Steel Reinforcement, Welding Standards, and Material Quality Control

Reinforcement Bars and Wires

Reinforcement bars and wire sizes (in mm):

• Bars (Corrugated, Smooth, and 40 Soldiers): 6, 8, 10, 12, 14, 16, 20, 25, 32.
• Wires (Smooth, used only for joists): 5, 6, 7, 8, 9, 10, and 12.

Material Properties and Identification

Key properties include: B lim elast. (Elastic Limit), Weldability, and Ductility. Features for identification include ovalization, the corrugation material identification, and country of origin.

Electrically Welded Mesh and High-Strength Steels

Electrically Welded Mesh (ME): Used for savings and separation (longitudinal x transverse). Identification includes: dl-disc (discontinuous longitudinal), BNS (bar), T (wire), b (width), xl (length), and electron beam processing (AB haltura c (step)).

The longitudinal superior element (Dc No Alamba) and the smooth element (OL) are specified. High-strength steels are used for the longitudinal active steel arm (UNE standard). Wire coils consist of 237 bars or tendon sheaths (parallel reinforcement units).

Quality Control and Certification

Control involves designating the starting material in a supply. Determination of reduced level sections (equivalent to normal sections) requires 2x batch certificates. For example, 40 tons (forces) versus 29 tons not certified.

Geometric and Elastic Limits

Certification is required for sections 20 and 10 (dd geometric limits, elastic equation). Weldability testing includes butt tensile strength (6xO) with overlapping (dd for 3 to Traction).

Steel Applications and Grades

Applications are categorized by tenacity (A 37, 42, or 52). Percentage additions are controlled: no base alloy (without precautions) is used in standard quality. Special alloys are of the purest quality (without impurities, temper resistant).

Unalloyed Structural Steels (European Standards)

European (E) structural steels (N) are graded based on impact resistance (Joule limits):

• JR, J0, J2 Grade for $n = 275$
• K2 Grade for $n = 405$

Subgrade Treatment Classification:

1. G1: Permitted without treatment.
2. G2: Treatment not allowed.
3. G3: Normalized, calm (to choose).
4. G4: Figures.

Structural Profiles and Shapes

Common structural shapes include:

• IPN-E and HE (Normal to High, Light, Heavy)
• UPN (Medium thickness, decreasing)
• L, LD (Rectangular side shows only the modified M)
• Conformed, soulless, cold-formed hollow profiles (O # LF sq. rect ZF LDF OF UF CF - specified by side and thickness)

EA-95 Standards, Joints, and Welding

Mechanical Joints (Screws and Rivets)

EA-95 Control requires hardness testing for each 20-ton class, ensuring resistance to the profile. Screw joints and rivets (Ocañaxlong EBP, TR, T, TC) are calibrated high-resistance components, distinguished by different sizes for coupling.

Welding Processes and Quality

Welding focuses on speed and simplification, reducing labor weight. Quality control includes autogenous gas resistance testing. Butt joints must contribute fully; every angle must be filled without residual material (Reller).

The filler metal electrode should be better than the original base material. Proper edge preparation is essential. Considerations include brittle fracture temperature (Tº) and pre-defects.

Welding Recommendations:

It is recommended to weld materials with less than 0.6% carbon content to decrease internal tensions. Freedom and symmetry in the workshop are crucial.

Welding Defects and Non-Destructive Testing (NDT)

Common defects include lack of penetration, craters, decreased section, surface scum, cracks, throat bites, and edge bites. Control methods include:

• Visual and Tactile Control
• Traction (DD Destructive)
• Hardness Testing (Non-destructive unless specified)
• Ultrasonic Testing
• Macrographic Dyes
• X and Gamma Rays

Non-Ferrous Metals

Aluminum (Al-Si-Mg)

Non-ferrous aluminum alloys (Al-Si-Mg) are weldable and corrosion resistant. Workability is key. Protection is provided by anodized oxide (bohemite), which acts as a porous insulator. Thickness control of the anode is necessary to prevent corrosion.

Other non-ferrous metals include copper and zinc.