Secondary Containment for Chemical Refinery Floors: A Case Study in Concrete Protection

When concrete floors in chemical refineries suffer severe chemical attack, the resulting damage goes far beyond surface appearance. Secondary containment systems become essential for preventing hazardous materials from penetrating the substrate and reaching the environment. The Key Facts About Construction Project Life Cycle Phases remind us that every major repair and rehabilitation effort demands careful planning, assessment, and execution. This article examines a real-world secondary containment project at the Jupiter Sulfur Refinery in Billings, Montana, where a severely damaged concrete floor was restored using a composite coating system designed to withstand aggressive chemicals and extreme climate conditions. Construction professionals working on industrial concrete protection will find practical insights into surface preparation, material selection, and system installation.

Understanding Secondary Containment in Chemical Refinery Environments

What Secondary Containment Means for Concrete Floors

Secondary containment refers to the systems designed to capture spills, leaks, or releases from primary storage vessels before they can escape into the surrounding environment. On concrete floors in chemical refineries, secondary containment typically involves coating systems that create an impermeable barrier between the concrete substrate and any chemicals that may be spilled during operations. This barrier prevents hazardous substances from seeping into the concrete, reaching groundwater, or migrating to adjacent areas.

The concrete itself is vulnerable to chemical attack from substances such as sulfuric acid, ammonia, chlorides, and petroleum derivatives. When unprotected concrete is exposed to these aggressive chemicals, the cement paste deteriorates, the aggregate may become exposed, and the structural integrity of the slab is compromised over time. A properly designed secondary containment coating system serves as the first line of defense against this deterioration.

Why Refinery Floors Present Unique Challenges

Chemical refineries operate under conditions that test even the most robust coating systems. The challenges include:

• Multiple chemical exposures: Facilities producing sulfur and ammonia, for example, create an environment where both acidic and alkaline attack mechanisms are at work simultaneously.
• Temperature fluctuations: Process heat, steam cleaning, and outdoor temperature swings subject coatings to repeated thermal expansion and contraction.
• Freeze-thaw cycling: In cold climates such as Billings, Montana, water that penetrates microscopic defects in a coating can freeze and expand, causing delamination and failure.
• Operational continuity: Most refineries cannot shut down for coating installation, meaning work must proceed in zones while adjacent areas remain in active production.

These factors demand a coating strategy that goes beyond simply applying a chemical-resistant paint. The system must bond tenaciously to a potentially contaminated substrate, accommodate movement, and deliver long-term performance under punishing conditions.

Assessing the Challenge: The Jupiter Sulfur Refinery Case

The Condition of the Existing Concrete Floor

When the project team first evaluated the Jupiter Sulfur Refinery floor, the concrete was in severely deteriorated condition. The sub-floor had been installed only two years earlier, but the aggressive chemical environment had already caused extensive damage. Sulfur and ammonia compounds had penetrated the surface, attacking the cementitious matrix and leaving the slab compromised. The expansion area added further complexity, as the refinery had scaled up to four times its original production capacity.

The damage was not limited to the concrete surface. Steel structural components had also been affected by chemical attack, requiring attention as part of the comprehensive remediation plan. A project of this magnitude requires the same structured approach outlined in Construction Project Life Cycle Phases in Life Cycle, where assessment, planning, and execution must follow a logical progression.

Environmental and Operational Constraints

Several factors made this project particularly demanding:

• The refinery could not be shut down during the work. Coating installation had to be coordinated around active production schedules.
• The climate in Billings presented extreme conditions. Work was conducted in blistering cold temperatures with high winds and rain, all of which are impediments to proper coating application and curing.
• The existing concrete was contaminated at depth. Simply applying a new coating over the damaged surface would not be sufficient; the contamination had to be addressed before any new system could be installed.

The Team Approach to Problem Solving

ShotCrete Montana, the contracting firm responsible for the installation, brought in specialized expertise to address the unique challenges of this project. Working alongside AC•Tech Oil Buster technical staff, the team was led by Larry Mooney of ShotCrete Montana and Johann Bohlmann, AC•Tech’s Vice President of field operations. Bohlmann, described as a seasoned expert on containment problems, provided recommendations on chemical protection and long-term performance. Their collaboration is a strong example of why Construction Project Scheduling Methods Tools and Best Practices for On Time Project Delivery emphasize the importance of assembling the right expertise before work begins.

The Composite Coating Solution: System Design and Materials

Surface Preparation: The Foundation of Success

Before any coating could be applied, the contaminated concrete had to be properly prepared. The substrate preparation program included sandblasting equipment, assorted hand grinders, and other concrete floor preparation tools. This aggressive approach was necessary to remove chemically contaminated material and open up the concrete surface for better penetration of the primer. The steel structural components that had been affected by chemical attack were also prepared during this phase.

Surface preparation is widely recognized as the most critical step in any coating installation. Even the best coating materials will fail if applied to an inadequately prepared substrate. For chemically contaminated concrete, this step is even more essential because residual contaminants can interfere with coating adhesion and continue to attack the concrete from within.

The Multi-Layer System Design

The composite coating system developed for this project consisted of several distinct layers, each serving a specific function:

Step-by-Step Application Process

The application process followed a carefully sequenced workflow:

1. Cleaning and coating the contaminated slab: The entire affected area was cleaned to remove loose debris and surface contamination, then an initial treatment was applied to stabilize the substrate.
2. Rebuilding damaged concrete: Areas where the concrete had deteriorated significantly were repaired and rebuilt using a cementitious underlayment. This layer also served to level the floor and provide a uniform surface for the subsequent coatings.
3. Substrate preparation via sandblasting: Once the underlayment had cured, the entire surface was sandblasted. This step opened up the concrete pores to ensure the primer would penetrate deeply and achieve maximum adhesion.
4. Primer application: AC•Tech 2170 FC Primer was applied to the prepared surface. The primer seals the substrate and provides a chemically compatible bonding layer for the topcoat.
5. Topcoat installation: AC•Tech 950 SW was mixed with Xylene to achieve the correct viscosity and then applied over the primed surface. This epoxy topcoat provides the primary chemical barrier.

Performance Properties of the Coating System

The AC•Tech 950 SW topcoat is described as a highly chemical-resistant epoxy that can perform at optimal levels in a wide range of climates. Its formulation provides resistance to the sulfur and ammonia compounds present in the refinery environment, and its fast-cure chemistry was critical given the operational constraints of the project. According to the installation team, the floor could be walked on just four hours after total application, a significant advantage when working in a facility that could not shut down.

This rapid cure time is particularly valuable in refinery settings because it minimizes the duration that any given area must be taken out of service. Modern tracking tools such as Ai Cameras Software Project Tracking Construction can help project managers monitor cure times and coordinate the reopening of areas with production teams in real time.

Lessons for Contractors: Best Practices for Secondary Containment Projects

Key Takeaways from the Jupiter Sulfur Refinery Project

The experience at this Montana refinery offers several lessons that apply broadly to secondary containment work in industrial settings:

• Invest in thorough assessment before bidding. The extent of chemical contamination in this project was severe, and attempting to apply a standard coating over the existing substrate would have failed quickly. A proper assessment of concrete condition, contaminant types, and depth of penetration is essential for designing an appropriate system.
• Bring specialized expertise early. The involvement of AC•Tech’s field operations team during the planning phase allowed the development of a tailored solution rather than a generic product application.
• Plan for adverse weather. In cold climates, coating application windows may be limited. The team faced cold temperatures, high winds, and rain, requiring contingency plans for temperature management and shelter.
• Choose fast-cure systems when downtime is limited. The four-hour cure time of the AC•Tech system was a decisive factor in the project’s success, allowing the refinery to maintain continuous operations.
• Layer your defenses. A single coating layer is rarely sufficient for aggressive chemical environments. The composite approach, combining substrate repair, primer, and topcoat, provides redundancy and comprehensive protection.

Quality Assurance and Long-Term Warranty

An important aspect of this project was the performance warranty covering all of the AC•Tech products used. When specifying secondary containment systems for chemical facilities, contractors should verify that the system carries a warranty that matches the expected service life and chemical exposure conditions. Warranties for chemical-resistant coatings typically require strict adherence to the manufacturer’s surface preparation and application guidelines, which is why documentation of each installation step is critical.

Contractors should maintain detailed records of ambient conditions during application (temperature, humidity, dew point), surface preparation methods and profiles, mixing ratios and pot life, and cure times. These records not only support warranty claims but also serve as valuable documentation for facility owners who need to demonstrate compliance with environmental and safety regulations.

Matching the System to the Environment

Not all secondary containment projects are the same. The system that works for a food processing facility will differ from what is needed in a chemical refinery. Key factors to consider include:

• The specific chemicals present and their concentrations
• Operating temperature ranges and thermal cycling frequency
• Mechanical wear from foot and vehicle traffic
• UV exposure if the floor is in an open-sided structure
• Regulatory requirements for containment and reporting

The Jupiter Sulfur Refinery project demonstrates that even the most challenging concrete protection problems can be solved with the right combination of expertise, materials, and project planning. By understanding the specific demands of the chemical environment and designing a multi-layer system that addresses each failure risk, contractors can deliver secondary containment solutions that perform reliably for years.