专业英语18-21 高频词汇

Unit 18 Portland Cement

Portland cement is made by heating a mixture of limestone and clay, or other materials of similar bulk composition and sufficient reactivity, ultimately to a temperature of about 1450℃.

波特兰水泥是通过煅烧石灰石和粘土或其他大体相似结构的材料并进行充分反应，直到温度达到1450℃时制成的。

Partial fusion occurs, and nodules of clinker are produced.

部分融合发生了,并且熟料的结块也产生了。

The clinker is mixed with a few per cent of calcium sulfate and finely ground, to make the cement.

熟料与少量的硫酸钙混合，然后磨细，用来制水泥。

The calcium sulfate controls the rate of set and influences the rate if strength development .

硫酸钙控制凝结的时间并且影响强度的发展。

It is commonly described as gypsum, but this may be partly or wholly replaced by other forms of calcium sulfate.

它通常被描述为石膏,但是石膏可能是部分或全部被其他形式的硫酸钙取代。

Some specifications allow the addition of other materials at the grinding stage.

许多规范允许加入处于粉末阶段的其他材料的外加剂。

The clinker typically has the addition in the region of 67% CaO, 22%SiO2, 5%Al2O3, 3% Fe2O3 and 3% other components, and normally contains four major phases, called

alite ,belite ,aluminate and ferrite .

典型的熟料加入配比是67%的氧化钙,22%的二氧化硅, 5%的氧化铝，3%的氧化铁和3%其他的组分范围,通常包含四个主要相,称为阿利特、贝利特、铝酸盐、铁氧体等。

Several other phases, such as alkali sulfates and calcium oxide are normally present in minor amounts .

其他几种相，例如碱式硫酸盐和氧化钙，以极少数量存在。

Hardening results from reactions between the major phases and water.

硬化是由主要相和水反应的结果。

Alite is the most important constituent of all normal Portland cement clinker , of which it constitutes 50%-70%.

阿利特是所有普通波特兰水泥熟料的最重要的组成部分,它的含量为50% - -70%。

It is tricalcium silicate modified in composition and crystal structure by ionic substitutions.

硅酸三钙的组成和晶体结构通过离子交换。

It reacts relatively quickly with water ,and in normal Portland cements is the most important of the constituent phases for strength development; at ages up to 28 days , it is by far the most important.

它与水的反应相对快速,并且在普通波特兰水泥中对于强度发展来说是最重要的组成相,在龄期28天

时间内最重要。

Belite constitutes 15%-30%of normal Portland cement clinkers.

贝利特占普通波特兰水泥熟料构成的15% - -30%

It is dicalcium silicate modified by ionic substitution and normally present wholly or largely as the ß polymorph.

硅酸二钙通过离子交换形成并且全部或大部分以ß相存在。

It reacts slowly with water, thus contributing little to the strength during the first 28 days.

它与水反应缓慢,从而导致在第一个28天对强度几乎没有什么贡献。

But substantially to the further increase in strength that occurs at later ages.

但是对后期强度增长非常显著。

By one year, the stengths obtainable from pure alite and pur belite are about the same under comparable conditions.

经过一年，在可比的条件下，从纯的阿利特和纯的贝利特获得的强度是相同的。

Auminate constitutes 5%-10% of most normal Portland cement clinkers.

铝酸三钙占大部分普通波特兰水泥熟料的5% - -10% 。

It is tricalcium aluminate , substantially modified in composition and sometimes also in structure by ionic substitutions.

这是偏铝酸三钙, 在组分和结构上也是通过离子交换形成的。

It reacts rapidly with water , and cause undesirably rapid setting unless a setcontrolling agent, usually gypsum, is added.

它与水反应迅速,并且引起不希望得到的早凝，除非有凝结调节剂如石膏的加入。

Ferrite makes up 5%-15% of most normal Portland cement clinkers.

菲利特占普通波特兰水泥熟料的5%——15%。

It is tetracalcium aluminoferrite ,substantially modified in composition by variation in Al/Fe ratio and ionic substitutions.这是铁铝酸四钙，组分上通过变化铝与铁的比例和离子交

换形成。

The rate at which it reacts with water appears to be somewhat variable ,perhaps due to differences in composition or other characteristics,but in general is high initially and low or very low at later ages.

它与水反应的速率看起来稍微有点儿变化，可能由于在组分和其他特性的不同，但总体上初期高，后

The great majority of Portland cement made throughout the world are designed for general constructional use.

整个世界的一般建筑都使用的是普通水泥。

The standard specifications with which such cements must comply are similar, but not identical, in all countries and various names are used to define the material ,such as Class42.5 .

这种水泥的标准规范必须遵从相似但不完全一致，在所有国家以不同的名字定义材料,例如等级为42.5的普通谁您。

Portland cement in current European and British standards (42.5 is the minimum28-days compressive strength in MPa ), type I and II Portland cement in the ASTM (American Society for Testing and Materials ) specifications used in the USA , or Ordinary Portland Cement (OPC) in former British standards .

在当今欧洲和英国标准叫等级为42.5的普通水泥，在美国ASTM标准定义I型和 II型普通水泥，或在先前的英国标准中成为普通波特兰水泥。

Throughout this book , the term “ordinary” Portland cement is used to distinguish such general-purpose cements from other types of Portland cement , which are made in smaller quantities for special purpose.

在这本书里，普通波特兰水泥用来区别例如特种水泥的其他波特兰水泥，它们是为特殊目的而少量生