A field condition survey is a critical process for assessing the current condition and performance of a building. This survey involves evaluating various structural and environmental factors to ensure the building’s integrity and functionality. By referencing original construction plans, specifications, and records of previous repairs, professionals can determine how the building was constructed, the strengths of its materials, and the intended purposes of its components. This information, combined with field observations, helps in identifying structural alterations, distress, and deviations from the original design.
Pre-Survey Preparations
Review of Construction Documents
Before conducting a field survey, reviewing available construction documents is essential. Plans, specifications, and records of previous repairs or additions provide insights into the type of construction and the materials used. These documents help identify the building’s design intent, which is crucial when assessing current conditions.
The type of concrete construction is a key focus. Some common configurations include:
- Plain Concrete: Often used in footings, dams, and residential structures.
- Cast-in-Place Reinforced Concrete: Frequently found in multi-story buildings and large infrastructure.
- Prestressed-Precast Concrete: Typically utilized in bridges and modular construction.
- Post-Tensioned Concrete: Common in long-span or heavily loaded structures.
Determination of Survey Scope
If original plans are available, field dimensions should be spot-checked for consistency. When plans are missing, professionals must measure existing conditions and create detailed hand-drawn sketches, including grids, elevations, and sections. The level of detail in these sketches depends on the survey’s requirements, which may range from basic layouts to intricate documentation.
Survey Procedure
Field surveys focus on verifying dimensions and recording any discrepancies or damage. Existing conditions are meticulously documented on field sketches or directly on construction drawings. This step ensures accurate assessments and creates a reliable record for further analysis.
Key Conditions to Document
Cracks
Cracks are among the most common indicators of structural issues. Surveyors measure and record crack types and widths. If cracks are deemed active, monitoring devices are installed to track movement over time.
Joints
The configurations and conditions of all joints are recorded, with particular attention to any deficiencies that may compromise structural performance.
Delamination
Delamination refers to the separation of concrete layers. Professionals identify areas with partial or full delamination and record their depths.
Spalling
Spalling, or the breaking away of concrete fragments, is documented with detailed notes on location, depth, and overall condition.
Paste Erosion
Paste erosion, often caused by chemical reactions or environmental exposure, is another critical factor. Surveyors record affected areas and investigate environmental conditions contributing to the problem.
Water Infiltration
Signs of water infiltration, such as active leaks, rust staining, or efflorescence, are carefully documented. This information helps assess the severity and source of water damage.
Exposed Steel
Exposed steel is a sign of significant wear or damage. The extent and condition of exposed reinforcement or embedded steel components are recorded.
Corrosion
Corrosion is often identified through surface staining caused by rusting embedded steel or surface-mounted components.
Structural Distress
Structural distress is assessed through visible signs such as excessive deflection, shear cracking, tension-zone cracking, and radial cracking around columns.
Freeze/Thaw Damage
Concrete subjected to freeze/thaw cycles may exhibit damage. Surveyors identify and record these areas, noting the depth of the deterioration.
Alkali-Silica Damage
Alkali-silica reactions can cause significant structural damage. Suspected areas are sampled for laboratory testing to confirm the condition.
Organic Growth
Organic matter growing on concrete surfaces indicates excessive moisture, which can lead to concrete deterioration. Surveyors assess both the moisture source and the potential obscuration of other damage caused by organic growth.
Documentation of Observations
All observed conditions and defects are thoroughly documented. Field sketches and photographs record the locations and types of damage. Previous repairs are noted, especially if they coincide with current defects, to evaluate their effectiveness.
The survey also includes documenting the general condition of the facility. Surface treatments, fixtures, equipment, and utilities are reviewed to ensure they are functional and do not contribute to building deterioration.
Conclusion
A comprehensive field condition survey is an indispensable tool for maintaining and restoring building performance. By systematically documenting structural and environmental conditions, professionals can identify underlying issues and propose effective remedies. These surveys not only preserve the structural integrity of buildings but also ensure they remain safe and functional for their intended use.