Luoyang Cigarette Factory Relocation Project

The fundamental cause of cracking in conventional concrete floors is that shrinkage stress during curing exceeds the tensile strength of the material. The typical approach is to cut joints to divide the floor into small panels, allowing each panel to shrink freely and avoid restraint-induced cracking—but the joints themselves become weak points. For a cigarette factory workshop, this structural characteristic leads to specific operational issues: joints become dust accumulation死角, making it difficult to maintain cleanliness; spalled concrete debris from joint edges compromises workshop hygiene; vibration and impact from forklifts crossing joints accelerate edge deterioration; and frequent maintenance disrupts production continuity.

Prestressing principle: Compressive stress is intentionally introduced into the floor concrete, keeping it in a compressed state. When shrinkage stress develops, it must first overcome this active compressive stress before tensile stress can cause cracking. With proper design, the active compressive stress is sufficient to offset the tensile stress from normal concrete shrinkage, allowing reduced joint spacing while maintaining floor integrity. This project achieved a panel size of 2,500 m² with minimal joints, significantly reducing joint count compared to conventional solutions. Construction organization: The 20,000 m² area required a systematic phased construction plan. The floor was constructed in sequential zones, with prestressing tensioning closely coordinated with concrete curing to ensure each zone achieved the required concrete strength before tensioning. BICP's technical team established on-site quality control checkpoints, recording and tracking key parameters such as flatness, prestressing force, and concrete strength throughout the process. The project spanned several months, with BICP's team stationed on-site full-time, executing the phased construction plan. Tensioning data for each zone was recorded, forming a complete quality documentation. BICP coordinated closely with the owner and general contractor to manage interfaces between floor construction and other workshop activities, ensuring overall project schedule and floor quality were mutually aligned.

Project Background

The Luoyang Cigarette Factory relocation project of China Tobacco Henan Industrial Co., Ltd. is a key construction project in China's cigarette manufacturing industry. The production workshop imposes stringent requirements on the floor system: tobacco products are highly sensitive to dust, so the floor must not generate dust or sand; production equipment is precision-mounted directly on the floor, requiring zero settlement or cracking; and frequent forklift and material handling traffic demands high wear resistance and joint stability to ensure operational efficiency.

During the scheme evaluation phase, traditional jointed floor solutions showed clear drawbacks: joint spacing ≤6 m resulted in numerous joints across the 20,000 m² workshop, creating dust accumulation死角 and cleaning difficulties; joint edges were prone to spalling under repeated forklift loading, compromising hygiene and safety; and the floor required maintenance every 3–4 years, causing production interruptions.

BICP proposed a post-tensioned integrated floor system. After technical evaluation and feasibility assessment, the owner adopted the solution, making this project a representative early application of BICP's post-tensioned integrated floor technology in industrial settings.

Technical Challenges

The fundamental cause of cracking in conventional concrete floors is that shrinkage stress during curing exceeds the tensile strength of the material. The typical approach is to cut joints to divide the floor into small panels, allowing each panel to shrink freely and avoid restraint-induced cracking—but the joints themselves become weak points.

For a cigarette factory workshop, this structural characteristic leads to specific operational issues: joints become dust accumulation死角, making it difficult to maintain cleanliness; spalled concrete debris from joint edges compromises workshop hygiene; vibration and impact from forklifts crossing joints accelerate edge deterioration; and frequent maintenance disrupts production continuity.

Solution

Prestressing principle: Compressive stress is intentionally introduced into the floor concrete, keeping it in a compressed state. When shrinkage stress develops, it must first overcome this active compressive stress before tensile stress can cause cracking. With proper design, the active compressive stress is sufficient to offset the tensile stress from normal concrete shrinkage, allowing reduced joint spacing while maintaining floor integrity.

This project achieved a panel size of 2,500 m² with minimal joints, significantly reducing joint count compared to conventional solutions.

Construction organization: The 20,000 m² area required a systematic phased construction plan. The floor was constructed in sequential zones, with prestressing tensioning closely coordinated with concrete curing to ensure each zone achieved the required concrete strength before tensioning. BICP's technical team established on-site quality control checkpoints, recording and tracking key parameters such as flatness, prestressing force, and concrete strength throughout the process.

Implementation

The project spanned several months, with BICP's team stationed on-site full-time, executing the phased construction plan for the 20,000 m² post-tensioned integrated floor. Each zone's concrete strength was verified before tensioning, and tensioning data for each zone was recorded, forming a complete quality documentation. BICP coordinated closely with the owner and general contractor to manage interfaces between floor construction and other workshop activities, ensuring overall project schedule and floor quality were mutually aligned.

Delivered Value

After commissioning, the workshop floor maintained good integrity over years of operation, with no significant cracking or joint deterioration. Dust accumulation was notably reduced compared to conventional jointed floors, meeting the high hygiene standards of cigarette manufacturing. Maintenance frequency was effectively lowered, reducing production downtime caused by floor repairs and positively impacting continuous production.

This project is an early representative application of BICP's post-tensioned integrated floor technology in the tobacco industry and served as an important reference for subsequent promotion of BICP's Taiping post-tensioned integrated floor system in China's tobacco sector.

Reference Significance

This project is a representative early engineering practice of BICP's Taiping post-tensioned integrated floor technology in industrial facilities. It validated the engineering applicability of the post-tensioned integrated floor solution under high-cleanliness and high-forklift-traffic conditions, providing a reference for industrial facilities in tobacco, food, precision manufacturing, and other sectors with stringent floor hygiene and stability requirements.

After commissioning, the workshop floor maintained good integrity over years of operation, with no significant cracking or joint deterioration. Dust accumulation was notably reduced compared to conventional jointed floors, meeting the high hygiene standards of cigarette manufacturing. Maintenance frequency was effectively lowered, reducing production downtime caused by floor repairs and positively impacting continuous production. This project is an early representative application of BICP's post-tensioned integrated floor technology in the tobacco industry and served as an important reference for subsequent promotion of BICP's Taiping post-tensioned integrated floor system in China's tobacco sector. It validated the engineering applicability of the post-tensioned integrated floor solution under high-cleanliness and high-forklift-traffic conditions, providing a reference for industrial facilities in tobacco, food, precision manufacturing, and other sectors with stringent floor hygiene and stability requirements.