Acid-Freeze Thaw

  1. Acid Freeze-Thaw Accelerated Aging by Wiss, Janney, Elstner Associates, Inc. Reference WJE Report No. 2005.2577 dated 26 September 2006
    Flexural strength tests in accordance with ASTM C880 procedure and Tensile bond tests in general accordance with ASTM D897 procedure were conducted on both new and 19-year old StoneLite® specimens to measure strength, durability and performance characteristics. Tests were conducted on current production of Rosa Porrino granite, Indiana limestone, plus both new Roman Classic travertine and Roman Classic travertine that had been installed on the exterior of a building in the Chicago, IL area 19 years ago. The accelerated weathering consisted of exposing specimens to a cyclic temperature from -10 F to +170 F for 100 cycles while partially submerged in a 4-pH sulfuric acid solution to simulate acid rain. After 100 cycles of exposure StoneLite® granite lost 2.7% of ultimate load flexural strength, limestone lost 6.3%, new travertine lost 4.7%, and old travertine lost 3.7%. The strength of new travertine and 19-year old travertine was similar in the longitudinal orientation although the old travertine had lower strength in the transverse orientation. Tensile bond strength tests were not conclusive because most of the specimen failure was due to internal fracturing of the stone while the bond to honeycomb did not fail.
  2. Test on Freeze-Thaw and Flexure Testing. Reference SwRI Report No. 04-6751-124/141 dated 31 March 1995
    White Carrara marble, Indiana limestone, Roman Classic travertine and Black Impala granite StoneLite® panels were subjected to an accelerated aging procedure of temperature cycling 100 times from +170 F to -10 F while the stone face, bond line and honeycomb were submerged in a 4-pH sulfuric acid solution. The exposed specimen and corresponding control samples were then subjected to one-quarter-point flexure loading, placing the stone and bond line in tension. There was no bond failure, which would have been considered possible due to the shear stress between the stone and the honeycomb. The StoneLite® panel flexure strength loss averaged only 13%, as compared with a loss of flexural strength in solid dimensional stones of 25% to 70% of their original strength. Wiss Janney Elstner Associates Engineers followed this testing with both accelerated aging and flexural tests.
  3. Test method developed in Europe, conducted by PARTEK in Finland. Reference PARTEK Report MATLAB 33/96 dated 15 Nov. 1996
    StoneLite® White Carrara marble panels were subjected to 200 cycles of 4 pH acid rain, UV radiation exposure, and temperature variation from -30 C (-22 F) and 25 C (77 F). There was an average of less than 6% reduction in bond strength following the 200 cycles of exposure. As a result of this testing and two (2) years of additional investigation, the technical committee for Finlandia Hall in Helsinki approved the StoneLite® panel system for replacement of solid 4 cm dimensional stone slabs that had warped with many having fallen from the exterior walls.
  4. Freezing & thawing in water in accordance with ASTM C-67. Reference Ramtech Laboratories Report No. 8098A-87
    StoneLite® panels were exposed to 100 cycles of freezing at 0 F for 20 hours, followed by thawing in water at a temperature of 75 F for 4 hours, then repeating the freezing and thawing procedure immersed in water. The average flatwise tension bond capacity was 290 psi (41,760-lbs per sq. ft.) following the 100 cycle test.
  5. Flatwise Tensile Strength Tests Performed on Limestone Panels in Accordance with ICBO Standard AC05 and ASTM C297. Ref. Terrapin Testing Inc. Project 50427.
    Testing began with a 25 cycle, freeze-thaw exposure process on five of each type of limestone, Indiana and Stanton Moore. Each cycle as follows:(2) Hours @ -40°F;(2) Hours @ 70°F;(2) Hours @ 160°F;(1) Hour @ 0°F. Stress at failure for each Limestone was greater than 300 psi.
  6. Shear and flatwise tension bond tests were conducted in accordance with ICBO Test Standard AC05 for the purpose of evaluating the bonding adhesive. Reference Columbia Research & Testing Report ESR No. 99136.
    Shear and flatwise tension bond tests were conducted after StoneLite® panels had been subjected to accelerated aging by submerging in water 48 hours, drying at 145 F for eight hours, followed by three cycles of soaking 16 hours and drying 8 hours. After aging, the average shear capacity increased from 914 psi to 948 psi (136,512 lbs. per sq. ft.), and the average flatwise tension capacity also increased from 309 psi to 337 psi (48,528 lbs. per sq. ft.)