Encorus is pleased to welcome Jack Wolff back to Encorus Group. Jack worked with our Civil Testing Group last summer as an engineering technician, and now joins our Design Group as an Associate Mechanical Engineer. He recently graduated from Alfred State College with his Bachelors Degree in Mechanical Engineering Technology. Welcome, Jack!
One of the many services offered by Encorus Group’s Civil Materials Testing & Inspection Group is EIFS inspections. According to ASTM international, EIFS, or Exterior Insulation and Finish Systems, are an exterior wall system that consist of an insulation board attached to the substrate, a base coat, and a protective top coat. These systems offer constant insulation, and allow architects to design buildings without the added concern of choosing materials for insulation purposes.
EIFS were originally only used on commercial buildings, but have found their way into residential buildings as well. According to the EIFS Industry Members Association (EIMA), EIFS generally consist of:
• A water-resistive barrier (WRB) that covers the substrate
• A drainage plane between the WRB and the insulation board that is most commonly achieved with vertical ribbons of adhesive applied over the WRB
• Insulation board typically made of expanded polystyrene (EPS) which is secured with an adhesive or mechanically to the substrate
• Glass-fiber reinforcing mesh embedded in the base coat
• A water-resistant base coat that is applied on top of the insulation to serve as a weather barrier
• A finish coat that typically uses colorfast and crack-resistant acrylic co-polymer technology
EIFS claddings are becoming increasingly popular due to their energy savings and reduced environmental impact. EIFS can reduce air infiltration by up to 55% compared to wood or brick cladding. In addition to this, EIFSs are durable, aesthetically flexible, and are fire resistant.
Most EIFS do not have drainage systems, therefore if the moisture level becomes high enough, the substrate is subject to rotting, leading to the failure of the EIFS. According to the American Society of Home Inspectors (ASHI), there are several things to look for when examining an EIFS for moisture damage. Things noted by the ASHI to observe visually include, dark streaks at the bottom corner of the windows and where the ends of the gutters meet, obvious signs of physical damage such as dings or holes, and exposed mesh, the EIFS touching the roof shingles, and wrinkles in the EIFS. Another thing to observe is the condition of the caulk around the windows. If the condition is poor or non-existent, it is highly likely that there will be moisture damage to the EIFS. If the EIFS gives way and feels squishy, it may be loose or there may be a moisture build-up.
It is important to identify any issues with an EIFS, as it can save money and time in the construction process. If your construction site has EIFS that require inspection, contact Jeremy Lake at (716) 592-3980 ext. 133, or jlake@encorus.com.
When building any type of structure, it is important to make sure that the materials you are using are structurally sound to guarantee the integrity and longevity of the structure. Some of the most common materials that are used in modern construction are concrete products. Testing the integrity of concrete and other concrete products is referred to as petrographic testing. A full petrographic testing procedure is composed of two separate tests: the petrographic analysis and the air void analysis.
Petrographic analysis testing is performed on samples of hardened concrete or concrete products from construction sites, or existing concrete that has been exposed to natural elements. There are several reasons that a petrographic analysis may be necessary. They include the determination of:
• The condition of concrete in construction
• Causes of inferior quality, distress, or deterioration of concrete
• Probable future performance of the concrete
• Whether cement-aggregate reactions have taken place and their effects on concrete
• Whether the concrete has been subject to chemical attacks or the effects of freezing and thawing
• Potential safety concerns in the structure
• Whether concrete that has been subjected to fire is damaged
• Factors that caused a given concrete to serve satisfactorily in the environment in which it was exposed
• The presence and nature of surface treatments
• Investigation of the performance of the coarse or fine aggregate in the structure
Samples of the concrete product are taken by sawing off an appropriately sized piece (approximately one 6-inch diameter core) from the concrete at the field site. The procedure for a petrographic analysis includes a visual examination of the sample, followed by an additional examination using a stereomicroscope. If a conclusion cannot be drawn from the information gathered in the first tests, further testing may be done using petrographic or metallurgic microscopes, x-ray diffraction, or other chemical / physical tests.
A report on the findings is then prepared. If the concrete sample was being examined because of structural failure, this report details the interpretation of why the concrete failed based on the findings.
These procedures and reports are done by a concrete petrographer. Concrete petrographers need to be knowledgeable on concrete making materials, the processes of batching, mixing, handling, placing, and finishing of hydraulic cement concrete, composition and microstructure of cementitious paste, interaction of constituents of concrete, and the effects of exposure of concrete to a variety of conditions.
The second test that is used for the full petrographic testing procedure is the air-void analysis. This test is used to determine the air content, specific surface, void frequency, spacing factor, and paste-air ratio of the air-void system of the concrete sample. Examining these factors can help determine whether the concrete was damaged by the freeze / thaw cycle.
When concrete is exposed to the elements, water is likely to settle in the air-gaps. When the water freezes and expands, it could harm the structural integrity of the concrete. Therefore, it is important to calculate the size and frequency of the air-gaps to determine whether or not the concrete would be acceptable to use in construction.
The petrographic testing process is essential to the integrity of any concrete or concrete product structure. Without it, the concrete could be subject to structural failure that could have been prevented. If you need construction materials testing and inspection, including petrographic testing, contact Civil Laboratory Supervisor Jeremy Lake at (716) 592-3980 ext. 133 or jlake@encorus.com.
Atterberg Limits Testing is just one of the testing methods that Encorus’s Civil Testing Group uses to determine properties of soil. According to ASTM International, Atterberg Testing Limits are six limits of consistency in soils that were defined by Albert Atterberg. These limits include the upper limit of viscous flow, the liquid limit, the sticky limit, the cohesion limit, the plastic limit, and the shrinkage limit. In modern engineering, the term Atterberg Limits commonly refers to only the liquid limit, the plastic limit, and in some cases, the shrinkage limit.
The liquid limit of soil is the minimum amount of water that would be added to a set amount of soil to change its consistency to a liquid state, meaning that the soil cannot retain its shape. The liquid limit of soils can be determined by creating a paste using soil and a small amount of water and putting it in a liquid limit device. The paste is separated into two halves using a grooving tool, and then allowed to flow together from the shocks caused by repeatedly dropping the device’s cup in a standard manner. This process is repeated with different amounts of water in the paste and the results are plotted on a graph to establish the liquid limit.
The plastic limit of soil is similar to the liquid limit, but it is the amount of moisture that causes soil to display plastic characteristics rather than liquid or solid ones. The plastic limit can be determined using a rolling method where the soil sample with a recorded amount of water is rolled into a 3.2 mm thread and broken into smaller and smaller pieces until it cannot be re-rolled and broken down any more. This process is done twice, and then the average water content of both trials is calculated to determine that soil’s plastic limit. The plasticity index of a particular type of soil can be found by determining the difference between the plastic limit and the liquid limit.
The shrinkage limit of soil is the maximum amount of water in soil that makes it saturated, but still in a solid state. When you add water to soil, the volume increases. However, when a soil sample reaches its shrinkage limit, the volume of the soil does not decrease when the amount of water is decreased even further. The shrinkage limit can be found in a soil sample by determining the relationship between initial wet mass, initial volume, the dry mass, and the volume after drying.
According to the ASTM International Designation: D4318–17E1 , “The liquid limit, plastic limit, and plasticity index of soils are also used extensively, either individually or together, with other soil properties to correlate with engineering behavior such as compressibility, hydraulic conductivity (permeability), compactibility, shrink-swell, and shear strength”. These testing methods are crucial when it comes to determining what type of soil to use as a foundation for construction projects. The properties mentioned above will affect the soil’s ability to maintain its durability under different forms of agitation. Therefore, it is essential for construction professionals to test the soil before starting construction to ensure the long-term integrity of the structure being built.
Fun Fact Friday: Photo Edition
Did you know that wind turbines can be 300 to 400 feet tall and weigh up to about 350 tons? Encorus has had hands-on experience with wind turbines, providing Civil Testing services for the Arkwright Wind Farm! Learn more about Encorus’s larger-than-life Civil Testing experience here.
Encorus Group staff often visits the job sites where concepts are brought to reality. These visits are part of the materials testing and inspection services that Encorus offers. Our Civil Testing and NDE groups are also constantly visiting construction sites to perform testing and inspections. Members of our design group sometimes visit jobsites as well, to obtain measurements, observe construction, or answer questions. While visiting a construction site, it is important to remember to take safety precautions to avoid injury and prevent any work disruptions. Here are some things to keep in mind if you ever find yourself on an active construction site:
1. Wear a hardhat
On an active construction site, workers could be transporting materials above your head, with a crane, for example, or materials may not be secured. Hardhats will protect your head from any potential injury. Hardhats do have a shelf life! The date of manufacture should be printed on the inside of the hardhat, and it should be used for no more than 4-5 years from that date. OSHA, ANSI, and the hardhat manufacturer can offer specific guidance. In addition, factors such as excessive temperatures (ie, keeping your hardhat in your vehicle) can cause it to degrade more quickly, and be less effective in the event of an impact.
2. Wear a high visibility vest
It is important to make sure that can be easily seen on a construction site, so high visibility vests are required. If someone wears clothes that blend in with the materials on the construction site, they can be easily overlooked and subject to injury. High visibility outerwear makes you more noticeable, and reflective strips are essential to being seen in low light situations.
3. Wear appropriate footwear
Appropriate footwear includes boots or shoes with hard soles and preferably steel toes. Shoes with open toes, high heels, and soft soles are strongly discouraged as there are sharp objects that can be stepped on or heavy materials that can be dropped on feet. Construction sites are often unlevel, and appropriate footwear will decrease the chance of slipping or tripping.
4. Wear safety glasses
Any active construction site is a hazard for your eyes. Dirt, dust, rocks, and construction materials are constantly moving around, including through the air. Wear safety glasses to protect your eyes from flying objects.
5. Wear long pants to cover your legs
Sharp object may be sticking up, and your legs may be subject to scratches and cuts. Skirts, shorts, and dresses are discouraged on the construction site. Wearing long pants will protect your legs from any harm
6. If you have a guide, be sure to stay close to them as you move around the site
It is easy to get lost on construction sites, so if you do not know where you are going, it is best to stick with your guide on the visit. They are probably more familiar with the site than you are as a visitor, and will be able to guide you on a safe route and avoid hazards
7. Be aware of your surroundings
It is common sense to have a general awareness of the construction site you are visiting. If there is a place where the materials appear to be unstable or if workers are vigorously working, do not approach that area. Make eye contact with machinery operators when crossing the machine’s path. Safety is the first priority, and if you approach an area where people are working, they make have to stop and disrupt progress until you leave
8. Do not touch anything
It is advised not to touch any materials on the construction site, especially any loose wires. Those wires may be live, and the materials could be sharp or recently painted.
In general, follow all instructions that your guide or the site supervisor may give you. They will know the best way for you to safely navigate the site. You not only want to be safe, you want to be welcomed back in the future! Remember that your safety on a jobsite affects the safety of others as well – if you get hurt, others may get hurt as well trying to help you. Stay safe!
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