Abstract: With properties significantly different from quartz sand of land origin, the calcareous sand of marine origin has irregular in grain shape, fragile and porous with both inter-connected and inner pores. Due to the inner porosity of the calcareous sand, the tested specific gravity values might be slightly different from different testing methods. Three different specific gravity testing methods: Pycnometer Method, Suspended Weighing Method and AccuPycII 1340 True Density Meter Method, are used to test the specific gravity values of both calcareous sand and quartz sand samples. The results are also evaluated. The “true density” values and the inner porosity of calcareous sand samples were tested by the AccuPycII 134 True Density Meter before and after the grain grinding. The results indicate that the tested specific gravity values were different with different testing methods. Smaller differences on values tested by Pycnometer Method and True Density Meter Method, comparing with the values tested by Suspended Weighing Method and True Density Meter Method. The inner porosity values on different grain size samples are different. A specific gravity value of 2.81 is suggested for the calcareous sand samples. From the testing time, testing accuracy and easiness points of view, AccuPycII 1340 True Density Meter Method is appropriate for the specific gravity testing on calcareous sand samples with various grain sizes.

Key words: calcareous sand, specific gravity, AccuPyc Ⅱ 1340 true density meter, pycnometer method, suspended weighing method