Why and When to Use Concrete Piles?

Concrete Piles and drilled shafts are an important category of foundations. Despite their relatively high cost, they become necessary when we want to transfer the loads of a a heavy superstructure (bridge, high rise building, etc.) to the lower layers of soil. Another reason for choosing a pile foundation is the condition and quality of soil layers. Based on how they transfer the load into the subsoil, piles can be… Read More »Why and When to Use Concrete Piles?

Deficient Shear Walls

Deficient Concrete Shear Walls

Reinforced concrete shear wall structures constructed in the 1970’s or earlier suffer from a number of deficiencies in design and detailing. This is around the time when seismic provisions emerged in the design codes, and changed the traditional strength-based design philosophy (EVOLUTION OF DESIGN CODES). In this article, we will briefly review common problems with deficient concrete shear walls. The focus will be on concrete frame structures, with and without shear… Read More »Deficient Concrete Shear Walls

Design of Concrete Shear Walls

Concrete Shear Walls Reinforced concrete (RC) shear walls have long been recognized as suitable structural systems, providing both lateral resistance and drift control in RC buildings. However older shear walls were typically designed mainly for combined actions of gravity loads and wind loading with no special seismic load consideration. Seismic provisions were only introduces in the 1970’s, and have since evolved to ensure they have adequate capacity and ductility against… Read More »Design of Concrete Shear Walls

Patch Repair

Patch Repair: Dos and Don'ts

What happens when the patch repair is only done in damaged area?  When a corrosion sign and rust stain appear on the concrete surface, it is the time to do something in order to stop corrosion propagation. Depending on corrosion type and propagation, the required intervention and precautionary measure are adopted. The remedial action may include patch repair, cathodic protection, ion extraction, sacrificial anode, etc. Regardless of what method is… Read More »Patch Repair: Dos and Don'ts

Patch Repair

Patch Repair: Dos and Don’ts

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What happens when the patch repair is only done in damaged area?  When a corrosion sign and rust stain appear on the concrete surface, it is the time to do something in order to stop corrosion propagation. Depending on corrosion type and propagation, the required intervention and precautionary measure are adopted. The remedial action may include patch repair, cathodic protection, ion extraction, sacrificial anode, etc. Regardless of what method is… Read More »Patch Repair: Dos and Don’ts

What is Ground Penetrating Radar

What is Ground Penetrating Radar

Ground Penetrating Radar (GPR) provides a cost-effective, nondestructive and reliable tool for scanning and imaging of sub-surface defects, voids, and objects. GPR was primarily developed and used in geophysics and geology for subsurface scanning and imaging. Since then, the method has been successfully adapted in many other disciplines including civil engineering. The multipurpose nature of ground penetrating radar and its broad range of applications, make it distinct from existing NDT… Read More »What is Ground Penetrating Radar

IOT - Intelligent Bridge Monitoring

Intelligent Bridge Monitoring

Have you ever imagined what would happen if highway bridges could speak?: “That I broke an arm? That I have a steel tendon ruptured? …” Well, they are not too far anymore. Last week, I had the chance to participate in a presentation by Jacques Cartier and Champlain Bridges Incorporated (JCCBI) in the GTA, and learned about this smart instrumentation for stress/strain monitoring installed bridge girders. This helped bridge owners… Read More »Intelligent Bridge Monitoring

ASR-Corrosion

Corrosion in Concrete

It is common to see map crack networks over the concrete elements of aged infrastructure along with leaching signs. It might be interesting to know that no structural collapse has been reported so far because of the ASR cracking in North America. However, the question arises as to whether it is required to manage ASR cracking within concrete structures. In this article, we will study the combined effect of corrosion… Read More »Corrosion in Concrete

Modeling Existing Shear Walls

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Modeling existing shear walls can be quite challenging. The first question to ask is how far we want to go – and how much we want to spend on- when it comes to modeling a wall structure. The modeling can be as simple as a beam-columns element, or as complex as a nonlinear 3D finite element model. The design and detailing of reinforced concrete shear walls is a straight forward… Read More »Modeling Existing Shear Walls

Reinforced Concrete Shear Walls

The chapter on seismic behavior and retrofit of existing reinforced concrete shear walls is still wide open. Researchers and engineers around the world are trying hard to develop new materials and innovative techniques for seismic upgrade of concrete structures. But why is this so important? Reinforced concrete shear walls have long been recognized as suitable structural systems, providing both lateral resistance and drift control in RC buildings. However these older… Read More »Reinforced Concrete Shear Walls