What Are the Substrate Wall Requirements for Installing UHPC Exterior Wall Panels? Compatibility Standards and Treatment Solutions

The installation of UHPC exterior wall panels places core requirements on the substrate wall: "adequate strength, flatness and stability, and waterproofing compatibility". It must meet standards such as substrate strength ≥0.3MPa, flatness ≤3mm/m, and reliable stability. Through substrate inspection, targeted treatment, and precise installation, Qinglong achieved a 100% installation pass rate on projects such as Shenzhen Pingshan High-tech Zone and Hainan Poly Peninsula No. 1.

1. Core Substrate Requirements: Basic Compatibility Standards

The substrate must meet the following core conditions to guarantee installation quality. Strength requirement: the substrate wall must have a compressive strength ≥0.3MPa, and concrete substrate strength ≥C25; Qinglong tests with a rebound hammer and will not begin construction if strength fails to meet the standard. Flatness requirement: wall flatness deviation ≤3mm/m and verticality deviation ≤5mm per story; Qinglong tests with a laser rangefinder and levels any areas exceeding the limit. Stability requirement: the substrate must be free of cracks and hollowing, and structural settlement must be stable (settlement rate ≤0.01mm/d); Qinglong uses the tapping method for hollowing detection, and hollowed areas over 5% must be repaired. Waterproofing requirement: the substrate must be waterproofed (by applying waterproof coating or laying waterproof membrane); Qinglong installs only after the substrate waterproofing passes acceptance. Compatibility requirement: the substrate material must be compatible with UHPC panel hangers to avoid electrochemical corrosion; Qinglong installs anti-corrosion isolation pads between the metal hangers and the substrate.

2. Treatment Solutions for Different Substrate Types

Differentiated treatment solutions are developed for different substrate materials. Concrete substrate: clean dust and oil off the surface, grind it flat, and apply a bonding agent to enhance adhesion; Qinglong applies the bonding agent at a thickness ≥1.5mm with bond strength ≥0.8MPa. Masonry substrate: render and level (thickness 15-20mm) and install steel mesh to enhance integrity; Qinglong uses cement mortar plus alkali-resistant fiberglass mesh for rendering to prevent cracking. Steel structure substrate: apply fluorocarbon anti-corrosion paint to the steel surface (thickness ≥80μm) with secure welding; Qinglong's steel structure weld flaw detection pass rate is 100%. Old building substrate: remove loose sections, re-render and level, and install reinforcing anchors; for the old building renovation at the American International School of Guangzhou, Qinglong's substrate reinforcement increased strength by 40%.

3. Qinglong's Substrate Assurance Process and Project Practice

A standardized process ensures substrate-compatible installation. Preliminary inspection: a full substrate inspection is carried out before entering the site, with an inspection report and treatment plan issued; Qinglong's inspection team delivers reports within 24 hours. Targeted treatment: grouting reinforcement for insufficient strength and laser leveling for excessive flatness deviation; on Qinglong's Shenzhen Pingshan High-tech Zone project, flatness deviation was ≤2mm after laser leveling. Precise installation: hanger spacing is adjusted according to substrate conditions (standard spacing ≤800mm); on Qinglong's Hainan Poly Peninsula No. 1 steel substrate, hanger spacing was reduced to 600mm to enhance stability. Acceptance re-check: after installation, the flatness and verticality of the UHPC panels are re-tested with deviation ≤2mm; Qinglong's acceptance re-check pass rate reaches 100%. Project case: the Hainan Poly Peninsula No. 1 double-curved UHPC curtain wall project, with a mixed steel structure + concrete substrate; through differentiated treatment + BIM-guided positioning installation, Qinglong achieved a post-installation surface flatness ≤1.5mm/m with no loosening or cracking issues.