Basic properties of lightweight composites

Consistency of the fresh mix:Each mixture was prepared twice to confirm the repeatability of the results. After mixing and gelation of the paste, the consistency of the fresh mixture was measured twice in accordance with EN 1015-3:2000. The prepared fresh cement mortar was placed in a truncated-cone mold positioned at the center of the flow table. The mortar was gently compacted by light tamping in accordance with the standard procedure. After 15 seconds, the mold was carefully lifted vertically. The table was then raised and dropped 15 times from the standard height, causing the mortar to spread. The diameter of the resulting mortar pat was measured in two perpendicular directions.Settlement of the mix (sedimentation):One of the issues observed during the experimental work was water bleeding from the fresh gelled cement paste, as shown in Figure 3. Therefore, for each mixture, the extent of this phenomenon was assessed. To this end, the final height of 10 cm cubic specimens was measured. Their height should be roughly 100 mm; however, in some composites where this issue was evident, the height is smaller. For each mixture, two specimens were measured.Volume density test:Volume density was tested on specimens dried to constant mass at 70°C. The specimens were rectangular prisms with dimensions of approximately 45×100×100 mm. For each mixture, four specimens were measured. Mean values and standard deviations of the measurements were calculated. Specimen masses were weighed in grams to two decimal places. Dimensions were measured in millimeters to two decimal places.