Explore: Physical Characteristics

Critical variables are discussed that occur in the culture and testing of Cladocerans that are responsible for the failure to obtain acceptable results in interlaboratory comparisons. The variables in question include diet, ambient medium, health of the test species, characteristics and purity of the compounds tested, and, finally, whether nominal or measured concentrations are utilized to estimate the results of static acute toxicity tests. Available data indicate that diet, ambient medium, health of the test organism, and the physical and chemical characteristics of the test compound and how the latter is measured seriously affects the comparability of the results of round-robin tests.

Critical variables are discussed that occur in the culture and testing of Cladocerans that are responsible for the failure to obtain acceptable results in interlaboratory comparisons. The variables in question include diet, ambient medium, health of the test species, characteristics and purity of the compounds tested, and, finally, whether nominal or measured concentrations are utilized to estimate the results of static acute toxicity tests. Available data indicate that diet, ambient medium, health of the test organism, and the physical and chemical characteristics of the test compound and how the latter is measured seriously affects the comparability of the results of round-robin tests.

This paper investigates the potential of crushed tiles as coarse aggregate in concrete. Test results of bulk, saturated surface dry (SSD) and apparent specific gravities, bulk unit weight, water absorption, resistance to abrasion, percent of voids and grading (performed as per ASTM standards) on two types of crushed tiles were compared with the results of conventional crushed stone aggregate. Also included are results from tests on concrete cylinders under uniaxial compression, split tension, and beams under flexure to determine the influence of variables of test age on concrete strength, type of tiles, and ratio of volume of crushed tile to the total volume of coarse aggregate in concrete. Recommendations for use of crushed tile as coarse aggregates in concrete are given.

This paper investigates the potential of crushed tiles as coarse aggregate in concrete. Test results of bulk, saturated surface dry (SSD) and apparent specific gravities, bulk unit weight, water absorption, resistance to abrasion, percent of voids and grading (performed as per ASTM standards) on two types of crushed tiles were compared with the results of conventional crushed stone aggregate. Also included are results from tests on concrete cylinders under uniaxial compression, split tension, and beams under flexure to determine the influence of variables of test age on concrete strength, type of tiles, and ratio of volume of crushed tile to the total volume of coarse aggregate in concrete. Recommendations for use of crushed tile as coarse aggregates in concrete are given.