Architectural preferences for commercial building continue towards increased transparency resulting in large lites of glass with minimal visual obstruction. Point fixed glazing systems meeting this architectural desire are popular especially in entry or common areas at ground level. Recent technology advances have allowed the use of super high strength adhesives to attach these large lites to fittings without the requirement of drilling through glass.
The typical ground floor location increases the probability that the system must function as a protective layer for occupants of the building above and beyond the typical code required exposures such as wind loading. Some blast performance testing has been published on drilled point fixing systems but not on the adhesive method.
The purpose of this paper is to document mock-up testing using a shock tube with an explosive charge to simulate blast loads onto adhesively bonding transparent assemblies. The variables include pre-defined blast loads from ASTM F2912-17 performed on lites laminated with SGP ionomer interlayer.
The study, a first of its kind, enables the ability to quantify potential blast performance for use in large scale testing and building design. Four 2.36” diameter TSSA fittings were attached to lites 60” x 60”. Four assemblies loaded to 7 psi or less showed no breakage or effect on TSSA and glazing. Five assemblies were loaded above 9 psi, and four of the five showed glass breakage resulting in glazing displaced from the opening. In all cases, TSSA remained attached to the metal fittings and no failure, adhesive or cohesive, was noted. The testing shows that this tested TSSA design is capable of an effective safe system, according to AAMA 510-14, at loads of 7 psi or less. The data generated here can be used for engineering the system of TSSA to meet specified loads.
Structural silicone attachment of glass panels has been used for nearly 50 years to enhance the aesthetics and performance of modern architecture (Hilliard, 1977; Zarghamee, 1996, Carbary 2007, Schmidt, 1989
Frames were fabricated from American Standard Steel Channels of dimension 6” x 1.92” x 0.20” web thickness commonly referred to as a C 6” x 8.2# channel. The C Channels
As mentioned above four frame assemblies were tested till the glass was removed from the opening from the blast.
The first test was targeted to reach 10 psi A 89 psi-msec
This study was undertaken to determine if adhesive attachment of glazing systems has some sort of inherent danger or flaw in low level specified blast performance requirements. It is clearly
Hilliard, J. R., Parise, C. J., and Peterson, C. O., Jr., Structural Sealant Glazing, Sealant Technology in Glazing Systems, ASTM STP 638, ASTM International, West Conshohocken, PA, 1977, pp. 67–99.
Zarghamee, M. S., Schwartz, T. A., and Gladstone, M., “Seismic Behavior of Structural Silicone Glazing,” Science and Technology of Building Seals, Sealants, Glazing and Waterproofing, Vol. 6, ASTM STP 1286, J. C. Myers, Ed., ASTM International, West Conshohocken, PA, 1996, pp. 46–59.
Carbary, L. D., A Review of the Durability and Performance of Silicone Structural Glazing Systems, Glass Performance Days, Tampere Finland, June 2007 conference proceedings pp. 190-193
Schmidt, C. M., Schoenherr, W. J., Carbary L. D., and Takish, M. S., “Performance Properties of Silicone Structural Adhesives,” Science and Technology of Glazing Systems, ASTM STP1054, C. J. Parise, Ed., American Society for Testing and Materials, Philadelphia 1989, pp. 22-45
Wolf, A.T, Sitte, S., Brasseur, M., J., and Carbary L. D, “Preliminary Evaluation of the Mechanical Properties and Durability of Transparent Structural Silicone Adhesive (TSSA) for Point-Fixing in Glazing” Fourth International Symposium on Durability of Building and Construction Sealants and Adhesives, Journal of ASTM International, published online August 2011, Volume 8, Issue 10 (November 2011), JAI 104084, available at www.astm.org/DIGITAL_LIBRARY/JOURNALS/JAI/PAGES/JAI104084.htm.
Clift, C., Hutley, P., Carbary, L.D., Transparent Structural Silicone Adhesive, Glass Performance Days, Tampere, Finland, June 2011, conference proceedings pp. 650-653
Clift, C., Carbary, L.D., Hutley, P., Kimberlain, J., “Next Generation Structural Silicone Glazing” Journal of Facade Design and Engineering 2 (2014) 137–161, DOI 10.3233/FDE-150020
Kenneth Yarosh, Andreas T. Wolf, and Sigurd Sitte “Evaluation of Silicone Sealants at High Movement Rates Relevant to Bomb Mitigating Window and Curtainwall Design” Journal of ASTM International, Vol. 6, No. 2 Paper ID JAI101953
Morgan, T., Advances in Explosion Resistant Bolt Fixed Glazing, Glass Performance Days, June 2103, Conference proceedings pp 181-182
Wedding, William Chad, and Braden T. Lusk. "Novel method to determine blast resistant glazing system response to explosive loading." Measurement 45.6 (2012): 1471-1479.