trabajo de conccreto grupo 2.pdf

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UNIVERSIDAD SAN IGNACIO DE LOYOLA

FACULTAD DE INGENIERÍA Y ARQUITECTURA

Curso:

TECNOLOGÍA DEL CONCRETO I

bloque:

FC-SMVINGICV05A1T

Tema:

DESIGN OF CONCRETE

Profesor:

SOTOMAYOR CRUZ, CRISTIAN DANIELElaborado por:

CAMPOS LUPUCHE, GERALDINE GLADYS

DONGO GONZALES, MERLY ROSARIO

LAURA CASTILLO, CARLOS HENRY

PACHECO GOMEZ, FRANDIO

PAJUELO BEDON, GEREMIAS MARCOS PEREZ HERRERA, OLIVER

PUMACAHUA MAMANI, OSVEL RAUL

Lima-Perú

2015



Introduction

Concrete is the building material most widely used today. However, although thefinal quality depends very significantly both a deep knowledge of the material andthe professional quality engineer, general concrete is largely unknown in many

aspects (nature, material, properties, the ratios selection , process put in work ,quality control and inspection, and treatment of structural elements).

That is why the process of determining the required characteristics of concreteand that can be specified is very important to get a concrete that meets all thenecessary qualities.

Las características del diseño de mezcla de concreto pueden influir enpropiedades del concreto fresco(Workability,Consistency SlumpLoss,Segregation/Bleeding, Plastic Shrinkage,Time of Set,Temperature),propiedades mecánicas del concreto endurecido(densidad, compacidad,contracción, compresión) y la inclusión, exclusión o límites de ingredientesespecíficos.

It is important to establish the rates at which must intervene the materialsintegrant for concrete to meet the technical requirements on work, make thetheoretical calculation for dosage of materials is very important because of thatdepends the characteristic of concrete ,and finally the designed concreteshould be prepared in the lab and make some corrections as needed to yoursuitable employment in work.



Theoretical framework

Previous concepts

Concrete: a composite aggregates, water and additives in special cases it isalso the most common material used in construction.

Aggregates: they are inert materials mixed with cement to form concrete, areclassified into two fine aggregates (sand) and coarse aggregate (stonecrushed), according to ASTM specifications.

Water: It is the most important in the preparation of the mixture, which shouldbe used in appropriate amount material, and provides resistance workability inhardened concrete, much or less; It is recommended if the mixture is dry,

instead of adding water drop additive. Additive provides specific special features to improve their properties. .

Consistency of concrete: The test for consistency or slump also called "Slumptest" is used to characterize the behavior of concrete in fresh state, this testdeveloped by Duft Abrams, adopted in 1921 by the ASTM.

CONSISTENCY ASPECT SLUMP WORKABILITYCOMPACTION

METHOD

DRY loose andcohesionless 0''- 2'' little workable

powerful

vibrationcompacted inthin layers

PLASTIC slightly cohesive 3''- 4'' workablenormal

vibration

SOFT slightly fluid >5'' very workableslight

vibration andvatillado

Table 1..Types of mixtures according to their settlement



Particle size: evaluation of size, shape and texture of the aggregates, alsocharacterize it according to the requirements of the work. It also helps you getthe maximum nominal aggregate size and fineness modulus.

Specific gravity (γ) is the relationship between weight and volume of the

material thereof.Moisture content (W) moisture content within the aggregate, is expressed inpercentage.

Absorption (a): the amount of water you need to spend an aggregate drycondition to the condition of saturated surface and is expressed in percentage.

Ratio water and cementIt: It is the main factor of concrete strength.

Design considerations for the mixture

The particular dosage is based on data obtained in the laboratory and theinformation provided by the teacher, and the use of materials and tools for thisdesign, therefore the design of the mixture is taken into account:

Sieve analysis of fine and coarse aggregate according to the data.



Specific gravity of materials: cement, water and aggregate

Rates of absorption and aggregate moisture

Type and brand of cement, in this case Type I cement was used, brand

Sol

Mixing water requirements based on experience with the aggregates.

Relationship between strength and water-cement ratio for the possible

combinations of cement and aggregates.

Considerations of air content in this case was incorporated air content and

cement and other materials.

Slump test analysis

The method used for the mix design: It used method ratio water and

cement.

Keywords: mix design, concrete slump test, cement, aggregates, water andadditives.

Materials

Cement

coarse aggregate (crushed stone)

Fine aggregate (sand)

Water



Superplasticizer admixture

Instruments

Digital Scale

Retractable tape measure

Mason trowels

Abrams cone

Smooth steel rod tipped bullet 5/8 ''

Cylindrical mold

Plate

Rubber hammer Mixer

Wheelbarrow

Sieving machine

FINE AGGREGATE

COARSE AGGREGATE

ADMIXTURE

PORTLAND

CEMENT



MIXER BUCKET

WINCHA DIGITAL BALANCE

WHEELBARROW

RUBBER HAMMER



CONE ABRAMS

SMOOTH

STEEL BAR

MASON

TROWELS

CYLINDRICAL MOLD

PLAQUE

RUBBER

HAMMER

SIEVING MACHINE



CALCULATION OF THE MATERIALS TO MIX:

DATA

F´c=280 kg/cm2 slump = 6”-7” huso 57 TMN= 1” Cement Type 1 Sand/stone =52/48 Aire incorporado = 4%

1. Calculating the weight and volume of water.We calculate the weight of the water with the slump and maximum size

= 184 = 184

=

=184

1000 /

= 0,184

2. We calculate the water-cement ratio in the table below: We proceed to interpolate:

300 − 280

300 − 250=

0,45 −

0,45 − 0,52

= 0,478 = /



3. We calculate the weight and volume of cement.

=

/=

184

0,478= 384,94

=384,94

3150 /= 0,122

4. We calculate the weight and volume of the additive

= 0,01 × = 0,01 × 384,94 = 3,8494

=

= 3,8494 1170 / = 0,00329

5. calculate the remaining volume (volume aggregates)

= 1 − ( 0,00329 + 0,122 + 0,184 + 0.04)

= 0,65071

6. calculate weight and volume of the aggregates

+ = 0,65071 :

=

52

48

= 0,53 × (0,65071) = 0,3384

= 0,3384

× (2700/

) = 913,68

= 0,48 × (0,65071) = 0,3123

= 0,3123 × (2600/) = 811,98

7. We calculate the absorption and moisture of the aggregates

absorption of the aggregate fine = 0,87

absorption of the aggregate coarse = 0,60



8. correct weights of inputs by m3

INSUMOS PESOS KG

VOLUMEN

m3/m3 Water absorption kg water moisture fixed weights kg

WATER 184.0000 0.184

184-8.6288+12.8209=

188.1921

CEMENT 384.9400 0.122 384.9400

ADDITIVE 3.8494 0.00329 3.8494

AIR 0.0000 0.04 0.0000

STONE 811.9800 0.3123 811.98x0.60/100=4.8719 811.98x0.15/100=1.2180 811.98+1.2180=813.198

SAND 913.6800 0.3384 913.68x0.87/100=7.9490 913.68x0.81/100=7.4008 913.68+7.4008=921.0808

TOTAL 2298.4494 1 12.8209 8.6288 2311.2603

the slump was 7.80 “

sand + tara (damp) 0,124 kg

sand + tara (dry) 0,123 kg

tara 0.014 kg

% H (0,124-0,123)X100/0,123

% H sand 0,81

stone + tara (damp) 0,650kg

stone + tara (dry) 0,649 kg

tara 0.503 kg

% H (0,650-0,649)X100/0,649

% H stone 0,15

We work with 2% of 2311.2603 kg

INSUMOS x2% kgWATER 188.1921x2% 3.763842

CEMENT 384.94x2% 7.6988

ADDITIVE 3.8494x2% 0.076988

AIR 0 0

STONE 813.198x2% 16.26396

SAND 921.0808x2% 18.421616

TOTAL 46.225206



Materials

1. Water

2. Cement type I

3. Plasticizer additive



4. Coarse aggregate 5. fine aggregate



Experimental Procedure

1. Divide your materials in correct proportion according to the mixed design

2. Start the mixer.

3. Add about half the fine aggregate.4. Carefully add all the cement with the mixer running. Try not to make a lot

of dust!5. Mix until all the cement is blended in.6. Add the rest of the coarse and fine aggregate.7. Mix for a while.8. Add enough water from the final quarter of the water to produce a

workable mix.9. Mix for three minutes, followed by a three-minute rest, followed by a two-

minute final mixing.



10. Perform a slump test using the procedure given below. If results aresatisfactory.

Slump Tests

WORKABILITY is the relative ease or difficulty of placing and consolidating

concrete. When placed, all concrete should be as stiff as possible, yetmaintain a homogeneous, and void less mass. Too much stiffness, however,makes it too difficult or impossible to work the concrete into the forms andaround reinforcing steel. On the other hand, too fluid a mixture is alsodetrimental. The slump test is performed on newly mixed concrete. To performthe test, you need a slump cone and a tamping rod. The slump cone (fig. 3.1),12 in. in height, with a base opening 6 in. Both the top and bottom openingsare perpendicular to the vertical axis of the cone.

Cylindrical plastic molds are used to cast the concrete specimens. The moldsshould be filled in three approximately equal layers. Each layer should beridded (poked with a bullet nosed steel rod) 25 times to eliminate unwantedair bubbles. The top of the molds should be struck off with the rod and thenwith a wooden float.

Once the specimens have been struck off, the outside of the molds should becleaned as well as the mixer and tools. Fresh concrete is a lot easier to cleanthan when it has set. The cylinders should now be placed in the lab fog roomfor curing. After 24 hours a member of your group must strip off the mold andcarefully mark your specimen with your group number. If the slump is lessthan required, return the concrete to the mixer, add the remaining water, andmix for one minute



NTERPRETATION OF RESULTSDesign data:Specifically: fc = 280 kg / m2Cement type: ISlump: 6-7

Air content: 4%% Sand-stone: 52-480.01% plasticizing additiveTime: 5-7TMN: 1 "Known data per m3:Water volume: 0.184 m3W / c ratio: 0.478Cement Weight: 384.94Cement volume: 0.122 m3 Additive Weight: 3.8494 kg

Additive Density: 1170 kg / m3 Additive Volume: 0.00329 m3Remnant Volume: 0.65071Volume of the sand: 0.3384 m3Stone Volume: 0.3123 m3Sand weight: 913.68 kgStone Weight: 811.98 kgObtained data (Worked with 2% of design m3)Water: 3.763842 kgCement: 7.6988 kg Additives: 0.077 kg Air: 0 kgStone: 16,264 kg Arena: 18.4216 kgW / c ratio: 0.478Fine aggregate Humidity%: 0.81% Absorption% fine aggregate: 0.37 After making the necessary calculations and the desired results you have to:When testing the cone of Abram, the Slump was 7.8 in. this means that themixture is workable but, while being less dense concrete tends to be lessresistant. Furthermore, this test allows us to determine if the mixture is

complying with the design of concrete required or desired. As the moisture content is greater absorption, this means that the excess wateris added and is providing water to the mixture, so that water has to besubtracted to the mixture. Knowing the water content of aggregates is importantin designing mixtures to adjust the amount of water to be added or removedwater to the mixture.Readjustment moisture which is conducted into the arena because it presenteda humidity of 0.81% and was 0.37 absorption. In doing all this procedurecorrected data are: cement weight 7.6988 kg / m3, water weight was 3.5958 kg,for sand weight was 18.4216 kg, for stone weight was 16,264 kg and finallyweight 0.077 kg additive.

The water cement ratio is a function that asks us to design (resistance tocompression) that is the most important mechanical property of concrete.



The settlement is considered in some methods as input data, while another isselected from a table, based on the structural member such that the nextintended design mixture.The concrete must support those exposures that may deprive it of its ability toservice such as freezing and thawing, repeated cycles of wetting and drying,

heating and cooling, due to these factors is incorporated air.Mix concrete of fc = 280kg / cm2 meets design.is added to the concrete 0,030 gk of additive and 300 ml of water.



CONCLUSION

He designed for a resistance of 280 kg/m2 the following factors were born inmind:

a. THE RELATION WATERS DOWN I CEMENT: that is the principal factor thatinfluences the resistance of the concrete one. The relation a/c affects theresistance to the compression of the concrete one with or without airincorporated in our case it was with built-in air

b. THE CEMENT CONTENT: the resistance diminishes as the cement quantitystoops

c. THE TYPE OF CEMENT: in the test there was used the type of cement Io

that has a frequent use in the construction

d. THE CONDITIONS OF TREATED: provided that the relations of cementhydration only happen with the presence of a suitable quantity of water, it isnecessary to to support the dampness in the concrete one during the period oftreated.

e. HUSO 57: maximum nominal size 1 "

In the test of accession of the concrete one was observed a decrease of 7pulg. And a severe partial back down of the concrete one (it indicates that the

quantity d thin and thick attaché they have similar proportion)The quality of the attachés (the gradation) has a direct influence in the

resistance of the concrete one.

The maximum size of the thick attaché influences the resistance of theconcrete one.

The determinations of the free unit weights are important since with thesevalues they are with which one is employed at work.

The morphology of the attachés influences in the properties of the concrete one

in fresh and hard condition, with a major influence in the workability that in themechanical properties. It is for it that must bear in mind the quality and origin ofthe attaché supporting it with a certain quantity of temperature and dampness.

The thick attaché was containing harmful particles as organic matters.

The water used for the mixture was a drinkable water.

To the equal one the sand was containing organic substances for the concreteone.

trabajo de conccreto grupo 2.pdf

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