Summary: | Large-scale slake durability index tests have been performed on Khok Kruat (KK), Phu Kradung (PK) and Phra Wihan(PW) sandstone. A rotating drum with a diameter of 64 cm and length of 40 cm was fabricated to accommodate ten rockfragments with a nominal size of 10 cm. Both large-scale and standard-testing were performed under dry and wet conditions.The large-scale test yields rock deterioration twice greater than the small-scale test, primarily due to the greater energyimposed on the rock fragments. The weight losses under wet condition are 12%, 8%, and 3% greater than under dry condition for KK, PK, and PW sandstones, respectively. After 10 test cycles the water absorption values for PW, KK and PKsandstones are 12%, 3%, and 2%, respectively. Rock degradation under the rapid cooling-heating cycles in the laboratory isabout 18 times faster than under the field condition in the northeast of Thailand.
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