完全密实是很重要的。若这些条件
not satisfied the properties of the resulting hardened concrete, for example, strength and
不理想，成品硬化混凝土的性能如强度和耐久性就
durability, are adversely affected.
有不利影响。
The characteristics of fresh concrete which affect full compaction are its consistency,
新拌混凝土影响完全密实的特性是其稠度、流
mobility and compactability. In concrete practice these are often collectively known as
动性和密实性。在混凝土实践中这些一起被称为和
workability. The ability of concrete to maintain its uniformity is governed by its stability,
易性。混凝土维持其均匀性的能力由其稳定性控制，
which depends on its consistency and its cohesiveness. Since the methods employed for
稳定性又取决于稠度和粘聚性。由于对混凝土拌和
conveying, placing and consolidating a concrete mix, as well as the nature of the section to be
物运输、浇注和捣固采用的方法与浇注构件的性质
cast, may vary from job to job it follows that the corresponding workability and stability
一样随工程不同而异，因此相应的和易性和稳定性
requirements will also vary. The assessment of the suitability of a fresh concrete for a
要求也会改变。对特定工作新拌混凝土的适应性的
particular job will always to some extent remain a matter of personal judgment.
评定在某种程度上总存在人为判断的问题。
In spite of its importance, the behaviour of plastic concrete often tends to be overlooked.
尽管很重要，但塑性混凝土的行为通常被忽视。
It is recommended that students should learn to appreciate the significance of the various
建议学生应学会鉴定塑性状态混凝土的不同特性的
characteristics of concrete in its plastic state and know how these may alter during operations
重要性，了解在包括浇注混凝土结构的施工操作时
involved in casting a concrete structure.
如何去改变它们。
13—1
13.1 Workability
和易性
Workability of concrete has never been precisely defined. For practical purposes it
混凝土的和易性从未被准确定义。实践时一般
generally implies the ease with which a concrete mix can be handled from the mixer to its
认为是指混凝土拌和物从搅拌机施工到其最终密实
finally compacted shape. The three main characteristics of the property are consistency,
形状的容易程度。和易性的三个主要特性是稠度、
mobility and compactability. Consistency is a measure of wetness or fluidity. Mobility defines
流动性和密实性。稠度指湿润度或流度的度量。流
the ease with which a mix can flow into and completely fill the formwork or mould.
动性指拌和物流进并完全充满模板或模具的容易程
Compactability is the ease with which a given mix can be fully compacted, all the trapped air
度。密实性指给定拌和物完全密实，排除所有截留
being removed. In this context the required workability of a mix depends not only on the
空气的容易程度。本章要求的拌和物和易性不仅取
characteristics and relative proportions of the constituent materials but also on (1) the methods
决于组成材料的特性和相应比例，而且取决于（1）
employed for conveyance and compaction, (2) the size, shape and surface roughness of
运输和密实采用的方法，（2）模板或模具的尺寸、
formwork or moulds and (3) the quantity and spacing of reinforcement.
形状和表面粗糙度，（3）钢筋的数量和间距（布筋）。
Another commonly accepted definition of workability is related to the amount of useful
另一个普遍接受和易性的定义指产生完全密实
internal work necessary to produce full compaction. It should be appreciated that the necessary
所必须的有用内功的数量。应认识到必需功又取决
work again depends on the nature of the section being cast. Measurement of internal work
于被浇注构件的性质。内功的确定存在许多困难，
presents many difficulties and several methods have been developed for this purpose but none
为此已发展了几种方法，但没有一种能给出和易性
gives an absolute measure of workability.
的绝对确定。
The tests commonly used for measuring workability do not measure the individual
通常用于确定和易性的实验不能确定和易性的
characteristics (consistency, mobility and compactability) of workability. However, they do
单一特性（稠度、流动性和密实性）。然而它们的确
provide useful and practical guidance on the workability of a mix. Workability affects the
给出了拌和物和易性的一个有用、实际的指导。和
quality of concrete and has a direct bearing on cost so that, for example, an unworkable
易性影响混凝土的质量，并直接影响成本，如和易
concrete mix requires more time and labour for full compaction. It is most important that a
性不好的混凝土拌和物完全密实要求更多时间和劳
realistic assessment is made of the workability required for given site conditions before any
力。最重要的是在对适宜的混凝土配比下任何结论
13—2