DPA’s Commitment to Advanced Technology & Solutions
Equipment
Since DPA’s inception, the procurement and development of specialised equipment has been paramount. The forensic nature of investigations and design optimisation requires in-depth data analysis which demands that state of the art equipment and computer software be utilised. DPA uses a wide range of equipment, some of which has been developed specifically to DPA’s requirements and is considered proprietary equipment.
Data logging capabilities enable the capture of thousands of data units that are processed through DPA’s advanced software systems, resulting in in-depth statistical analyses and computer modeling. As a result, investigations and assessments can be refined to high levels of accuracy, positively influencing remedial decisions and associated budgets for our turnkey contracts.
Thermal Imaging
FLIR Infrared Camera
Thermal image
Our high-resolution infrared camera is able to detect small differences in the surface temperature of structures. This allows rapid detection of areas of delamination in structures, such as spalling concrete, or unbonded plaster (the thin delaminated patches heat up, and cool down, more quickly than the adjacent solid zones). Another key benefit is the location of areas of failed waterproofing, where the damp zone around the discontinuity shows as either warmer or cooler than its surroundings.
It is also possible to gain an immediate, visual representation of the surface temperature of an entire structure, which information can be critical when specifying repair materials or coatings. This can be done from a distance, without having to physically access the structure – a great benefit where access is limited or potentially unsafe.
Coring (Core Samples)
Coring Machine
Coring Sample
A core sample is a cylindrical section of (usually) a naturally occurring substance. Most core samples are obtained by drilling with special drills into the substance, for example sediment or rock, with a hollow steel tube called a core drill. The hole made for the core sample is called the "core bowling". A variety of core samplers exist to sample different media under different conditions. In the coring process, the sample is pushed more or less intact into the tube. Removed from the tube in the laboratory, it is inspected and analyzed by different techniques and equipment depending on the type of data desired.
Core samples can be taken to test the properties of manmade materials, such as concrete, ceramics, some metals and alloys, especially the softer ones.
Data Logger (Load Testing)
Data Logger end use during Load Testing
Data loggers offer many durable and weatherproof data logging solutions monitoring temperature, vibration, pressure, force along with vibrating wire strain gauge support.
This device measures the length, areas and volumes without any guess work. Equipped with advanced laser technology, the data logger delivers the measurements with maximum precision and reliability.
Electro-Potential Mapping
Half-Cell Meter
Measures the condition and potential corrosion of rebars and steel structures within concrete.
When corrosion occurs, the ferric oxide protective layer surrounding the concrete breaks down allowing an electrochemical reaction between the steel and the concrete.
In the half-cell test, a reference electrode is passed over the surface of the concrete and the potential voltage difference is recorded. These potential voltage readings show where corrosion is likely to be, or is currently present.
Desalination Electrochemical Treatment for Reinforced Concrete
Desalination Process
DPA TRM Unit →
The DPA TRM Unit is a transformer rectifier with inbuilt controls and data logging capabilities. The TRM Unit is rated to provide total output current and voltage to meet the required current demand and is used in the Desalination process.
Chloride extraction (Desalination) is an electrochemical treatment to halt and prevent reinforcement corrosion in chloride contaminated concrete. Chloride extraction is performed by applying an electric field between the reinforcement in the concrete and an anode mesh embedded in an electrolytic reservoir on the concrete surface. During treatment, chloride ions are transported out of the concrete by means of migration. Simultaneously, electrolysis at the reinforcement surface produces an alkaline environment.
Advantages
Chloride extraction offers major advantages over other methods of concrete repair.
- The cause of corrosion is addressed and removed
- The success of the treatment is documented on site
- The rebars are passivated throughout - not just in isolated areas
- The non-destructive nature of the treatment results in vastly reduced concrete break-out, which means:
- Major time-savings
- Less noise, dust and environmental pollution
- No need for expensive structural support
- Reduced risk of inducing micro-cracks
- The chloride extraction process is silent
- The need for permanent electronic monitoring is eliminated
- Architectural and exposed aggregate finishes can be maintained
Surface Profile Measurement
Surface Profile Measurement
Surface Profile gauges are commonly used to measure the profile height of a surface. The degree of the surface profile on the surface affects a coating’s overall performance and determines aspects such as adhesion, coverage and overall volume of coatings used. If the surface profile is too large the amount of coating required increases, otherwise there is a danger that the peaks remain uncoated thus allowing rust spots to occur. If the surface profile is too small there may be insufficient key for adequate adhesion leading to premature coating failure. To ensure the correct surface preparation optimises the performance of the coating and material usage, the profile height of a surface needs to be accurately assessed and measured and therefore it is essential to know this parameter as it determines the adhesion, coverage and overall volume of coating used.
Dry Film Thickness Tests
Dry Film Thickness Test
Dry Film Thickness is probably the most critical measurement in the coatings industry. It provides vital information as to the expected life of the substrate, the product’s fitness for purpose, its appearance and ensures compliance with a host of International Standards. Dry Film Thickness can be measured on either magnetic steel surfaces or non-magnetic metal surfaces such as stainless steel or aluminium using a digital coating thickness gauge. The principle of electromagnetic induction is used for non-magnetic coatings on magnetic substrates such as steel. The eddy current principle is used for non-conductive coatings on non-ferrous metals substrates.