Application Technical Note: Pinholes & Bugholes This Technical Note does not address the loss of aggregate at the time of form removal. Rock pockets, form seams and other such discontinuities are beyond the scope of this Technical Note. Simple outgassing of concrete, covered in pinhole resolution, is beyond the scope of this Technical Note. PROBLEM:…
VF 20™ Application Techniques for Concrete Substrates 1. Prior to application of VF-20 primer insure that all concrete surfaces are prepared to SSPC SP13/NACE No. 6, Surface Preparation of Concrete standard. 2. Concrete and masonry surfaces must be dry. Moisture content of concrete surface to be less than 5.0% when tested with a Tramex Concrete…
Displaced Fine Particulates Technical Note: DFP – Displaced Fine Particulates Since the introduction of coal fly ash into many of the new concrete mix designs, fine particulates are troweled into the surface where they have the probability of being displaced from the concrete. This is especially evident when any adhesive type material is applied to…
“How to Minimize Shrinkage” Originally published in Concrete Contractor Written by: Kim Basham, PhD PE Drying shrinkage is the root cause of random cracking in unreinforced concrete floors. Drying shrinkage is caused by a loss of moisture from the concrete. It occurs after concrete hardens and continues months and even years depending on the slab…
Polyurea Life Expectancy Discussion A question has recently been asked as to the life expectancy of a polyurea spray elastomer system as it relates to an application in an immersed saltwater environment. While this question is really not new to the technology, it seems that there has not been any published data or information to…
QUV Weatherometer Testing: (ASTM G 53) QUV Weatherometer accelerated testing (ASTM G 53) has been used as a tool to evaluate the performance of polyurea spray elastomer systems. By using this technique, one can observe the physical affects of simulated sunlight on the surface properties of the exposed elastomer as well as physical property retention.…
FSS 45DC™: Direct Food Contact Certification Coating Extraction Tests SAMPLE DESCRIPTION: The Client submitted a cured black polyurea coating identified as FSS 45DC™. REQUEST: Determine compliance of the coating to 21CFR 175.300 for contact with nonacid aqueous food products, under high temperature heat-sterilized use conditions. METHOD: The sample was subjected to the extraction test outlined in…