Classification of reinforcement

钢筋由于品种、规格、型号的不同和在构件中所起的作用不同，在施工中常常有不同的叫法。对一个钢筋工来说，只有熟悉钢筋的分类，才能比较清楚地了解钢筋的性能和在构件中所起的作用，在钢筋加工和安装过程中不致发生差错。

Due to the variety, specification and model of steel bars and their different functions in members, there are often different names in construction. For a steel worker, only if he is familiar with the classification of steel bars, can he clearly understand the performance of steel bars and the role they play in the components, and will not make mistakes in the process of steel bar processing and installation.

钢筋的分类方法很多，大致如下。一、按钢筋在构件中的作用

There are many classification methods of steel bars, roughly as follows. 1、 According to the role of reinforcement in components

1、受力筋：是指构件中根据计算确定的主要钢筋，包括有：受拉筋、弯起筋、受压筋等。

1. Stress bar: refers to the main reinforcement determined according to the calculation in the component, including: tension bar, bending bar, compression bar, etc.

2、构造钢筋：是指构件中根据构造要求设置的钢筋，包括有：分布筋、箍筋、架立筋、横筋、腰筋等。

2. Structural reinforcement: refers to the reinforcement set in the component according to the structural requirements, including: distribution reinforcement, stirrup, erection reinforcement, transverse reinforcement, waist reinforcement, etc.

二、按钢筋的外形

2、 According to the shape of reinforcement

1、光圆钢筋：钢筋表面光滑无纹路，主要用于分布筋、箍筋、墙板钢筋等。直径6-10mm时一般做成盘圆，直径12mm以上为直条。

1. Plain round steel bar: the surface of the steel bar is smooth and without lines, mainly used for distributing steel bar, stirrup, wall board steel bar, etc. When the diameter is 6-10 mm, it is generally made into a circle, and the diameter of more than 12 mm is a straight bar.

2、变形钢筋：钢筋表面刻有不同的纹路，增强了钢筋与混凝土的粘结力，主要用于柱、梁等构件中的受力筋。变形钢筋的出厂长度有9m、12m两种规格。

2. Deformed steel bar: the surface of the steel bar is engraved with different lines, which enhances the bond between the steel bar and the concrete. It is mainly used for the stress bars in columns, beams and other components. The factory length of deformed steel bars is 9m and 12m.

3、钢丝：分冷拔低碳钢丝和碳素高强钢丝两种，直径均在5mm以下。

3. Steel wire: it is divided into cold drawn low carbon steel wire and carbon high-strength steel wire, with diameter less than 5mm.

4、钢绞线：有3股和7股两种，常用于预应力钢筋混凝土构件中。

4. Steel strand: there are three strands and seven strands, which are commonly used in prestressed reinforced concrete members.

三、按钢筋的强度

3、 According to the strength of reinforcement

在钢筋混凝土结构中常用的是热轧钢筋，热轧钢筋按强度可分为四级，HPB235（Ⅰ级钢），其屈服强度标准值为235MPa；HRB335（Ⅱ级钢），其屈服强度标准值为335MPa；HRB400（Ⅲ级钢），其屈服强度标准值为400MPa；RRB400（Ⅳ级钢），其屈服强度标准值为400MPa。现浇楼板的钢筋和梁柱的箍筋多采用HPB235级钢筋；梁柱的受力钢筋多采用HRB335、HRB400、RRB400级钢筋。

Hot rolled steel bars are commonly used in reinforced concrete structures. Hot rolled steel bars can be divided into four grades according to their strength. Hpb235 (grade I steel) has a standard value of yield strength of 235mpa; HRB335 (grade II steel) has a standard value of yield strength of 335mpa; HRB400 (grade III steel) has a standard value of yield strength of 400MPa; rrb400 (grade IV steel) has a standard value of yield strength of 400MPa. Hpb235 steel bars are mostly used for the reinforcement of cast-in-place floor slab and stirrup of beam column; HRB335, HRB400 and rrb400 steel bars are mostly used for the stress reinforcement of beam column.