Steel structure construction encompasses all production activities during the engineering implementation phase, involving the building process of various structures and their construction sites. Techniques and methods for steel structure construction have evolved significantly. Below, we present the latest innovations and approaches:
Masonry Walls Construction Without Scaffold Holes
Method: Begin by welding a T-shaped flat iron at the end of the scaffold’s steel pipe crossbar. The masonry height should align with the erection point, preferably at the intersection of vertical and horizontal mortar joints. When supporting the scaffold, place the T-shaped flat iron flat against the wall; mortar can be omitted at this point to facilitate easy assembly and disassembly.
Innovative Column and Ring Beam Construction Without Eye Formwork Supports
Process 1:
This method utilizes pre-embedded Φ14 tension bolts enclosed in Φ15 PVC plastic pipes within the “GZ” formwork sections to secure the formwork. This eliminates the need for frame holes in the masonry, enhancing the overall quality of the wall.
Specifics: The “GZ” formwork uses 12mm thick plywood reinforced with three 50mm × 80mm wooden ribs. Each side of the “GZ” uses a fixed template. During formwork support, tension bolts are pre-embedded in the “GZ” section. Four sets of 50mm × 80mm short wooden blocks lock each layer on the outer end, while 100mm × 100mm wooden blocks support the inner corners. This method suits “one”-shaped, L-shaped, and T-shaped brick concrete corners.
Process 2:
(1) Use standardized steel formwork combined with short steel pipes and specially designed through-wall bolts. These bolts consist of a Φ12 steel bar welded with a steel pipe sleeve or straight stopper on one end, and threaded on the other.
(2) Pre-embed plastic pipes at frame holes during wall construction. After completion, remove the plastic pipes to create reserved holes.
(3) When supporting the mold, insert a specially made Φ12 bolt into the reserved hole and tighten it with a nut.
Process 3:
Supporting Ring Beam Hard Frame Formwork:
(1) Embed a Φ16 PVC plastic pipe under the ring beam bricks during wall construction. After the wall is complete, gently twist and remove the pipe to form Φ16 installation holes spaced 800-1000mm apart.
(2) Attach a special tool made from ∟40 × 4 angle steel, securing it with a Φ14 bolt inserted into the installation hole.
(3) Install composite steel formwork, tighten bolts, and adjust for flatness.
Column Formwork Construction Process:
(1) During masonry, leave Φ16mm installation holes at 240mm horizontal mortar joint distance from structural columns, with vertical spacing no greater than 800mm, using Φ16 PVC plastic pipes.
(2) After reinforcing bars pass inspection, install composite formwork.
(3) Attach a special mold made from ∟50 × 5 angle steel and secure it with Φ14 through-wall bolts.
Process 4:
Cut PVC pipes to wall thickness and fit rubber plugs on both ends, matching the concrete cross-sectional dimensions. Use tension bolts to fix the formwork. After concrete curing and formwork removal, remove plugs and fill holes with 1:2 cement mortar for a smooth finish. Alternatively, use a 5mm thick flat iron with a 5cm 90-degree hook to insert into brick joints, providing equivalent wall support.
Advantages:
- Eyeless support molds reduce the number of shaping molds, increase mold turnover, lower costs, and simplify installation/removal.
- Leaving no holes in masonry enhances wall strength.
- Concrete surfaces are flat, smooth, and uniform in color, eliminating common issues like slurry stains and wall contamination.
- Eliminates the traditional eye lifting process, reducing labor costs and shortening construction timelines.
Fixed Formwork Applications for Frame Beam, Column, and Slab Joints
Method 1: Use a combination of small steel formwork and irregular angle formwork to support beam, column, and slab joints. Sponge strips are placed at formwork joints, with custom irregular corner templates tailored to specific conditions.
Method 2: Employ customized bamboo plywood templates for shaping.
Concrete Flanges in Bathrooms and Integral Floor Cast-in-Place Construction
To enhance bathroom waterproofing, suspend formwork and pour concrete flanges together with the floor as a single unit.
Use of Sponge Strips in Formwork Engineering
Before installing structural column and ring beam formwork in brick concrete structures, adhere soft or hard foam sponge strips with double-sided adhesive tape on both sides of the columns and walls below ring beams. This prevents wall contamination from concrete slurry overflow.
Inclined Top Brick Masonry on Infill Walls
Top bricks are pre-cut so their contacting surfaces are flat. When laid diagonally, they form a 60-degree angle with the horizontal plane.
Benefits: Flat upper and lower surfaces ensure mortar joints remain around 10mm thick, avoiding overly thick joints. The 60-degree incline enhances compactness and integration, preventing common issues such as seamless joint problems between plastered walls and frame beams. This method ensures neat masonry with excellent visual quality.
Cutting and Prefabrication of Irregular Bricks
Seven-quarter head bricks are prefabricated in the brick yard or cut onsite with a toothless saw. Protruding bottom bricks of horse-toothed patterns are cut with a 45-degree slope.
Advantages: The sloped cuts facilitate concrete pouring and compaction, improving the wall’s appearance.
Use of Skin Number Poles in Masonry
Skin number poles are made from 3cm × 5cm wooden squares with adjustable bases. They are clearly marked to indicate gray joints, reinforcement positions, and wall structure changes, ensuring stable fixation.
Precast Concrete Blocks for Door and Window Frames
Traditional wooden bricks embedded in porous brick walls often lack firm fixation. Prefabricated concrete blocks matching the original wooden brick cross-section now replace wooden bricks, providing a stable base for fixing door and window frames.
Steel Bar Position Fixing in Structural Columns
A cross-shaped steel bar fixing frame is installed atop structural columns. This frame, combined with hoop reinforcement, secures steel bars inside the skeleton, maintaining proper spacing. The frame is spot welded from Φ8 or Φ10 steel bars and sized to fit the column. It is fixed adjacent to both the brick wall and formwork, tied with hoop reinforcement before formwork installation, preventing displacement during pouring and vibration.
Anti-Pollution Measures for Steel Reinforcement
Before pouring concrete, place PVC pipes on column steel bars with pipe bases positioned at concrete pouring elevation. This prevents cement slurry from contaminating steel bars and facilitates concrete work.
Retaining Construction Joints in Stair Treads
When supporting stair formwork, construction joints should be positioned within one-third of the cast-in-place floor slab span. These joints cross the bottom formwork and include slots aligned with steel bar spacing. Steel bars must be clamped without displacement and perpendicular to the formwork, with pads ensuring proper protective layer thickness below main reinforcement.
Concrete Curing for Cast-in-Place Columns
After pouring, promptly implement curing measures as per technical plans. Cover and moisten concrete within 12 hours. Maintain moisture by watering with the same water used for mixing. Use plastic sheets to tightly cover cured surfaces, ensuring condensation forms beneath. When watering or plastic sheeting is infeasible, apply curing agents.
Stair Step Corner Protection
Stair tread dimensions are strictly followed per design. External corners are reinforced with full-length copper or plastic strips, angle steel, or 6mm steel bars. Protective strips are embedded within plaster layers for flush, consistent surfaces. Water-blocking brick edges and drip troughs are installed on the outer stair edges.
Floor Tile Cut and Slope at Drains
When tiling bathroom and kitchen floors, tiles around floor drains are cut diagonally into four sections and laid with slopes on all sides, creating smooth drainage surfaces. This improves visual appeal and prevents slope reversal and drainage issues common in traditional methods.
Embedding Plastic Strips on Kickboard Upper Openings
Steps:
(1) After leveling, clean and moisten the wall.
(2) Tile and grout the wall.
(3) Embed plastic strips using 1:2 cement mortar or plaster powder.
(4) Smooth corner lines.
(5) Continue subsequent construction.
Benefits: This method produces clear, color-separated inner corner lines, reducing contamination and eliminating issues with hidden corner lines and rough walls during later decoration.
Preventing Floor Tile Uplift
Before tiling, apply an 8-10mm thick polystyrene board around the wall to create an elastic interface between wall and floor. Use a 1:2 cement-fly ash mortar with 3-5mm joints for tile bonding.
Bonding and Roughening Indoor Wall Tile Base Layers
Use specialized plastering tools to create 3mm wide grooves or other roughening methods on the base layer to enhance adhesion, prevent tile hollowing, and improve overall durability.
Leak Prevention at Water Supply and Drainage Pipeline Roots
Prior to floor leveling in kitchens and bathrooms, pour fine stone concrete slopes around pipeline roots. Apply an additional waterproof layer extending 20mm below ground surface. Use plastic sleeves at PVC pipe bases with net heights of 20mm and diameters 25-40mm larger than pipe outer diameters. Fill pipes with water and sand mortar, smooth openings, and paint.
Advantages: This waterproofing method prevents common leakage at pipe roots and creates clean, tidy installations.
Hole Reservation and Blocking for Vertical Pipes at Different Water Levels
Process:
(1) Fabricate simple hole-blocking molds from iron plates.
(2) Use the riser as support and install the mold.
(3) Pour concrete into holes.
(4) Remove, clean, oil, and store the mold for reuse.
Benefits: Molds are easy to make, quick to install and remove, reusable, and prevent quality issues like blocked holes or uneven pipe roots.
Fixing Wooden Door Frames with Rear Plugs
Steps:
(1) After plastering, leave a 1.5-2mm gap around door/window openings to size wooden frames.
(2) Straighten, level, and temporarily fix wooden frame; drill Φ6 holes vertically along the frame at least 70mm deep.
(3) Cut Φ6.5 steel bars to 105mm, bevel one end, hammer into wall, embedding other end slightly into frame.
(4) Fill gaps with elastic material and seal with sealant.
Benefits: Saves wood bricks, improves installation firmness, ensures plaster flatness around frame, and protects the frame from plastering damage.
Techniques to Prevent Wall Cracks
Set 60mm thick horizontal and vertical cast-in-place reinforced concrete strips or reinforcement bars beneath window sills on first and top floors to prevent or reduce wall cracking.
Vacuum Water Absorption for Large-Area Concrete Pouring
After pouring, vibrating, and leveling concrete, place suction pads on the surface and operate vacuum equipment to extract free water.
Advantages: Accelerates construction, enhances concrete strength, and shortens project duration.
Raw Mortar Joint Scraping in Masonry
Replace traditional wall sweeping with joint scraping using raw mortar during masonry, streamlining the process.
Reinforcement of Concrete Shear Walls and Column Formwork
Use PVC pipes and plastic plugs with tension bolts to reinforce formwork, preventing slurry leakage during pouring and vibration. Screws are easily extracted, improving screw reuse. The plug creates a horned opening to facilitate bolt hole sealing.
Post-Tying Reinforcement Planting Method
Promote structural adhesive post-planting for tie bars at infill wall and frame column junctions, replacing traditional embedded iron and steel bars. This ensures accurate positioning and elevation of tie bars.
Gypsum Plastering Instead of Cement or Mixed Mortar
Application in Indoor Plastering:
Gypsum plastering involves a base layer and a surface layer. The base layer provides leveling (minimum thickness 5mm) and is applied similarly to cement mortar, using mechanical mixing, spraying, and manual finishing. The surface layer fills minor surface pits with a thin (1-2mm) steel-troweled coat for smoothness.
Advantages: Gypsum plastering offers early strength, rapid hardening, fire resistance, excellent bonding, humidity regulation, and a smooth, comfortable finish. It prevents common issues like hollowing, cracking, peeling, and detachment, and requires no special base preparation or interface agents.
Cold Drawn Chrome Plating for Stair Railings
Process: Steel bars, 4mm thicker than design size, are cold drawn down to design diameter and then chrome plated.
Advantages: This process improves railing smoothness, brightness, cleanliness, and rust resistance compared to traditional chrome plating of round steel.
External Corner Plastering Using Embedded L-Shaped Corner Strips
After plastering and leveling, apply L-shaped corner strips to corners, ensuring full or intermittent adhesion. Use corner bars to replace surface plaster at corners, smoothing sharp edges. When plastering, the strips can be directly embedded and covered.
Corner Strip Types:
1. Plastic strips for walls, columns, beams, doors, and windows.
2. Corner strips for ceramic tile walls.
Benefits:
– Produces straight, clear, and attractive corner lines.
– Simplifies construction and enhances quality control.
– Provides effective corner protection.
Wear-Resistant Copper Strips on Stair Treads
Apply wear-resistant copper strips on stair outer corners for durability, ease of installation, and aesthetic appeal.
Wooden Door Leaf Paint Scraping Process
Steps:
(1) Clean base surface.
(2) Remove grease.
(3) Apply and smooth putty.
(4) Polish flat.
(5) Paint.
(6) Apply putty again.
(7) Polish smooth.
(8) Paint and smooth.
(9) Fine sanding.
(10) Final paint and polish with a large board after drying.
Benefits: Achieves a smooth, glossy, consistent, and thick paint finish, eliminating brush marks and sagging.
Full Wire Suspension Rod Technology in Installation Engineering
Made from first-grade fully threaded and galvanized round steel. Cut onsite to length, then fitted with nuts, washers, expansion tubes, and internal expansion bolts to create self-expanding anchoring ends for suspension.
Advantages: Easy onsite operation, fast installation, and excellent post-installation appearance.
Groove Connection Technology for Hot Dip Galvanized Pipes
Utilizes high-quality rubber seals and corrosion-resistant ductile iron joints lasting longer than pipes. Flanges mesh with groove rings and are secured with high-strength bolts.
Advantages: Easy operation, quick installation, no need for secondary galvanizing or rust removal, convenient maintenance, and 10-20% cost savings over traditional methods.
Use of Centrifugal Cast Iron Pipes in Drainage
These pipes feature dense structure, thin walls, and light weight. Connections use stainless steel clamps and rubber rings for easy installation and removal. Compared to socket cast iron and PVC pipes, they offer easier maintenance, leak prevention, corrosion and aging resistance, noise reduction, and long service life.
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