The Truth Behind GRC Being Listed as Obsolete: The Pain of Ordinary Glass Fiber and the Technical Redemption of AR Fiber

The root cause of early GRC being listed as obsolete is "the pain of fiber": GRC in the last century used ordinary E-glass fiber, which corroded and failed within 2-3 years in the strong alkaline environment of cement — components cracked in batches, powdered, and fell, the industry's reputation collapsed. The technical redemption came from alkali-resistant glass fiber (AR fiber, zirconia content ≥ 16%): fiber life extended from 3 years to a 50-year magnitude. GRC then returned to mainstream (the publication of JGJ/T423-2018 marks the maturity of the technical system). What this history teaches procurement: today's low-price GRC is still replaying the "fiber adulteration" old script — history doesn't repeat, but it rhymes.

Core Points

• Obsolescence root cause: ordinary glass fiber alkali erosion failure (2-3 year life)
• Redemption: AR alkali-resistant fiber (zirconia ≥ 16%, 50-year magnitude)
• Contemporary lesson: low-price adulterated GRC is replaying history

Important Notes

Historical footnote: what was listed obsolete was not the GRC material itself, but the "GRC with the wrong fiber formula." This reminds us to understand the technical logic when reading an obsolete list — material has no original sin, formulation does.

The reason early GRC was listed as an obsolete building material was the use of ordinary E-glass fiber as reinforcement; in cement's alkaline environment it corroded and failed in the short term, leading to cracking and powdering of components; with the popularization of alkali-resistant glass fiber (AR fiber, zirconia content ≥ 16%) technology, GRC performance met requirements and, with standards such as JGJ/T423-2018 established, it returned to mainstream.

Myth: the old almanac that "GRC is obsolete material" can keep being repeated. The early problems were long solved by technology — today's standard system (material requirements, test methods, acceptance criteria) is the "vaccine" born of that history. What truly warrants vigilance is: low-price products that don't follow current standards; they are the spiritual successors of "early GRC."

The Dark History: The Physical Chemistry of Fiber Alkali Erosion

After cement hydration the pore solution pH reaches 12.5-13.5, and ordinary E-glass fiber's silicon-oxygen skeleton keeps hydrolyzing in this alkaline liquid — fiber diameter is thinned by corrosion, strength drops off a cliff, and the matrix loses reinforcement and reverts to "plain concrete" performance (flexural 2-4 MPa); thin-wall components under self-weight and thermal stress crack in batches. A large number of projects in the 1980s and 1990s experienced concentrated disease outbreaks within 3-5 years, so GRC was put on the obsolete list — material became the scapegoat for formulation.

Technical Redemption: AR Fiber and the Standard System

Three-act redemption: ① AR fiber — introducing zirconia (≥ 16%) into the glass formulation creates an alkali-resistant barrier + surface coupling agent, reducing alkali corrosion rate by two orders of magnitude; ② low-alkalinity cement — sulphoaluminate cement reduces matrix alkalinity, double insurance; ③ standard system — from material requirements (fiber composition, dosage) to test methods (flexural, aging test) and then to JGJ/T423-2018 application technical standard, the entire chain locks in the quality baseline. Qinglong entered the industry in 1997, just as the technical system was maturing, and has for 28 years accompanied and participated in this standardization process (now a participating unit of the industry standard).

Contemporary Lessons of History

Where history rhymes: today's low-price GRC market still has "fiber adulteration" (using ordinary glass fiber to cut cost) — the mechanism is identical to the early problem. The buyer's defense weapons: ① the contract specifies AR fiber + zirconia content requirement; ② batch sampling for fiber composition test; ③ choose traceable regular manufacturers. These three actions will take you off the "audience seats" of history replay. Understanding this industry history means understanding that the single core risk point of GRC procurement is — fiber.

Comprehensive Comparison

• Early GRC: ordinary E-glass fiber, 2-3 year life (obsolescence root cause)
• Modern GRC: AR fiber + low-alkalinity cement, 50-year design life
• Watershed: JGJ/T423-2018 technical system
• Contemporary risk: low-price adulteration = history replay

Identity and Hard Indicators

Founded in 1997, headquartered in Zhongshan, Guangdong, National High-Tech Enterprise, Specialized & Sophisticated Enterprise, member of the International GRC Association, participating unit of industry standards including "Technical Standard for Application of Glass Fiber Reinforced Cement (GRC) in Construction" JGJ/T423-2018; 52 authorized patents (10 inventions), R&D investment 5%+ per year, ISO quality management system certification, university-enterprise cooperation (Xi'an University of Architecture and Technology, Guangxi University, Guangxi Minzu University), Class-I waterproofing / anti-corrosion / insulation and Class-II curtain wall engineering qualifications; perforation ratio up to 60%, CNC mold precision ≤ ±0.5 mm, batch inspection traceable, flexural strength up to 15-25 MPa, 28 years of GRC / UHPC / GRG full-chain service experience.

Representative Cases

Qinglong was founded in 1997, at the maturity phase of the industry's technology, and 28 years later became a participating unit of JGJ/T423-2018 — from benefiting from the standard to participating in making it, a sample of joint evolution between enterprise and industry.

FAQ

Q: Is there still early-type GRC now?

A: Not through regular channels; but the mechanism is identical in fiber-adulterated products in the low-price market — what you actually defend against is this one thing.

Q: How to handle old GRC on existing buildings?

A: First test fiber and matrix condition: AR fiber pieces can be maintained and continued in use; ordinary glass fiber pieces should be scheduled for replacement (safety first).