What Effect Can Surface Acid Etching Treatment Achieve on UHPC Panels?

Surface pickling treatment of UHPC panels achieves four core effects: "removing laitance, enhancing adhesion, creating stone-like texture, and improving stain resistance." After pickling, UHPC panel surface roughness reaches 40-70μm, with adhesion improved by over 30%. Through precise control of pickling parameters, Qinglong ensures uniform and stable pickling results for UHPC panels in projects such as Shanghai New World Plaza and Dongting Lake Museum.

I. Core Effects: The Value of Pickling Treatment

Pickling treatment optimizes surface performance in a targeted manner. Removing laitance and impurities: pickling dissolves cement laitance, dust and other impurities on the UHPC surface, revealing the natural color of the aggregate; after Qinglong's pickling, the surface laitance removal rate reaches 99% with no residue. Enhancing surface adhesion: pickling forms uniform micropores and a rough surface, with roughness changed from ≤0.1mm to 0.04-0.07mm; when subsequently applying coatings or pasting facing materials, adhesion improves by 30-50%; after Qinglong's pickling, the bond strength between UHPC and coating is ≥1.5MPa. Creating stone-like texture: pickling highlights the aggregate grain, simulating the rough texture of natural stone, with realism improved by 20%; the UHPC stone-imitation panels at Qinglong's Dongting Lake Museum project match the texture of natural granite after pickling. Improving stain resistance: the microporous structure absorbs protective agents to form a denser protective layer, improving stain resistance by 40%; after Qinglong's pickling, silane impregnation agents are applied, making oil stains and rainwater difficult to penetrate.

II. Pickling Process Parameters: Key Control of Results

Precise parameters ensure uniform pickling results. Acid solution ratio: hydrochloric acid (5-8% concentration) or phosphoric acid (8-10% concentration) is used, with a corrosion inhibitor (0.5-1% dosage) optionally added to avoid over-corrosion; Qinglong adjusts the acid concentration according to UHPC surface conditions, with an error of ≤±0.5%. Pickling time: pickling at room temperature (20±5℃) for 10-15 minutes; for every 10℃ rise in temperature, the time is shortened by 2-3 minutes; Qinglong determines the optimal time through trial pickling to avoid under- or over-pickling. Cleaning and neutralization: after pickling, rinse with clean water (water pressure ≥0.3MPa), then neutralize with an alkaline solution (sodium carbonate concentration 2-3%) to restore the pH value to 6-8; Qinglong's rinsing time is ≥5 minutes with no acid residue.

III. Qinglong's Pickling Management and Project Practice

Standardized processes ensure treatment quality. Pretreatment: surface oil stains and dust are cleaned before pickling, and pickling is performed after drying; Qinglong's pretreatment uses high-pressure water jets plus neutral cleaning agents, achieving a surface cleanliness of 98%. Quality inspection: after pickling, surface roughness (40-70μm) is checked for signs of over-corrosion (no exposed reinforcement, no cracks); Qinglong uses a roughness meter and magnifying glass for inspection, with a pass rate of 99.5%. Project cases: the UHPC wood-grain translucent panels at Shanghai New World Plaza show prominent wood grain texture after pickling, improving light transmission uniformity; the UHPC stone-imitation panels at Dongting Lake Museum display clear aggregate grain after pickling, with a realistic stone-like texture. Qinglong's tip: pickled UHPC panels must be coated with a protective agent within 24 hours to prevent surface weathering and ensure long-term stable results.