Utilize the to accurately reflect Concrete Code limits (e.g., setting the effective moment of inertia
This technical guide outlines the methods for modeling cracked sections, applying thermal variations, and generating compliant designs using the ATIR Engineering Software suite. Core Structural Modeling Capabilities
ATIR STRAP calculates the exact degradation of stiffness via its advanced slab and beam deflection routines. Rather than relying on a fixed, arbitrary reduction factor, the software applies code-based interpolation (such as the Branson formula or Eurocode 2 formulations) between the gross cross-section properties ( Igcap I sub g ) and the fully cracked properties ( Icrcap I sub c r end-sub
When we talk about "straps" (synthetic slings) and "beams" (lifting or structural supports) being "cracked" or "hot," we are entering the territory of
The unique, variable cross-section of a beaded beam creates localized areas of high stress concentration. atir strap and beamd with crack hot
: It supports combined sections of any shape, including cellular and castellated members. ⚠️ Important Note on "Cracked" Software
Managing the "Crack" State: Section Stiffness Property Reduction
If the "atir" strap has lost its tension due to a crack, a "hot-strap" technique is used. A new steel strap is heated until it expands, then it is bolted or welded across the crack in the beam. As the strap cools, it naturally contracts, creating a massive amount of "clamping force" that effectively pulls the crack shut and reinforces the beam. C. Specialized Sealants
Engineers should look for:
In a healthy beam, stirrups provide "confinement," keeping the concrete core compressed and strong. When the stirrups heat up, expand, and lose their stiffness, they fail to confine the concrete. This results in the rapid buckling of longitudinal rebars and catastrophic shear failure of the beam. 3. Classifying Heat-Induced Cracks in Beams
BEAMD is ATIR's specialized, integrated solution dedicated exclusively to the design, detailing, drafting, and scheduling of reinforced concrete (RC) beams. It is designed to complement the broader structural analysis performed in STRAP or can be used as a standalone tool for beam-focused projects.
If you are working on a specific foundation design, let me know: The of your strap beam and footings The magnitude of the loads causing the high stress The version of ATIR STRAP you are using
Use ground-penetrating radar (GPR) to verify rebar location and concrete cover depth, ensuring thermal degradation has not detached the concrete from the steel. Repair and Remediation Strategies Utilize the to accurately reflect Concrete Code limits (e
Ie=(McrMa)3Ig+[1−(McrMa)3]Icr≤Igbold cap I sub bold e equals open paren the fraction with numerator bold cap M sub bold c bold r end-sub and denominator bold cap M sub bold a end-fraction close paren cubed bold cap I sub bold g plus open bracket 1 minus open paren the fraction with numerator bold cap M sub bold c bold r end-sub and denominator bold cap M sub bold a end-fraction close paren cubed close bracket bold cap I sub bold c bold r end-sub is less than or equal to bold cap I sub bold g Iecap I sub e : Effective moment of inertia under load. Mcrcap M sub c r end-sub : Cracking moment of the concrete cross-section. Macap M sub a
When a beam already has a crack (even small), high temperatures cause at the crack tip, potentially leading to rapid failure.
Concrete and steel generally expand at similar rates under normal atmospheric conditions. However, when exposed to extreme heat, this compatibility breaks down. Concrete is a poor conductor of heat, creating a steep temperature gradient between the outer surface and the inner core of the beam. The Phenomenon of Thermal Gradient
Internal water turns to steam. If the steam cannot escape due to low concrete permeability, the internal pressure causes explosive popping, blowing off chunks of the outer concrete layer. 2. The Critical Role of Stirrups (Strap Reinforcement) : It supports combined sections of any shape,