Test Results
Ready to pass the toughest test: Yours.
Rigorous laboratory testing has affirmed a number of CarbonCast performance characteristics. Below is a sample of tests that demonstrate its suitability for a variety of applications. Contact your AltusGroup precaster for more information and complete test reports.
- Tests of Composite Precast Sandwich Panels Reinforced with MeC-GRID for Shear and Flexure
- Insulated Wall Panel Tests – Hybrid Wall Panels
- Insulated Wall Panel Tests – Fully Prestressed Panel, Non-Load Bearing
- Transfer of Connection Moments in Composite Load Bearing Insulated Wall Panels (Demonstration Test)
- Behavior of Altus Wall Panels Part I: Tests of 20’ EPS Panels
- Cyclic Testing of CarbonCast Insulated Sandwich Wall Panels Part II
Tests of Composite Precast Sandwich Panels Reinforced with MeC-GRID for Shear and Flexure
The objectives of this test program were to 1) determine the shear and flexural strengths of the panel, 2) determine in-plane compression strength for concentrated loads, and 3) determine the load/deflection relationships for the panels. Two identical 4’ x 8’ insulated sandwich panels were fabricated. Both wythes were reinforced with C-GRID in the wythes and C-GRID shear grid was used to connect the wythes through the foam. The panels were subjected to axial, out-of-plane, or both loadings. It was found that both the axial behavior and flexural behavior were predictable using conventional analysis procedures. A lower bound to the shear strength was determined at 1.97 kips per rail. Additional testing is needed to determine design values of the shear strength.
Insulated Wall Panel Tests – Hybrid Wall Panels
The objectives of this test program were to 1) evaluate the performance of a prestressed hybrid panel subjected to vertical and out-of-plane loads and compare predicted performance with experimental results, 2) develop an understanding of the flexural and shear behavior of hybrid panels, 3) optimize panel design, and 4) develop design methods. One 10” x 12’ x 40’ prestressed hybrid panel with a C-GRID reinforced exterior wythe and equally spaced prestressed concrete ribs incorporated into the interior wythe was fabricated and tested. C-GRID shear grids were used to provide composite action between the two wythes.
The panels were tested in the vertical position with an axial load applied to the top of the panel and cyclic out-of-plane loadings applied in 4-point bending. The testing indicated that the non-composite interior wythe containing ribs is adequate for strength and the composite panel is adequate for serviceability. In addition, the panel behaved in a linear elastic manner for loadings exceeding the factored wind load.
The objectives of this test program were to 1) evaluate the performance of a prestressed hybrid panel subjected to vertical and out-of-plane loads and compare predicted performance with experimental results, 2) develop an understanding of the flexural and shear behavior of hybrid panels, 3) optimize panel design, and 4) develop design methods. One 7” x 10’ x 30’ hybrid panel with a C-GRID reinforced exterior wythe and equally spaced steel reinforced concrete ribs incorporated into the interior wythe was fabricated and tested. C-GRID shear grids were used to provide composite action between the two wythes.
The panels were tested in the vertical position with cyclic out-of-plane loadings applied in 4-point bending. The panel exhibited considerable ductility and carried load well in excess of the factored load. The behavior was non-linear even at fairly low loads; however, the deflections were well within an acceptable range. It was found that the interior wythe containing ribs was adequate for strength if compression reinforcement was considered, otherwise the rib spacing would need to be reduced. The composite panel was adequate for serviceability.
Insulated Wall Panel Tests – Fully Prestressed Panel, Non-Load Bearing
The objective of this test program was to evaluate the performance of a fully prestressed composite insulated wall panel with C-GRID for shear transfer when the panel is subjected to 1) vertical and horizontal loads, 2) repeated loads, and 3) sustained loads. A further objective was to determine if theoretical models of shear performance match experimental results. One 8” x 8’ x 36’ insulated wall panel was fabricated and tested. Both wythes were prestressed with 6-⅜” strands.
The panel was tested in the vertical position with out-of-plane loadings applied in 4-point bending. The panel was subjected to cyclic loadings representing 50% of the unfactored wind load, sustained loads for one hour representing 100% of the unfactored wind load, and cyclic loading to failure. For the repeated loading, some inelastic behavior was observed, but there was no significant change in the deflection pattern with each cycle of loading indicating that the panel was stable and not deteriorating. For the sustained loading, the unfactored wind load applied for one hour in each direction increased the instantaneous deflection by about 15% in the outward direction and a negligible amount in the inward direction. For the failure load tests, the panel carried a load exceeding the factored wind load exhibiting fairly ductile failure behavior.
Transfer of Connection Moments in Composite Load Bearing Insulated Wall Panels (Demonstration Test)
The purpose of the test reported here is to demonstrate a test protocol to evaluate different connection designs and to suggest a design procedure for transferring connection moments to composite panels. The panel was first loaded with the load eccentricity set at 3 inches. The load was increased to 46 kips with no observable effect on the test panel. At this point the flange of the loading beam started to buckle and the load was removed. The eccentricity was increased to 4.75 inches and the load increased to 41 kips. At this point the shear grid began to fail as evidenced by slippage between the foam and the inside wythe. The outside wythe was cracked horizontally completely through its’ thickness at a point corresponding to the bottom of the embed plate. In addition there was some evidence of cracking and spalling around the embed plate.
Behavior of Altus Wall Panels Part I: Tests of 20’ EPS Panels
The report summarizes the results of tests of two identical prestressed concrete sandwich wall panels that used EPS as an insulation material and C-GRID™ carbon fiber grid shear connectors. Panels were tested in a vertical configuration to enable the application of both vertical and horizontal loads. Both panels were subjected to nearly 4000 cycles of reverse cyclic fatigue at 45% of the factored lateral load with the gravity load in place. Following the fatigue regime, lateral loads on the panels were increased to failure. In general, the panels exhibited elastic behavior up to their factored loads and failed at 1.8 times and 2.8 time the service loads corresponding to 150 mph and 120 mph wind speeds.
Cyclic Testing of CarbonCast Insulated Sandwich Wall Panels Part II
Report is currently being written for panels insulated with XPS foam.
