Monthly Archives: May 2014

Yield Stress of a Material – Simple Explanation

Yield Stress of a Material – Simple Explanation Yield of a material is explained as the stress at which a material begins to deform irreversibly. Preceding the yield point, the material will deform elastically, meaning that it will return to its original shape when the applied stress is removed (i.e. no permanent, visible change in… Read More »

Bleeding in Concrete – Definition, Negative Effects & Control

Bleeding in Concrete – Definition, Negative Effects & Control Summary Use a more finely ground cement. Concretes made with high early strength (Type III) cement bleed less because the cement is ground finer than normal (Type I) cement. Use more cement. At the same water content, rich mixes bleed less than lean mixes. Use fly… Read More »

Lateral Torsional Buckling in Beams = Lateral Deflection + Torsion

Lateral Torsional Buckling in Beams = Lateral Deflection + Torsion Summary Lateral torsional buckling occurs when an applied load causes both lateral displacement and twisting of a member. This failure is usually seen when a load is applied to an unconstrained, steel I-beam, with the two flanges acting differently, one under compression and the other… Read More »

D-Cracking (Durability Cracking) – Cause & Prevention

D-Cracking (Durability Cracking) –  Cause & Prevention Summary D-cracking is cracking in concrete pavements caused by freeze-thaw cycles deteriorating the aggregate in concrete.  Water naturally accumulates at the base and sub-base layers under concrete.  When this water suffers from freeze-thaw cycles it wears on the durability of the concrete and begins to crack in the… Read More »

Carbonation of Concrete – Various Failure Mechanisms of Concrete

Carbonation of Concrete – Various Failure Mechanisms of Concrete What is Carbonation-Process Carbonation is the formation of calcium carbonate (CaCO3) by a chemical reaction in the concrete. The creation of calcium carbonate requires three equally important substances: carbon dioxide (CO2), calcium phases (Ca), and water (H2O). Carbon dioxide (CO2) is present in the surrounding air,… Read More »

Charles De Gaulle Airport, Paris Terminal Collapse in 2004

Charles De Gaulle Airport, Paris Terminal Collapse in 2004 Summary design for the building had little or no margin for safety cracking inside the concrete, weakened the complete structure rapid thermal enlargement  Aéroport DE Charles de gaulle is the most important airfield in Paris, France and also the second busiest airport altogether of Europe after… Read More »

Collapse of Enschede Stadium Roof ( 2011) – roof structure’s insufficient stability

[:en] Collapse of Enschede Stadium Roof ( 2011) – Direct Causes FC Twente wanted to increase stadium capacity by further extending the L-shaped extension completed in 2008 into a U-shaped one. On July 7, 2011, during work to extend De Grolsch Veste stadium, the roof of extension collapsed. The investigation conducted by the Dutch Safety… Read More »

1968: Ronan Point Disaster – Weaknesses in the design

1968: Ronan Point Disaster –  Weaknesses in the design. By Jordan Figueroa Building:  Ronan Point Location:  Newham, UK Year of Construction:  1968 Year of Failure:  1968 Type of Failure:  Progressive Collapse Construction Team:  Taylor Woodrow Anglian The Ronan Point disaster of Newham, UK occurred May of 1968 due to a gas explosion on the 18th… Read More »

1993 – Highland Towers Collapse, Malaysia

1993 –  Highland Towers Collapse, Malaysia Courtesy By Jamie Nalley On December 11, 1993 at 1:35pm, the first tower of the Highland Towers apartment complex in Selangor, Malaysia fell, ultimately killing 48 people. The cause of failure was attributed to a landslide that occurred due to pipes that burst, allowing for the barren ground near the… Read More »