One possible error that could have affected our results was not filling the water in the volumetric flask to the calibration line due to parallax, in which the water line was read at various angles instead of directly level with the flask. Possible errors that might have occurred during the test were a result from human error. The percentage could be more accurately defined by running more tests to reduce the amount of plausible error. The absorption percentage is significant and a useful quality for aggregate because higher values can indicate non-durable aggregate. However, the absorption percentage was determined to be 0.208%, which was acceptable. The specific gravity was 2.503, which is in the range by Portland Concrete Association (PCA). The test for Specific Gravity of Fine Aggregate using the specifications required by ASTM C128-07 determined that the sample of FA would be applicable for concrete design. 1 are located in Appendix A, and the example calculations are shown in Appendix B. The raw data made on the lab handouts for Test No. The procedure was conducted according to the stated procedure by the laboratory handout. The sample was put into an oven and dried overnight, and then the mass of the oven-dried FA was recorded. After the masses were recorded, the aggregate was emptied into a small pan to be dried to a constant mass. Water was then added back to the calibration line and the mass of the water, FA, and volumetric flask were recorded. Also, a paper towel was used to damp the surface of the mixture to assist in removing air bubbles. Additional water was added to agitate the mixture until the air bubbles were removed. The mixture of FA and water was created, which can be seen in Figure 3-1. Then water was poured out of the flask to a small quantity to create space for approximately 500g of the SSD aggregate to be added. The mass of the filled volumetric flask was recorded. A large volumetric flask was cleaned and then filled with water up to the calibration line. The FA maintained a slight slump, which indicated SSD conditions were achieved, and can be observed in Figure 2-1. Any excess FA around the base of the cone was removed, and then the cone was carefully removed by lifting vertically. After the cone was filled and the excess scraped off the top, the sample of fine aggregate was lightly tamped into the cone with 25 drops using a tamping rod starting approximately 5mm above the top surface of the sample. As shown in figure 1-1, the cone is held securely as it is being filled and to allow additional material to be placed above the top of the cone. The small tin pan was used to ensure a smooth nonabsorbent surface and to catch the overflow of fin aggregate. A cone was placed inside a small tin pan with the large diameter down. A sample of dry fine aggregate was soaked for 24 hours and then oven-dried at a rate of 110C by the lab instructor prior to the start of the laboratory experiment. 1 – Specific Gravity of Fine Aggregate, may be found on the laboratory handouts in Appendix A in the report and in ASTM C128-07. The apparatus consisted of a small cone, tamping rod, volumetric flask, and an oven.įigure 2-1 The FA Sample achieved SSD Conditions with Slump The sample of aggregate was obtained from a storage bin in the Henry Morrison Laboratory at Boise State University. The specimen used for this part of the laboratory consisted of dry fine aggregate. 1 was to determine the Bulk Specific Gravity, Bulk Specific Gravity – Saturated Surface Dry (SSD), and the Absorption of Fine Aggregate based on the test procedures outlined in ASTM C128-07. Table 1-1 Determined Calculations for Uncompacted Voids 6 3 – Sieve Analysis for Fine Aggregates 8ĪPPENDIX A – Laboratory Handouts and Raw Data 14įigure 2-1 The FA Sample achieved SSD Conditions with Slump 2įigure 4-1 Fine Aggregate Angularity (FAA) Testing Apparatus5įigure 5-1 Sieve Stack in Mechanical Shaker8įigure 6-1 Mechanical Analysis Graph (Grain Size Distribution Curve)10 Each of the lab tests had minimal error and followed the outlined procedures by ASTM requirements, and had outputted successful results. The results of the data for each of the three tests conclude that the sample of the fine aggregate would be applicable and recommended for concrete design according to Portland Cement Association (PCA) and ASTM standards. The data results for are test are listed below: The test procedures and equipment followed specifications by the American Society for Testing and Materials (ASTM), ASTM C128-07, ASTM C1252-06, and ASTM C33-08. The laboratory consisted of three tests that were to determine the Specific Gravity, Absorption, and particle size distribution by Sieve Analysis of Fine Aggregates, that are used in concrete design.
0 Comments
Leave a Reply. |