Objective The first objective of this lab was to determine if the coarse aggregate meets ASTM C33 standards for coarse aggregates. Also this lab was used to determine the specific gravities of the coarse aggregate. Lastly, this lab helped to determine if this coarse aggregate could be used to make a good gravel driveway.

Apparatus and Materials 1. Ohaus Heavy Duty Solution Balance, model 1119, property of Bluefield State College. 2. Common sieves: 1 – ½”, 1”, ¾”, #4, #8, including the pan and lid. 3. Peerless Stove and Mfg. Co. oven, #2324DS (Solitest model L-90), property of Bluefield State College. 4. Common gravel aggregate. 5. Common flask. 6. “Bath Scale”, BSC # 18589.

Method
Sieve Analysis:

This lab exercise determined the size of coarse aggregate as it passed through the given sieves resulting in a percent that passed though, and a percent that was isolated on the sieves.

Gravel coarse aggregate was obtained and weighed using the Ohaus HD Solution Balance and approximately 1 kg of the gravel aggregate was measured. Sieves were obtained then stacked according to sieve size, from largest screen openings to finest, with the pan on the bottom. The 1kg of coarse aggregate was then poured over the top sieve and the lid was placed on top. The stack of sieves was then shaken by hand to sift the aggregate over the layers of sieves. The lid was removed and the coarse aggregate on each sieve was weighed and the weight was recorded on the Coarse Aggregate Lab. Data Sheet.

#200 Wash Test

This lab exercise consisted of weighing the coarse aggregate and then washing it though a #200 sieve to determine how coarse of an aggregate could be obtained by determining how much would pass through a #200 sieve. Approximately 1 kg of oven-dried coarse aggregate was weighed and recorded on the Coarse Aggregate Lab. Data Sheet. The gravel was then placed on a #200 sieve and rinsed with water until the water was clear that ran out the sieve. The coarse aggregate was then dried and weighed again, and it was recorded on the Coarse Aggregate Lab. Data Sheet.

Specific Gravity
This test determined the specific gravity of the coarse aggregate.
Oven dried gravel was saturated with water and allowed to oven dry to give a saturated surface-dried weight. 2kg of SSD gravel was obtained and was recorded on the Coarse Aggregate Lab. Data Sheet. The gravel was then submerged in a bowl of water and the weight of the 2kg of gravel that was submerged was obtained and recorded. The gravel was then removed and placed in an empty bowl of known weight and allowed to oven dry for at least 24 hours, the final oven-dried weight of the gravel is recorded on the Coarse Aggregate Lab. Data Sheet.

Results
The Coarse Aggregate Lab. Data Sheet contains the numerical data of all three of the aforementioned tests. The Aggregate Grading Chart 1 contains the data obtained in the sieve analysis plotted by sieve # vs. total percent passing.
The bulk specific gravity of the coarse aggregate was = 2.66.
The apparent specific gravity of the coarse sand aggregate was = 2.73.
The % absorption was = 0.92%.
The uniformity coefficient = 2.46.

Discussion
First in response to whether this would make a good aggregate for a gravel driveway, it appears that it would.
Next, in response to whether or not the aggregate met the requirements in C33 of the ASTM for coarse aggregates, it does not due to the condition that it retains more material on the #4 sieve than any one sieve and it meets the requirements in C33 Table 2.
Problems encountered during the lab exercise resulted in either miscalculation of weights or human error in loss of aggregate in regards to the sieve analysis.

Conclusions
The use of this lab experiment to determine factors such as specific densities and practical applications such as gravel were very conclusive. The data shows that this does not meet the ASTM C33 requirements for a coarse aggregate. This course aggregate would meet the gravel size #56 and #67.

Recommendations This lab could have been completed with greater care in 2 lab sessions.

Appendix

Cumulative % retained = % retained sieve 4 Cumulative % retained = % retained sieves 4+8 Cumulative % retained=% retained sieves 4+8+16, etc.
%Passing = 100-Cumulative percent retained sieve 4 %Passing=100-Cumulative percent retained sieve 4+8, etc.
Cu = D60 / D10 Sieve Size | Wt. of Agg (g) | % Retained | Cumm % | % Passing | ASTM C33 Specs | 1 ½ in | 0 | 0 | 0 | 100 | 100 | 1 in | 0 | 0 | 0 | 100 | 95-100 | ¾ in | 284.1 | 28.4 | 28.4 | 71.6 | 25-60 | ½ in | 162.7 | 16.3 | 44.7 | 55.3 | 0-10 | #4 | 552.7 | 55.3 | 100 | 0 | 0-5 | #8 | .5 | 0 | 100.5 | 0 | 0 |

References
Basic Construction Materials, 7th Edition, by Theodore W. Marotta.