CONSTRUCTION

Problem Solving

Construction

The following examples illustrate some of our contributions to this business sector:

• Prior to completion of the construction of a public building the anodized aluminum window frames developed what appeared to be white stains. Examination found that the white areas were actually places where the anodizing had been removed, apparently by chemical action of water leaching material from the masonry. Samples of the aluminum frames and the various materials used in construction were tested, and it was found that a decorative white brick was releasing caustic lime when water ran over the surface. This caustic leachate dissolved the coating from the widow frames.
• Touchstone, working with two suppliers, developed a coil-coated, painted/galvanized steel product used for the sides and roof of metal buildings. This product has become the top selling agricultural building system sold in the United States.
• A sprocket and teeth, which were broken from a sprocket, were delivered to Touchstone Research for examination. The fracture surface was heavily oxidized. Metallographic examination of a “good” tooth cut from the sprocket and the failed tooth revealed that both exhibited cracking at the root of the teeth. Investigation of the sprocket production system was recommended since cracks can be formed during casting or forging procedures by several mechanisms including cold shuts, misruns, cold cracks, and/or forge laps.
• Touchstone has performed analysis lubricating oil samples to determine whether glycol based antifreeze ws present.
• A problem with carpeting removal during the remodeling of a hotel was presented to Touchstone. Attempts at removal of old carpet met with considerable difficulty. The answer was found by examining video instructions on installation and comparing the instructions to the condition of carpeting samples removed from the structure. It was found that an improper practice had been followed when the carpet was installed where the foam padding underlayment had been securely bonded to the concrete floors. The design practice called for a low strength bond to the concrete decking to allow easy removal.
• Cut nails are appealing when used for fastening outdoor, decktreated floorboards because of their head configuration. They also provide superior-holding power compared to wire nails. Staining from corrosion, however, especially in marine environments, prevents the use of carbon steel cut nails. Touchstone, compared the performance of several grades of stainless steel nails and selected the grade most suitable for this application. The investigation included holding power tests and both accelerated and longterm exposure testing. Today, this new stainless-steel cut nails enjoy a large market share.
• Shortly after installation, wood paneling was seen to loosen and fall away from the cast concrete walls in a building. Analysis of the paneling found that the bond had separated at the wood/adhesive interface. GCMS analysis of extracts from the paneling found an oil present that prevented good bond strength between the wood and the adhesive.
• A steel company was considering the purchase of a plant, which manufactures steel studs for the construction industry. Prior to the purchase, Touchstone performed testing of the studs for mechanical properties and a coating evaluation.

The above examples are only a sample of our work in this area. We would be pleased to provide any additional information you may require. We also invite you to review examples on our website of work that we have performed in support of other business sectors.