Thank you, Alex, for your insightful commentary, and for also increase the ASCE's body of knowledge.
In my view, This behavior is attributed to improved confinement of the concrete core, which can increase the compressive strength by a factor of up to two. Numerous studies in the literature indicate that encasement or the use of steel tubes significantly enhances the load-bearing capacity of composite sections.
It was used the system in the he 1997 Sherbrooke Pedestrian/Bikeway Bridge in Quebec, Canada, was the world's first structure to use Reactive Powder Concrete (RPC) with a 200 MPa compressive strength.
See:
reactive powder concrete (RPC)
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Andre Newinski S.E., M.ASCE
Structural Engineer - ASCE 7-28 Member: Main Committee and Subcommittee
AN
Santo AngeloBrazil
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Original Message:
Sent: 02-02-2026 01:52 PM
From: Alex Thomas
Subject: Testing PVC
PVC tubes 6" inch filled with concrete can be withstanding medium load struts experience of AC pipes filled with concrete for ornamentation columns this practice is seldom failed on small loads and sustainable anybody interested shall be tested in the laboratory for buckling failure of PVC and shear strength of PVC.
PE; Alex Thomas MASCE FIE PEng
Cochin Kerala India
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Alex Thomas R.Eng, C.Eng, M.ASCE
Senior Site Engineer
Geo Structurals Pvt Ltd
ErnakulamAlexThomasR.Eng, C.Eng, M.ASCEIndia
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