Glassfiber Mesh: A Visit To The Lab – What Key Data Should We Focus On in An Authoritative Test Report?

Among all test items, the alkali-resistant tensile strength retention rate is the most critical durability indicator for reinforcement mesh. It simulates the degree of strength degradation of the material after long-term service in the highly alkaline environment (pH>12.5) of cement mortar.

Test Method: According to Appendix B of JGJ144-2019 or the GB/T 20102 standard, samples are immersed in a specific alkaline solution for a set period, after which their tensile breaking strength is tested and calculated as a percentage of the initial strength.

Acceptance Criteria: For mesh used in exterior insulation systems, JGJ144-2019 requires the alkali-resistant tensile strength retention rate to be no less than 80% . This means that after alkaline exposure, the product must retain at least four-fifths of its original strength. The higher the retention rate, the more reliable the long-term performance. The building materials industry standard JC/T 841-2007 sets a requirement of no less than 75%, with the difference stemming from the varying stringency of the application scenarios.

Our Advice: Check whether this value in the report is ≥80% (for exterior insulation use) and note whether the testing standard cited is JGJ144-2019 or JC/T 841.

Tensile breaking strength determines the fundamental load-bearing capacity the reinforcement provides to the render layer and is the basic guarantee for resisting wind loads and thermal stress.

Test Method: Tested according to GB/T 7689.5 using the strip method. Reports typically provide breaking strength values for both the warp and weft directions.

Acceptance Criteria: Different grammage meshes correspond to different strength requirements. For example, alkali-resistant mesh for exterior insulation with a grammage of 160g/m² typically requires warp and weft tensile breaking strength to be ≥1200N/50mm. Products with higher grammage have correspondingly higher requirements.

Our Advice: Compare the measured values in the report with the product's nominal values and confirm that both warp and weft data meet the specified requirements.

Elongation at break reflects the material's ability to deform before fracturing and is a core indicator for understanding its "flexibility."

Acceptance Criteria: According to JC/T 841-2007, the elongation at break should be no greater than 4.0% . This indicates that such reinforcement mesh is a low-elongation material, designed on the principle of rigid reinforcement – providing high-strength constraint to limit crack propagation.

Our Advice: Confirm whether the elongation at break in the report is ≤4.0%. Excessively high elongation may indicate insufficient rigidity to effectively constrain substrate deformation.

Grammage is a comprehensive reflection of fiber content, coating thickness, and weave density, directly linking the product's mechanical properties to its procurement cost.

Acceptance Criteria: According to JC/T 841-2007, the measured value should be within ±8% of the nominal value. For instance, a product nominally 160g/m² should have a measured value between 147.2 and 172.8g/m². Excessive deviation may indicate unstable production processes or the risk of artificially inflating grammage with cheap fillers.

Our Advice: Compare the measured value in the report with the product specification sheet and verify that the deviation falls within the allowable range.

For reinforcement mesh manufactured using alkali-resistant glass fiber, the zirconia (ZrO₂) content is a key chemical component determining its inherent alkali resistance.

Acceptance Criteria: According to JC/T 841-2007, the ZrO₂ content should be (14.5±0.8)% ; or the combined total of ZrO₂ and TiO₂ should be ≥19.2%, with ZrO₂ content ≥13.7%. Zirconia acts as a "chemical sacrificial layer," preferentially reacting with penetrating hydroxyl ions, consuming the aggressive medium and protecting the fiber body.

Our Advice: If the product claims to use alkali-resistant glass fiber, the report should include test data for ZrO₂ content that meets the above standards.

An authoritative test report for glassfiber mesh is not only an endorsement of product quality but also a guarantee of long-term project reliability. As decision-makers, we don't need to be overwhelmed by all the data, but the four core indicators – Alkali-Resistant Tensile Strength Retention Rate (≥80%), Initial Tensile Breaking Strength, Elongation at Break (≤4.0%), and Mass per Unit Area (±8%) – deserve your close attention every time you review a report.