Author: Haroon Khalil

Different steel sections are used to form trusses, beams and columns. Individual steel sections or built-up sections are used.

In order to make steel structures, for example, beams and columns, the standard sections are combined in a suitable way. Such a combined section is called a built-up section. Figure 24.2 shows built-up sections composed of I-sections only. Likewise Fig. 24.3 shows built-up sections formed by combining I-section and plates. Figure 24.2 Built-up sections formed by…

There are two principal forms of welding of steel, viz., electric arc welding and oxyacetylene gas welding. The electrical welding is further divided into resistance arc, shielded arc and atomic hydrogen welding. In both the types of welding, the members to be welded are placed in contact and edges are melted so that the metal…

Bolt joints are used for temporary connections. For bold joints, the diameter of the hole is kept 1 mm larger than the external diameter of the bolt threads. In difficult situations, such as lesser number of rivets or difficulty in connecting, bolt connections are resorted to.

Members are connected by rivet which can not be removed unless the rivet is destroyed. Rivets are either fitted at site or in the fabrication shop. The former is called field rivets and the latter as shop rivets. Rivets used in building construction are of soft steel with a tensile strength of the order of…

Steel members are fastened together by means of rivets, bolts or by welding. Among the three approaches welding has been used in most of the works as they have large advantages.

These are the new type bars produced from the ribbed TOR steel which is a deformed high strength steel. These bars have ribs or projection on their surface. The ribbed TOR steel bars are available in sizes varying from 6 to 50 mm diameter. These bars are largely used as reinforcement in concrete structures. These…

Plain or ribbed steel sheets are cut and expanded to form expanded metal. These are used in ferro-cement concrete works. Welded fabric with ribbed mesh has a rectangular or square mesh is another form of mesh used in construction (Fig. 24.1(e)).

These sections are named based on their shapes (Fig. 24.1(c) and (d)). I-section is usually referred to as rolled steel joist (RSJ) or beam. RSJs are used for floor beams, lintels, columns, etc. T-sections are used in steel roof trusses, in built-up sections, in steel water tanks and in chimneys and bridges. The economic use…

It has two equal flanges and a web (Fig. 24.1(b)). A channel section is designated by the height of web and the width of flange and they are available in different sizes. These are used in steel framed structures, girders and steel bridges. Figure 24.1 Commercial sections of steel