How to Reinforce an Industrial Building with Cracks

This project involves the structural strengthening of an existing industrial production facility that has been in operation for many years. Due to increased loads from production equipment installed subsequently, the effects of long-term vibration, concrete shrinkage, and thermal stresses, the primary and secondary beams have developed structural cracks and exhibit insufficient flexural load-bearing capacity. Only localized areas of the floor slabs present minor shrinkage cracks; thus, the structural distress in these areas is relatively mild.

Based on the results of structural stress verification calculations and the observed on-site structural defects, a targeted strengthening scheme has been designed as follows:

Beam Strengthening : High-strength unidirectional carbon fiber fabric is applied continuously along the entire length of the beam's tension zone (at the bottom) to enhance its flexural load-bearing capacity. Additionally, U-shaped carbon fiber stirrups are applied transversely to the beam's sides and bottom to bolster shear resistance, arrest crack propagation, and comprehensively improve the beam's overall stiffness and durability. The carbon fiber fabric application utilizes a specialized system of epoxy primer, leveling putty, and impregnating resin to ensure effective composite action and load-sharing between the carbon fiber and the concrete substrate.

Slab Strengthening: Strengthening measures for the floor slab are limited to localized areas on the underside exhibiting minor hairline cracks; in these specific areas, carbon fiber fabric is applied in a grid pattern to seal the cracks and control their further propagation. As the overall structural performance of the floor slab remains sound, extensive, large-scale strengthening is deemed unnecessary.

This factory building reinforcement project precisely targets key structural defects, prioritizing the strengthening of beams using carbon fiber fabric while supplementing this with localized slab reinforcement. It specifically addresses issues such as insufficient beam load-bearing capacity and structural cracking, while also attending to minor defects in the floor slabs. By fully leveraging the advantages of carbon fiber reinforcement technology—namely its ease of application, superior strengthening efficacy, and exceptional durability—the project ensures the efficient and effective completion of the structural upgrade.