Articles

WHAT IS AN EJ?   An engineering judgment (EJ) is a drawing typically generated in PDF format by a firestop manufacturer for a jobsite-specific application. They are generally submitted to contractors, customers, architects, or MEP consultants. EJs are recommended as a solution when a jobsite condition deviates from a tested firestop system. When creating EJs, firestop manufacturers must adhere to certain guidelines which are defined by local official authorities.  What is their purpose? Contractors and customers frequently encounter unique firestop applications at construction jobsites that require various arran...

Seismic strength checks are required for connections involving both structural and non-structural elements. Structural connections INTEGRITY are vital to ensure safety under seismic loading component especially for buildings whose integrity is of vital importance for civil protection.​ Seismic loading induces extreme load conditions in fastenings much above concrete cracks. During an earthquake, the anchors will need to cope with:​ With the launch and introduction of NSCP 7th edition in relation to ACI 318-14.  We can now calculate/ assess anchors on its suitability in seismic condition​. It now offers full...

Concrete cracks when tensile stresses in the concrete imposed by loads or restraint conditions exceed its tensile strength. Concrete is typically assumed to crack under normal service load conditions. Crack width and distribution are generally controlled through the use of reinforcement. The existence of cracks in the anchor vicinity can result in a reduced ultimate load capacity and increased displacement at ultimate load compared to uncracked concrete.  ACI 318 and IBC building codes assume cracked concrete as the baseline condition for design of cast-in-place and post-installed anchors. Crack width and distribut...

Unprotected or improperly protected cable and pipe penetrations have presented a subject of much concern to the fire-protection community. Vertical and horizontal penetrations provided one of the major contributing causes of the rapid, erratic spread of smoke and fire. These openings allow the smoke to spread beyond the electrical rooms and into occupied floors. As a result of these fires many countries, institutes or organizations developed codes, regulations and test standards to prevent fires and define common rules. But for specifiers, architects, owners as well as for installers, the complexity of this topic incr...

Maybe you read the article on how anchors can fail under tension and are waiting to know more about what happens to a fixing point when the force is perpendicular to the anchor direction (shear loads). This article will provide you with a greater understanding of shear load applications and share some tips for your next anchor design. 1. Steel failure under shear Failure might occur if the anchor size is too small, the number of fixing points is not enough, or simply due to the steel strength capacity. To increase the resistance, select a more resistant steel material, and increase the size and the number of anc...

You need to fix a column, a beam, or any other steel element to concrete without cast-in threaded rods in the concrete to fasten it down. Keep calm: post-installed anchor technologies are reliable alternative solutions to be considered for your project, when selecting qualified systems for the application, you run an accurate design and you prescribe good recommendations for a safe installation. When it comes to design, the bad news is that anchors can break in eight different ways. The good news is that you can rely on international codes and standards, references, software, and experienced engineers (like Hilti E...

KEEPING FIRE-RATED ASSEMBLIES FIRESTOPPED OVER THE LIFETIME OF THE BUILDING Many times, due to cost and budget restrictions, firestop is not considered or just considered as a minor issue. This is not necessary if building owners, architects, designers, and general contractors take the correct firestop specifications and measures in an early phase of the construction project. It is their legal responsibility.   Another key question is how to keep the firestopped walls and floors intact over the lifetime of the building. So it is not only relevant for new construction but especially when it comes to the occupancy...

Restriction of a fire and minimization of fire and smoke spread is a key target in all building codes and regulations. The easiest way to solve this challenge and the most cost-efficient solution for architects and designers is fire compartmentation. It is mandated in all national building regulations all over the world and provides precautions, limitations, clear rules on the size and location and type of construction of fire compartments. It is as well a concern for building owners and insurance companies, not only in respect to life safety, but also in respect to asset protection. But why is it so important, what a...

How many solutions are out there to fix an anchor plate? Stud and sleeve dowels, epoxy and hybrid injection mortar, torque-controlled bonded anchor, capsule adhesive, screw, undercut fastening: these are all fixing technologies offering different benefits, depending on the application and installation condition requirements (performance, flexibility, speed, suitability). How to pick the right one? The first step is to identify a short list of suitable anchor solutions by looking at a third-party qualification (aka ICC-ES when designing connections according to ACI 318/NSCP). What does this mean? Let’s assume you are...