UNIVERSIDAD SAN IGNACIO DE LOYOLA TECNOLOGA DEL CONCRETO ITECNOLOGA DEL CONCRETO I

PROFESORA: SOTIL CHAVEZ, ANDRES INTEGRANTE: TORRES JULIAN, CHAIN EFRAIN HUAMAN SEDANO, PERCY

Lima-Per2015

Title Sieve Granulometry for Fine and Coarse AggregatesAuthorsNoelia Miranda Aguire, Kevin Davila Mamani, Marco Catacora Postigo. San Ignacio de Loyola University. La Molina. October 2nd, 2013.

Executive SummaryThe experience of laboratory N1 entitled Sive Granulometry for Fine and Coarse Aggregates took place at the National University of Engineering. This laboratory basically consisted in finding the gradation of fine and coarse aggregates. First of all, fine aggregates were separated from the coarse aggregates, both materials were separated in four equal parts, and only choose two of these parts, and then the aggregates were sieved in order to know the weight retained on each sieve.According to procedures performed and learned in this lab N1, we have the conclusion that knowing the gradation of aggregates is very important because they are the principal component of concrete and we have to be really careful.

IntroductionAggregates have an important role in the preparation of concrete. The aggregates occupy 70-75% of concrete volume, so its quality is of great importance.Aggregates may affect some concrete properties as strength, structural performance, durability, and economy; therefore, sieve granulometry is so important to know the gradation of fine and coarse aggregates and determine the proportion that will have these in the mix to make concrete.Procedure

We arrived to the UNI and we got the required equipment.We entered to the lab and we had a short talk about the uses of it. Then, we started to recognize the material that we were going to use.On the one hand we had coarse aggregates and on the other hand we had fine aggregates.Both aggregates were separate in four equal parts and choose only two pieces, and then with the same parts, we separated in four equal parts again and choose two. In addition, we proceeded to sieve each aggregate separately.

Finally, we weigh the aggregate in each mesh to find the retained weight. As shown in Figure 2.

Figure 2.Summary:We have doing some test of materials. We have fine aggregate and coarse aggregate, for both we found their gradations. First, we have to mix the material and separated it in four equal parts, and only choose two of these parts. This process we have to doing for each aggregate, and then we have to find the weight and complete the gradation table for each one.

Experimental Data

Table 1: Course aggregatesThe weight of the sample = 5 kg = 5000 grMaximum size = 1 Nominal size = SieveWeight ret (gr)% RetCumulative ret (%)% Pass

11963.9233.92396.077

228345.69749.62050.380

204540.93390.5529.448

3/83156.30596.8573.143

1192.38299.2390.761

PAN380.761100.0000.000

Total4996

We noticed that there were some loss on the weight of the sample and in percentage is: 5000-4996 = 4(4/5000)*100 = 0.08%The maximum lost that we will have is 1%, but we have 0.08%, so this result is acceptable.To do our gradation table of coarse aggregate, we have the next data.

Table 2: Fine aggregateThe weight of the sample = 500 grMaximum size = 3/8Nominal size = N8

SieveWeight ret (gr)% RetComulative Ret (%)% Pass

N416.53.68293.682996.3171

N87615.452419.135380.8647

N1611617.954437.089762.9103

N3011818.654955.744644.2554

N508621.537277.281822.7182

N1005014.972092.25387.7462

PAN357.74621000

Total497.5

We noticed that there were some loss on the weight of the sample and in percentage is: 500-497.5= 2.5(2.5/500)*100 = 0.5%The maximum lost that we will have is 1%, but we have 0.5%, so this result is acceptable.

Analysis of Results

Calculating % Retained in table N1

%Ret = (Weight ret / Total)*100

For 1: % Ret = (196/ 5000)*100= 3.92% For : % Ret = (2283/ 5000)*100= 45.69% For : % Ret = (2045/ 5000)*100= 40.93% For 3/8: % Ret = (315/ 5000)*100= 6.31% For 1/4: % Ret = (119/ 5000)*100= 2.38% PAN: % Ret = (38/ 5000)*100= 0.76%

Calculating % Retained in table N2

%Ret = (Weight ret / Total)*100

For N4: % Ret = (16.5/ 5000)*100= 3.68% For N8: % Ret = (76/ 5000)*100= 15.45% For N16: % Ret = (116/ 5000)*100= 17.95% For 3/8: % Ret = (118/ 5000)*100= 18.65% For 1/4: % Ret = (86/ 5000)*100= 21.54% For 1/4: % Ret = (50/ 5000)*100= 14.97% PAN: % Ret = (35/ 5000)*100= 7.75%

Answering of Questions

To do our gradation table of coarse aggregate, we have the next data.Sieve% Pass

196.077

50.380

9.448

3/83.143

0.761

Pan0.000

And to find the fineness modulus of coarse aggregate we use the next equation.F.M = { (cumulative % Retained on 1 . , 3/8, N4, 8,16,30,50 and 100 sieves)}/100F.M= 49.62+96.83+6x100F.M = (746.45)/100) = 7.46Fine aggregate:To do our gradation table of coarse aggregate, we have the next data.Sieve% Pass

N496.3171

N880.8647

N1662.9103

N3044.2554

N5022.7182

N1007.7462

Pan0

And to find the fineness modulus of coarse aggregate we use the next equation.F.M = { (cumulative % Retained on N4, 8,16,30,50 and 100 sieves)}/100F.M = (3.68 + 19.14 + 37.09 + 55.74 +77.28 +92.25)/100F.M = 285.18/100= 2.85Questions

2) Do the fine aggregates meet the ASTM specifications (ASTM C33) for fineness modulus? That is, being between 2.3 and 3.1The fineness modulus of the fine aggregate is:F.M = { (cumulative % Retained on N4, 8,16,30,50 and 100 sieves)}/100F.M = (3.6829 + 19.1353 + 37.0897 + 55.7446 + 77.2818 + 92.2538)/100F.M = 2.851881 = 2.85This F.M is between 2.3 and 3.1: 2.3 < 2.85 < 3.1So this aggregate is good for used in the mix of concrete.

SPECIFIC ABSORPTION AND PERCENTAGE OF ADDED WEIGHTFINE AGREGGATE:Weight dry sand surface500gr

Weight superficially dry sand + weight + water weight ball950.8gr

Weight ball140.7gr

Wter weight (W)310.1gr

Weight of dry sand in the oven (A)493.4gr

Balloon volume (V) 500ml

SPECIFIC GRAVITY OF MASS = 2.60gr SPECIFIC WEIGHT DRY SAND SURFACE= 2.63gr Apparent specific weight = 2.70gr Absorption rate = 1.337%COARSE AGREGGATE:weight of the oven dried sample

2970

saturate sample weight saturated surface dry3000gr

weight is water saturated sample weight + cage2570gr

Wter weight (W)310.1gr

cage weight8.72gr

saturated sample weight in water1907ml

Resolution:

specific weight of dough500gr

SPECIFIC WEIGHT DRY SAND SURFACE2.74gr

Apparent specific weight3.87gr

Absorption rate1.01%

Conclusions and Recommendations

As a conclusion, we were able to learn about different process we need to do with our materials in order to design a better concrete for our construction.Water in our material is an important part to take care when we design our concrete. It could increase or decrease the percent of water in our mix, so its very important for us to know that amount of water because it could let our concrete lose strength or get unworkable.There are so many tests we need to do with our materials in order to get a better concrete, so its very important for engineers to know about this part of our career.

Referenceshttp://www.astm.org/ ASTM International Standards Worldwide. Web page that has the international standards norms for engineers.

http://www.engineerlive.com/content/22142 Web Page that has a lot of information about granulometry process. http://www.pavementinteractive.org/article/los-angeles-abrasion/ Web page that provides information of the L.A Abrasion Test.