n MTS 858 tabletop servo-hydraulic loading system was used to test the cylindrical and the 0.05m cube samples. The load cell was mounted below the fixed base and the displacement transducer (LVDT) traveled with the actuator, maintaining the supporting cross head as reference. A 25mm gauge extensometer was attached to the middle section of cylindrical samples to record localized deformations.  The extensometer was mounted on the specimens with a set of two rubber bands (Photo3-1). Strain controlled tests were performed at 10% strain per minute.

An Instron Model 1335 servo-hydraulic loading system was used to test the 0.6m cubes. Special large area loading platens were connected to the top and bottom loading fixtures of the machine to apply pressure over the top and base surfaces of the test specimens (Photo 3-2). Eight channels were used to retrieve the test data. One channel was used for the load cell and the remaining seven were used for displacement transducers. Five of the transducers were used to monitor vertical displacement. Vertical deformations of the total sample as well as at the upper and lower third positions along the corner and center of the sample face were monitored. In some tests, vertical deformation at 0.025m below the top platen and at 0.050m above the base as well as along the top and bottom third of a block side were monitored. Two of the displacement transducers were used to monitor horizontal movement at the middle of opposing sides of the block. All of the reported tests were strain controlled at the same strain rate of 10 percent per min as for the small samples tested in the MTS system.

A large high capacity Young mechanical loading frame was used to test a stack of four 0.6m height specimens (Photos 3-3 and 3-4). The test was done at a constant displacement rate of 48mm per min and strain rate of 2%per min. Eight channels were used to collect the test data. One channel was for the load cell and seven channels were used for displacement measurements. Seven displacement transducers were positioned to monitor the deformation of the entire stack as well as to isolate gauge segments across blocks and within one block. Small foam brackets were attached to the 0.6m blocks using non-shrink EPS compatible glue. The bracket contacts were left to harden for 24 hours before being used for localized displacement monitoring over the height of the blocks.

Photo 3‑1 The MTS Machine

Photo 3‑2 The Instron Machine

Photo 3‑3 The Young Machine

Photo 3‑4 Mounting the LVDTs on the Foam Specimens