Wall Tie System

Wall Tie System is a complete set of matched formwork fastening hardware widely used in cast‑in‑place concrete wall construction. The system mainly includes wall tie rods, fastening nuts, pressure bearing plates, positioning cones, plastic sleeves and water‑stop plates for waterproof projects. Each component undertakes independent mechanical functions. All accessories work together with formwork panels to realize formwork tensioning, wall‑thickness positioning and water‑sealing performance without altering main formwork structures. High‑strength carbon steel is adopted as primary raw material. According to working conditions, the system is classified into ordinary wall tie system and waterproof wall tie system. Ordinary type is applied for general non‑waterproof wall structures. Waterproof version is equipped with fully‑welded water‑stop plate on the middle embedded rod to block water penetration paths along rod penetration positions. Two main structural types are integral one‑piece type and segmented assembled type. Integral wall tie rod runs through the whole wall thickness and is permanently embedded in concrete for single‑time use. Assembled wall tie consists of embedded middle section and detachable outer threaded segments, and outer threaded parts can be unscrewed and reused after concrete curing. Thread sections are processed by thread rolling technology to improve thread‑tooth hardness and wear resistance for frequent assembly, disassembly and cyclic turnover. Fastening nuts are produced by forging craft to guarantee stable clamping force under lateral hydrostatic pressure from fresh concrete. Welding quality of water‑stop plates shall be strictly controlled to ensure anti‑seepage performance for basement, water tank and hydraulic‑engineering structures. Positioning cones and plastic sleeves precisely control wall‑thickness dimension and reduce later surface repair work of concrete walls. Custom dimensions can be manufactured according to project drawing requirements.

Multiple surface anti‑corrosion treatments are available for metal components of wall tie system. Hot‑dip galvanizing forms compact zinc‑iron alloy protective layers covering rod bodies, thread sections and welding seams. This treatment provides stable resistance against rainwater, humid air and salt‑fog erosion, suitable for long‑term outdoor, coastal and underground construction projects. Electro‑galvanizing forms thin zinc coating on steel surface, suitable for short‑cycle construction projects with low corrosion risk. Black oxide finish fits temporary dry‑condition construction sites without strict anti‑corrosion requirements. Paint coating is rarely used on threaded parts, as paint layers tend to peel off under thread friction and concrete impact. Wall tie system bears lateral expanding force generated during concrete pouring, fixes spacing between opposite formwork panels, restrains formwork bulging, shifting and deformation, and ensures dimensional stability of cast‑in‑place concrete wall components.

Core dimensional parameters determine practical mechanical performance of the whole system. Rod body diameter is a critical tensile‑load indicator, larger diameter corresponds to higher ultimate tensile capacity. Effective total length shall match designed wall thickness, formwork panel thickness and on‑site operating space. Thread specifications of tie rods and nuts must keep fully consistent to avoid poor meshing, insufficient clamping force and component slipping. For waterproof‑type assemblies, dimension and welding quality of water‑stop plates shall satisfy anti‑seepage requirements under designed water head. Specification mismatch of positioning accessories will result in concrete dimension deviation. This system is widely compatible with timber formwork, steel formwork and various combined formwork assemblies. Dimensional tolerances of all components comply with corresponding international technical specifications to guarantee reliable fitting and stable force transmission during on‑site assembly.

Prior to construction deployment, visual inspection and sampling mechanical tests shall be carried out for wall tie system. Visual examination covers rod‑body bending deformation, surface cracks, welding discontinuity, thread‑tooth damage and anti‑corrosion‑layer peeling. Recycled outer threaded segments require stricter inspection standards. Even with intact outward appearance, invisible metal fatigue may accumulate after repeated load cycles and cannot be judged merely through surface observation. Sampling tensile tests verify ultimate bearing capacity and anti‑deformation performance. Components with permanent bending, thread slipping, incomplete welding and structural cracks must be screened out and prohibited for site usage. Secondary destructive modification including arbitrary cutting, welding and hole‑drilling on finished system components is forbidden. Unauthorized alteration will change original steel section characteristics and weaken tensile performance or waterproof reliability of the whole assembly.

Part of components in wall tie system support cyclic turnover usage. After concrete reaches design strength and formwork dismantling, detachable outer threaded segments, reusable nuts and pressure‑bearing accessories shall be disassembled following standard construction sequence. Concrete mortar, dust and foreign residues attached to thread grooves and fitting surfaces need thorough cleaning before next application. Impurities trapped in matching joints will cause jamming and interfere with normal assembling and clamping effect in subsequent service cycles. Finished components shall be stored in dry and ventilated surroundings, sorted and stacked by specification grade, avoiding long‑term rain soaking and direct contact with damp soil. Improper on‑site operations include mixed use of mismatched accessories, insufficient tightening of nuts, adoption of damaged parts and applying load exceeding rated capacity. These misoperations may trigger formwork bulging, component fracture, concrete dimension deviation or wall‑body water seepage risks. As a key penetrating fastening solution for concrete formwork engineering, raw‑material quality, processing craftsmanship, component‑matching accuracy and welding performance of wall tie system directly determine construction safety, concrete forming quality and long‑term anti‑leakage performance of wall structures, and constitute essential preconditions for cast‑in‑place concrete wall construction.