# Concrete Mix Design Using Particle Packing Method

Download Concrete Mix Design Using Particle Packing Method

## Preview text

International Journal of Informatics Information System and Computer Engineering 2(1) (2021) 83-102 83 | International Journal of Informatics Information System and Computer Engineering 2(1) (2021) 83-102

International Journal of Informatics, Information System and Computer

Engineering

Concrete Mix Design Using Particle Packing Method: Literature Review, Analysis, and Computation

Shreya Sunil Tolmatti*, Sanskruti Jaywant Jadhav**, Sakshi Satish Jadhav***, Mayur M. Maske**** Rajarambapu Institute of Technology, India E-mail: *[email protected]

A B S T R A C T S

Particle packing technology is used to reduce the amount of cement in concrete by optimizing the concrete mix, resulting in more sustainable concrete. In this study, four different methods were used to determine the distribution of the mixture presented; packing density method, packing density method, IS code method, and packing density method. The purpose of this study is to explain literature review, analysis, and data computation of the concrete mix design using particle packing method. In the packing density method, the paste content that exceeds the voids will increase along with the increase in the quality of the concrete. In cases of packing density, the cement-water ratio decreases with the quality of the concrete. In the packing of too many trials, trials and tribulations should be carried out to achieve the ratio of water-cement and paste content for a certain grade of concrete. This correlation curve helps reduce the experiments involved in determining the ratio of semen and paste content for a given concrete quality. The water and cement contents for the packing density and the IS code method are almost the same for each particular concrete class. The workability of concrete achieved was more in the packing density method than the IS code method for the same concrete quality, because the water-cement ratio was slightly higher in the packing density method than the IS code method. Therefore, more water and cement are required in terms of packing density. The correlation curve can be used to determine the ratio of water-cement and paste the content that exceeds the voids for a certain concrete quality.

ARTICLE INFO

Article History: Received 18 May 2021 Revised 20 May 2021 Accepted 25 May 2021 Available online 26 June 2021

___________________

Keywords: Concrete Mix Design, Mixtures Presented, Packing Density Method, Is Code Method

Tolmatti et al. Concrete Mix Design Using Particle …| 84

1. INTRODUCTION

There are various methods of proportioning for various types of concrete. The packing density method of mix design is the only mix design method used for proportioning normal concrete, high strength concrete, no-fines concrete, and self-compacting concrete (Raj et al., 2014).

The subject of optimizing the concrete composition by selecting the right amounts of various particles has already used interest for more than a century. To optimize the particle packing density of concrete, the particles should be selected to fill up the voids between large particles with smaller particles and so on, to obtain a dense and stiff particle structure. Most of the early researchers, working on the packing of aggregates, proposed methods to design an ideal particle size distribution. Geometrically based particle packing models can help to predict the water demand of concrete, and thus the material properties.

The cement paste has to fill up the voids between aggregate particles and the “excess” paste will then disperse the aggregate particles to produce a thin coating of paste surrounding each aggregate for lubricating the concrete mix. In general, the higher the packing density of the aggregate, the smaller will be the volume of voids to be filled and the larger will be the amount of paste in excess of void for lubrication (Yang et al., 2020).

The purpose of this study is to explain literature review, analysis, and data computation of the concrete mix design using particle packing method. In IS code method of mix design, we have curves to decide the water-cement ratio

whereas in the packing density method we don’t have such type of co-relation curves available. Here an attempt has been made to develop co-relation curves between compressive strength of concrete versus water-cement ratio and paste content versus Compressive strength. These co-relation curves help to reduce the trials and decide the watercement ratio and paste content for the given grade of concrete.

Packing density is a new kind of mix design method used to design different types of concrete (Glavind, M., & Pedersen, E. 1999). To optimize the particle packing density of concrete, the particles should be selected to fill up the voids between large particles with smaller particles and so on, to obtain a dense and stiff particle structure. The higher degree of particle packing leads to minimum voids, maximum density, and requirement of cement and water will be less. In this work, the co-relation curves are developed for the packing density method between compression strength and water-cement ratio, paste content to reduce the time involved in the trial to decide water-cement ratio, and paste content for a particular grade of concrete (Rao, V. K., & Krishnamoothy, S. 1993).

An important property of multiparticle systems is the packing density. This is defined as the volume fraction of the system occupied by solids. For a given population of grains, it is well known that the packing density (Powers, 1968).

The packing density of the aggregate mixture is defined as the solid volume in a unit total volume (Hettiarachchi, C., & Mampearachchi, W. K. 2020). The aim of obtaining packing density is to combine aggregate particles to minimize the

85 | International Journal of Informatics Information System and Computer Engineering 2(1) (2021) 83-102

porosity, which allows the use of the least possible amount of binder (see Fig. 1).

always increase the packing densities of ordinary Portland cement and pulverized fly ash, the addition of a polycarboxylatebased superplasticizer could decrease the packing density of condensed silica fume.

Fig. 1. Prediction of particle packing density

(Source: http://link.springer.com/ accessed on 04/04/2021)

2. LITERATURE REVIEW

Wong and Kwan used the ordinary

Portland cement complying with BS

12:1996. Fennis and Walraven used

ordinary Portland cement and blast

furnace slag cement. Wong and Kwan

used aggregate particles smaller than

1.2mm for mortar and aggregate particles

larger than 1.2mm for concrete mix.

Kwan and Wong used pulverized fly ash

as cementations material complying with

BS 3892: Part 1: 1982. Kwan and Wong

used the condensed silica fume

complying with ASTM C 1240-03 as the

cementation’s material in their

experiments. Kwan and Wong in their

studies used two types of

superplasticizers a polycarboxylate-

based and cross-linked polymer and

naphthalene-based

formaldehyde

condensate

1. Kwan and Wong measured the packing densities of cementations materials containing ordinary Portland cement, pulverized fly ash, and condensed silica fume. The results for non-blended materials revealed that the addition of a superplasticizer would

2. Kwan and Wong proposed a three-tier system design. The mix design would be divided into three stages. At the first stage, the packing density of the cementitious materials would determine the water demand, and at the second stage the aggregate particles smaller than 1.2mm would determine the paste demand and at the third stage, the aggregate particles larger than 1.2mm would determine the mortar demand.

3. Kwan and Wong used the minislump cone test to check the fresh state properties in their experimental studies. Fennis and Walraven carried out centrifugal consolidation to check the workability. Kwan and Wong obtained a curve between voids ratio and watercement ratio for cementitious materials, where the ordinary Portland cement is blended with the pulverized fuel ash and condensed silica fume in different proportions.

From the above study, it is observed that the packing density mix design method is used to minimize voids to increase particle packing and to reduce the binder content.

3. METHOD

Ordinary

Portland

cement

conforming to IS 12269-1987 locally

available river sand belonging to zone II

of IS 383-1970was used. The locally

available crushed aggregate of size 12.5

mm and 20 mm downsize conforming to

IS 383-1970 were used in the preparation

of concrete. Potable water was used in the

Tolmatti et al. Concrete Mix Design Using Particle …| 86

present investigation for both casting and curing of the concrete. Superplasticizer complies with IS 9103:1999 Sulphonated Napthelene based polymers are used. Bulk density and specific gravity test were carried out as per IS 2386(Part III)1963 and the test results are presented in Table 1.

4. RESULTS AND DISCUSSION

4.1. Design of Concrete Mix Using Packing Density Method

1. Determination of aggregate fractions

The packing density of the aggregate mixture is defined as the solid volume in a unit total volume. The aim of obtaining packing density is to combine aggregate particles to minimize the porosity, which allows the use of the least possible amount of binder. Two size fractions of coarse aggregates were selected for the study i.e., 20 and 12.5 mm down a size. The values of bulk density of the coarse aggregates (20 and 12.5 mm in size) were first determined separately.

The coarse aggregate 20 and 12.5 mm were mixed in different proportions by mass, such as 90:10, 80:20, 70:30, and 60:40, etc., and the bulk density of each mixture is determined. The addition of a smaller size aggregate (12.5 mm downsize) increases the bulk density. However, a stage is reached when the bulk density of the coarse aggregate mixture, which instead of increasing, decreases again. The results of the Bulk density of coarse aggregate fractions (20 mm and 12.5 mm) are plotted in Fig. 1.

aggregate or overall aggregate is determined from its maximum bulk density of the mixture and specific gravity. Therefore, the total packing density of the mixture is the sum of the packing density of 20 mm, 12.5 mm, and fine aggregate i.e., equal to the ratio of bulk density of mixture to the specific gravity of individual aggregate (20 mm: 12.5 mm: fine aggregate). The value of specific gravity should be taken as average if the values are differing in the third decimal and if the values are differing in the second decimal, the individual values should be taken for calculating packing density and voids content.

3. Determination of Voids Contents and Voids ratio

The voids content in percentage volume of aggregate or mixture of three aggregate is determined from its bulk density.

From Figures 2, 3, and 4, it is observed that the bulk density, packing density are maximum and voids ratio is minimum for 70 % of coarse aggregate (20 mm) and 30 % of coarse aggregate (12.5 mm) respectively.

2. Determination of Packing Density

The packing density of individual aggregate in a volume fraction of total

Fig. 2. maximum bulk density for 20 and 12.5 mm aggregates

87 | International Journal of Informatics Information System and Computer Engineering 2(1) (2021) 83-102

density, and voids ratio are plotted against the mass fraction of coarse aggregate are presented in Figures 5, 6, and 7, respectively. From Figures 5, 6, and 7, the maximum bulk density is 2.007 gm/cc, the maximum packing density is 0.722 gm/cc, and the minimum voids content is 0.2866.

Fig. 3. maximum packing density for 20 and 12.5 mm aggregate

Fig. 5. Maximum bulk density for 20 mm and 12.5 mm and fine aggregates

Fig. 4. minimum voids ratio for 20 and 12.5 mm aggregates

An increase in fine aggregate

particles leads to a decrease in void

content thus increases the bulk density.

The replacement of fine aggregates in the

total coarse aggregates (20 and 12.5 mm

downsize in the proportion of 70:30) in

the ratio of 90:10, 80:20, 70:30, 60:40, and

55:45. By increasing the finer content the

bulk density increases up to a maximum

extent after which it again reduces. Thus,

the proportion obtained for maximum

bulk density is fixed as total coarse

aggregates: fine aggregates i.e., 60:40.

Total coarse aggregate proportion i.e., 20

mm:12.5 mm is fixed as 70:30 as

mentioned

earlier.

Therefore,

proportions of these aggregates i.e.,

coarse aggregates 20 mm: coarse

aggregates 12.5 mm: fine aggregates are

42:18:40. The bulk density, packing

Fig. 6. Maximum packing density for 20 mm and 12.5 mm and fine aggregate

Fig. 7. Minimum voids for 20 mm, 12.5 mm and fine aggregate

Tolmatti et al. Concrete Mix Design Using Particle …| 88

Using the above concept, design of concrete mix is carried out for M20, M25, M30, M35 and M40 concrete mixes. A detailed sample calculation for M20 grade of concrete is presented below. The ingredients of concrete for M20 grade were obtained for 5%, 10% and 15% in excess of paste content and water-cement ratio 0.56 and 0.58 the values are presented in Table 2.

4.2. Mix Design for M20 Grade Concrete (Packing Density Method)

The calculations are presented in the following paragraph for bulk density, voids ratio and packing density.

1. Bulk density of combined coarse aggregate 20 and 12.5 mm in the proportion 70:30.

W2- W1 Bulk density =

Volume of mould

Where,

W1= empty weight of mould

W2= weight of mould + aggregate filled

Bulk density (Maximum) 35066-9800

= 15000

= 1.6840 gm / cm3

2. Bulk density of three aggregates i.e., CA 20mm : CA 12.5mm : FA is 42 : 18 : 40. (coarse aggregate 20 mm : 12.5 mm i.e., 70 : 30 as fixed earlier).

Bulk density (Maximum) 39916-9800

= 15000

= 2.0077 gm / cm3

3. Voids content:

Voids content in percent volume 2.8143-2.0077

= 2.8143 x 100 = 28.660%

4. Packing density (P.D.):

Packing density (maximum) Bulk density x weight fraction

= Specific gravity

Packing density of 20mm aggregates 2.00778x0.420

= 2.9122 = 0.2896 gm/cm3

Packing density of 12.5 mm aggregates 2.0078x0.180

= 2.9376 = 0.1230 gm/cm3

Packing density of fine aggregates 2.00778x0.400

= 2.5931 = 0.3097 gm/cm3

Total Packing Density = Packing Density of CA (20 mm) + Packing Density of CA (12.5 mm) + Packing Density of Fine Aggregate.

PD = 0.7223 gm / cm³

This packing density value is fixed for further calculations. 4.3. Determination of Paste content for

M20 Grade Concrete

89 | International Journal of Informatics Information System and Computer Engineering 2(1) (2021) 83-102

Minimum paste content is the sum of the void content in combined aggregate and excess paste over and above it to coat the aggregate particle. The meaning of minimum paste content can be explained as, a concrete mix containing minimum paste content should be cohesive, free from segregation and bleeding. Flow table tests were carried out to decide the minimum paste contents required to form the workable mix for different W/C ratios and different paste content in excess of void content.

Voids content = 1 – 0.7223 = 0.2777

Assuming paste content as 10% more than void content, detailed calculations to obtain all. Ingredients of concrete such as coarse aggregate 20 mm, 12.5 mm, fine aggregate, cement, and water content are given below.

Paste content 10% more than void content

Paste content = 0.2777 + 0.1x 0.2777

= 0.3054

Volume of aggregates = 1 – 0.3054

= 0.6945 cc

Total solid volume of aggregates

Weight fraction of 20 mm = Specific gravity +

Weight fraction of 12.5 mm Specific gravity +

Weight fraction of fine aggregate Specific gravity

Total solid volume of aggregates

0.420 0.180 0.400 = 2.9122 + 2.9376 + 2.5931

= 0.3598 cc

Weight of 20 mm aggregates

0.6945 = 0.3598 x 0.420 x 1000=810.7354 kg/cum

Weight of 12.5 mm aggregates

0.6945 = 0.3598 x 0.180 x 1000=347.4580 kg/cum

Weight of fine aggregates

0.6945 = 0.3598 x 0.400 x 1000=722.1290 kg/cum

For M20 grade concrete keeping in mind the target mean strength suitable water-cement ratio is fixed as per trial mixes.

W/C ratio = 0.56; W = 0.56C.

C 0.56C Total Paste=C+W= 3.15 + 1 =0.8775 C

0.3054 Cement content= 0.8775 x 1000

=348.1140 kg/cum Water content = 0.56 x 348.1140

= 194.9438 Kg/cum Following the above procedure, all the ingredients of concrete were obtained for 5%, 10%, and 15% in excess of paste content and water-cement ratio 0.56 and 0.58, the values are presented in Table 2.

To decide the paste content and water cement ratio among three paste content and two water cement ratios, using the above ingredients Flow Table tests were carried out. Flow Table test is carried out as per IS 1199-1959 (Indian Standard). Results of Flow table tests for M20 grade concrete indicated that water cement ratio 0.58 and all the three-paste content (i.e., 5%, 10% and 15 %) and water cement

Tolmatti et al. Concrete Mix Design Using Particle …| 90

ratio 0.56 with 5% paste content were rejected because of segregation and bleeding. Water cement ratio 0.56 with paste content of 10% and 15% in excess of void content resulted in good flow percent of 133 and 134 respectively without segregation and bleeding. For water cement ratio 0.56 in order to decide the paste content i.e., 10% and 15% in excess of void content, trial cube casting was carried out for 7 days cube compressive strength.

The average compressive strength (3 cubes) obtained at the end of 7 days curing was 22.88 N/mm and 23.666 N/mm for 10% and 15% paste content respectively. Keeping economy in mind paste content of 10% for water-cement ratio 0.56 was finalized for further casting. Mix design is carried for M25, M30, M35, and M40 grade concrete as mentioned in mix design steps for M20 grade concrete. The value of packing density remains the same irrespective of the grade of concrete because coarse aggregate 20 mm, 12.5 mm and fine aggregate used is the same for all grades of concrete. Depending on the grade of concrete paste content will vary, increases with an increase in grade of concrete. The Water-cement ratio for different grades of concrete (M25, M30, M35, and M40) is fixed as per trial mixes. Paste contents for different grades of concrete were determined using flow table tests as mentioned earlier for an individual grade of concrete finalized mix proportions are presented in Table 3.

4.4. Design of Concrete Mix Using IS Code Method

Mix design is also carried out using IS code 10262-2009 (Indian Standard). The objective of IS code method of mix design is to compare the ingredients of concrete (mix proportions) with the packing

density method and also to compare the compressive strength at 28 days in these two cases and relevant observations were discussed. Here also the final mix proportions were obtained for M20, M25, M30, M35, and M40 grade of concrete using IS method with the different trial mixes. The trial mix design for different grades of concrete was carried for different water-cement ratios and workability is checked using Flow Table tests. Accepted trial mixes were further used to cast the trial cube specimens and were tested for compressive strength at the 7 days curing age. Observing the results of trial casting the appropriate mix is finalized. This finalized mix proportion is used for further casting. Finalized mix proportions for different grades of concrete designed by IS code method are presented in Table 4.

4.5. Comparing the Mix Proportion of Concrete by IS Code Method and Particle Packing Method

1. Mix Proportions and Compressive Strength

Finalized mix proportions for M20, M25, M30, M35, and M40 grade concrete using packing density and IS code method are presented in the following tables. Using these finalized mix proportions for different grades of concrete final casting was carried out as mentioned in the following section.

In the packing density method, finalized mix proportions were used for final casting. Six cube specimens were cast (3 cube specimens for 7 days curing and 3 cube specimens for 28 days curing). Similarly, in IS method for each grade of concrete six cube specimens were cast (3 cube specimens for 7 days curing and 3 cube specimens for 28 days curing). The casting, curing, and compressive strength testing procedure was followed

91 | International Journal of Informatics Information System and Computer Engineering 2(1) (2021) 83-102

according to IS 516-1959 (see Figs. 8 and 9).

The average test result of 3 cube specimens is considered for the final test result. The results of the final casting are presented (Tables 5 and 6).

2. Workability

The variation in workability of concrete mixes designed by different methods with different water-cement ratios is presented in table 7 (KORE, S. D., & Vyas, A. K. 2017).

It can be seen from table 7, all the concrete mixes achieved their target slump of 75-100 mm. While achieving the target slump the dose of the superplasticizer is increased. In the case of the packing density method at all watercement ratios, the dose of superplasticizer required is more than that of the BIS code method. This increase is caused by the increased sand content in concrete mixes designed by the packing density method as seen in Table. On average sand, content increased by 14% in the packing density method as compared to that of the BIS code method. The increased sand content absorbs more water from the mix resulted in a stiff mix. Hence, a higher dose of super-plasticizers is required to achieve the desired workability.

3. Saving in cement content and cost comparison

Table 8 saving in cement content (KORE, S. D., & Vyas, A. K. 2017).

Table 9 shows the saving in cement content in concrete mixes designed by the packing method. From this table, it was observed that the concrete mixes designed by the packing density method are economical because of saving in cement content. The maximum saving of

18% was achieved at a 0.45 water-cement ratio. The concrete mixes designed by the packing density method showed an average 12% reduction in cement content as compared to that of the BIS code method. It depicts that the concrete mixes designed by the packing density method are economical (KORE, S. D., & Vyas, A. K. 2017).

The table shows the cost analysis of the concrete mixes. From this analysis, it was observed that the concrete mixes designed by the packing density method show a saving in the material cost of concrete. The average cost of material to produce concrete can be reduced by 11% by adopting the packing density method for the design of concrete mixes. Hence it indicates that the concrete mixes designed by the packing density method are cost-effective and economical.

4. CO2 production

The cement manufacturing industry is a major contributor to CO2 emissions in the world. The contribution of the cement industry in greenhouse gas emission is around 3.95 billion tons annually and that is 7% of the total greenhouse gas emissions on the earth’s surface. The global annual production of concrete in the year 2014 was 4.2 billion tons and it is expected that this figure may increase by 2.9 % by 2018. In India, around 275 MT of cement was produced during the year 2014 which accounts for the generation of an equal amount of CO2. To produce 1 Ton of cement around 0.94 Ton of CO2 is released. The CO2 emission factor for road transport, i.e., trucks or lorries is considered as 512.2 g/km. Table 10 reduction in carbon di oxide emission.

Tolmatti et al. Concrete Mix Design Using Particle …| 92

Table 1. The technology used in the device of virtual voting system

Sl. No

1. 2.

3.

Materials

Fine aggregates Coarse aggregate 12.5 mm Coarse aggregate 20 mm

Bulk density Kg/m3

(Compacted condition) 1600.133 1387.777

1525.555

Bulk density Kg/m3 (Loose

condition) 1718.063 1542.222

1660.000

Specific gravity

2.593 2.937

2.912

Table 2. Trial mix proportions for M20 grade concrete

Grade of W/C concrete ratio

Excess paste content (%)

0.58 5

Water content (Kg/m3)

Cement content (Kg/m3)

188.4416 0.58

324.8994 1

Wt. Of Fine aggregate (Kg/m3)

787.6736

2.4243

Wt. Of 12 mm Coarse aggregate (Kg/m3)

354.4531

1.0817

0.58 10

197.4151 0.58

340.3708 1

772.2352 2.2688

347.5058 1.0209

0.58 15 M20

0.56 5

206.3885 0.58 186.0907 0.56

355.8422 1 332.3048 1

756.7967 2.1268 787.6736 2.3703

340.5585 0.9570 354.4531 1.0667

0.56 10

194.9522 0.56

348.1289 1

772.2352 2.2182

347.5058 0.9982

0.56 15

203.8136 0.56

363.9529 1

756.7967 2.0794

340.5585 0.9357

Wt. Of 20 mm Coarse aggregate (Kg/m3) 827.0573

2.5455

810.8469

2.3822

794.6366

2.2331

827.0573

2.4889

810.8469

2.3292

794.6366

2.1834

International Journal of Informatics, Information System and Computer

Engineering

Concrete Mix Design Using Particle Packing Method: Literature Review, Analysis, and Computation

Shreya Sunil Tolmatti*, Sanskruti Jaywant Jadhav**, Sakshi Satish Jadhav***, Mayur M. Maske**** Rajarambapu Institute of Technology, India E-mail: *[email protected]

A B S T R A C T S

Particle packing technology is used to reduce the amount of cement in concrete by optimizing the concrete mix, resulting in more sustainable concrete. In this study, four different methods were used to determine the distribution of the mixture presented; packing density method, packing density method, IS code method, and packing density method. The purpose of this study is to explain literature review, analysis, and data computation of the concrete mix design using particle packing method. In the packing density method, the paste content that exceeds the voids will increase along with the increase in the quality of the concrete. In cases of packing density, the cement-water ratio decreases with the quality of the concrete. In the packing of too many trials, trials and tribulations should be carried out to achieve the ratio of water-cement and paste content for a certain grade of concrete. This correlation curve helps reduce the experiments involved in determining the ratio of semen and paste content for a given concrete quality. The water and cement contents for the packing density and the IS code method are almost the same for each particular concrete class. The workability of concrete achieved was more in the packing density method than the IS code method for the same concrete quality, because the water-cement ratio was slightly higher in the packing density method than the IS code method. Therefore, more water and cement are required in terms of packing density. The correlation curve can be used to determine the ratio of water-cement and paste the content that exceeds the voids for a certain concrete quality.

ARTICLE INFO

Article History: Received 18 May 2021 Revised 20 May 2021 Accepted 25 May 2021 Available online 26 June 2021

___________________

Keywords: Concrete Mix Design, Mixtures Presented, Packing Density Method, Is Code Method

Tolmatti et al. Concrete Mix Design Using Particle …| 84

1. INTRODUCTION

There are various methods of proportioning for various types of concrete. The packing density method of mix design is the only mix design method used for proportioning normal concrete, high strength concrete, no-fines concrete, and self-compacting concrete (Raj et al., 2014).

The subject of optimizing the concrete composition by selecting the right amounts of various particles has already used interest for more than a century. To optimize the particle packing density of concrete, the particles should be selected to fill up the voids between large particles with smaller particles and so on, to obtain a dense and stiff particle structure. Most of the early researchers, working on the packing of aggregates, proposed methods to design an ideal particle size distribution. Geometrically based particle packing models can help to predict the water demand of concrete, and thus the material properties.

The cement paste has to fill up the voids between aggregate particles and the “excess” paste will then disperse the aggregate particles to produce a thin coating of paste surrounding each aggregate for lubricating the concrete mix. In general, the higher the packing density of the aggregate, the smaller will be the volume of voids to be filled and the larger will be the amount of paste in excess of void for lubrication (Yang et al., 2020).

The purpose of this study is to explain literature review, analysis, and data computation of the concrete mix design using particle packing method. In IS code method of mix design, we have curves to decide the water-cement ratio

whereas in the packing density method we don’t have such type of co-relation curves available. Here an attempt has been made to develop co-relation curves between compressive strength of concrete versus water-cement ratio and paste content versus Compressive strength. These co-relation curves help to reduce the trials and decide the watercement ratio and paste content for the given grade of concrete.

Packing density is a new kind of mix design method used to design different types of concrete (Glavind, M., & Pedersen, E. 1999). To optimize the particle packing density of concrete, the particles should be selected to fill up the voids between large particles with smaller particles and so on, to obtain a dense and stiff particle structure. The higher degree of particle packing leads to minimum voids, maximum density, and requirement of cement and water will be less. In this work, the co-relation curves are developed for the packing density method between compression strength and water-cement ratio, paste content to reduce the time involved in the trial to decide water-cement ratio, and paste content for a particular grade of concrete (Rao, V. K., & Krishnamoothy, S. 1993).

An important property of multiparticle systems is the packing density. This is defined as the volume fraction of the system occupied by solids. For a given population of grains, it is well known that the packing density (Powers, 1968).

The packing density of the aggregate mixture is defined as the solid volume in a unit total volume (Hettiarachchi, C., & Mampearachchi, W. K. 2020). The aim of obtaining packing density is to combine aggregate particles to minimize the

85 | International Journal of Informatics Information System and Computer Engineering 2(1) (2021) 83-102

porosity, which allows the use of the least possible amount of binder (see Fig. 1).

always increase the packing densities of ordinary Portland cement and pulverized fly ash, the addition of a polycarboxylatebased superplasticizer could decrease the packing density of condensed silica fume.

Fig. 1. Prediction of particle packing density

(Source: http://link.springer.com/ accessed on 04/04/2021)

2. LITERATURE REVIEW

Wong and Kwan used the ordinary

Portland cement complying with BS

12:1996. Fennis and Walraven used

ordinary Portland cement and blast

furnace slag cement. Wong and Kwan

used aggregate particles smaller than

1.2mm for mortar and aggregate particles

larger than 1.2mm for concrete mix.

Kwan and Wong used pulverized fly ash

as cementations material complying with

BS 3892: Part 1: 1982. Kwan and Wong

used the condensed silica fume

complying with ASTM C 1240-03 as the

cementation’s material in their

experiments. Kwan and Wong in their

studies used two types of

superplasticizers a polycarboxylate-

based and cross-linked polymer and

naphthalene-based

formaldehyde

condensate

1. Kwan and Wong measured the packing densities of cementations materials containing ordinary Portland cement, pulverized fly ash, and condensed silica fume. The results for non-blended materials revealed that the addition of a superplasticizer would

2. Kwan and Wong proposed a three-tier system design. The mix design would be divided into three stages. At the first stage, the packing density of the cementitious materials would determine the water demand, and at the second stage the aggregate particles smaller than 1.2mm would determine the paste demand and at the third stage, the aggregate particles larger than 1.2mm would determine the mortar demand.

3. Kwan and Wong used the minislump cone test to check the fresh state properties in their experimental studies. Fennis and Walraven carried out centrifugal consolidation to check the workability. Kwan and Wong obtained a curve between voids ratio and watercement ratio for cementitious materials, where the ordinary Portland cement is blended with the pulverized fuel ash and condensed silica fume in different proportions.

From the above study, it is observed that the packing density mix design method is used to minimize voids to increase particle packing and to reduce the binder content.

3. METHOD

Ordinary

Portland

cement

conforming to IS 12269-1987 locally

available river sand belonging to zone II

of IS 383-1970was used. The locally

available crushed aggregate of size 12.5

mm and 20 mm downsize conforming to

IS 383-1970 were used in the preparation

of concrete. Potable water was used in the

Tolmatti et al. Concrete Mix Design Using Particle …| 86

present investigation for both casting and curing of the concrete. Superplasticizer complies with IS 9103:1999 Sulphonated Napthelene based polymers are used. Bulk density and specific gravity test were carried out as per IS 2386(Part III)1963 and the test results are presented in Table 1.

4. RESULTS AND DISCUSSION

4.1. Design of Concrete Mix Using Packing Density Method

1. Determination of aggregate fractions

The packing density of the aggregate mixture is defined as the solid volume in a unit total volume. The aim of obtaining packing density is to combine aggregate particles to minimize the porosity, which allows the use of the least possible amount of binder. Two size fractions of coarse aggregates were selected for the study i.e., 20 and 12.5 mm down a size. The values of bulk density of the coarse aggregates (20 and 12.5 mm in size) were first determined separately.

The coarse aggregate 20 and 12.5 mm were mixed in different proportions by mass, such as 90:10, 80:20, 70:30, and 60:40, etc., and the bulk density of each mixture is determined. The addition of a smaller size aggregate (12.5 mm downsize) increases the bulk density. However, a stage is reached when the bulk density of the coarse aggregate mixture, which instead of increasing, decreases again. The results of the Bulk density of coarse aggregate fractions (20 mm and 12.5 mm) are plotted in Fig. 1.

aggregate or overall aggregate is determined from its maximum bulk density of the mixture and specific gravity. Therefore, the total packing density of the mixture is the sum of the packing density of 20 mm, 12.5 mm, and fine aggregate i.e., equal to the ratio of bulk density of mixture to the specific gravity of individual aggregate (20 mm: 12.5 mm: fine aggregate). The value of specific gravity should be taken as average if the values are differing in the third decimal and if the values are differing in the second decimal, the individual values should be taken for calculating packing density and voids content.

3. Determination of Voids Contents and Voids ratio

The voids content in percentage volume of aggregate or mixture of three aggregate is determined from its bulk density.

From Figures 2, 3, and 4, it is observed that the bulk density, packing density are maximum and voids ratio is minimum for 70 % of coarse aggregate (20 mm) and 30 % of coarse aggregate (12.5 mm) respectively.

2. Determination of Packing Density

The packing density of individual aggregate in a volume fraction of total

Fig. 2. maximum bulk density for 20 and 12.5 mm aggregates

87 | International Journal of Informatics Information System and Computer Engineering 2(1) (2021) 83-102

density, and voids ratio are plotted against the mass fraction of coarse aggregate are presented in Figures 5, 6, and 7, respectively. From Figures 5, 6, and 7, the maximum bulk density is 2.007 gm/cc, the maximum packing density is 0.722 gm/cc, and the minimum voids content is 0.2866.

Fig. 3. maximum packing density for 20 and 12.5 mm aggregate

Fig. 5. Maximum bulk density for 20 mm and 12.5 mm and fine aggregates

Fig. 4. minimum voids ratio for 20 and 12.5 mm aggregates

An increase in fine aggregate

particles leads to a decrease in void

content thus increases the bulk density.

The replacement of fine aggregates in the

total coarse aggregates (20 and 12.5 mm

downsize in the proportion of 70:30) in

the ratio of 90:10, 80:20, 70:30, 60:40, and

55:45. By increasing the finer content the

bulk density increases up to a maximum

extent after which it again reduces. Thus,

the proportion obtained for maximum

bulk density is fixed as total coarse

aggregates: fine aggregates i.e., 60:40.

Total coarse aggregate proportion i.e., 20

mm:12.5 mm is fixed as 70:30 as

mentioned

earlier.

Therefore,

proportions of these aggregates i.e.,

coarse aggregates 20 mm: coarse

aggregates 12.5 mm: fine aggregates are

42:18:40. The bulk density, packing

Fig. 6. Maximum packing density for 20 mm and 12.5 mm and fine aggregate

Fig. 7. Minimum voids for 20 mm, 12.5 mm and fine aggregate

Tolmatti et al. Concrete Mix Design Using Particle …| 88

Using the above concept, design of concrete mix is carried out for M20, M25, M30, M35 and M40 concrete mixes. A detailed sample calculation for M20 grade of concrete is presented below. The ingredients of concrete for M20 grade were obtained for 5%, 10% and 15% in excess of paste content and water-cement ratio 0.56 and 0.58 the values are presented in Table 2.

4.2. Mix Design for M20 Grade Concrete (Packing Density Method)

The calculations are presented in the following paragraph for bulk density, voids ratio and packing density.

1. Bulk density of combined coarse aggregate 20 and 12.5 mm in the proportion 70:30.

W2- W1 Bulk density =

Volume of mould

Where,

W1= empty weight of mould

W2= weight of mould + aggregate filled

Bulk density (Maximum) 35066-9800

= 15000

= 1.6840 gm / cm3

2. Bulk density of three aggregates i.e., CA 20mm : CA 12.5mm : FA is 42 : 18 : 40. (coarse aggregate 20 mm : 12.5 mm i.e., 70 : 30 as fixed earlier).

Bulk density (Maximum) 39916-9800

= 15000

= 2.0077 gm / cm3

3. Voids content:

Voids content in percent volume 2.8143-2.0077

= 2.8143 x 100 = 28.660%

4. Packing density (P.D.):

Packing density (maximum) Bulk density x weight fraction

= Specific gravity

Packing density of 20mm aggregates 2.00778x0.420

= 2.9122 = 0.2896 gm/cm3

Packing density of 12.5 mm aggregates 2.0078x0.180

= 2.9376 = 0.1230 gm/cm3

Packing density of fine aggregates 2.00778x0.400

= 2.5931 = 0.3097 gm/cm3

Total Packing Density = Packing Density of CA (20 mm) + Packing Density of CA (12.5 mm) + Packing Density of Fine Aggregate.

PD = 0.7223 gm / cm³

This packing density value is fixed for further calculations. 4.3. Determination of Paste content for

M20 Grade Concrete

89 | International Journal of Informatics Information System and Computer Engineering 2(1) (2021) 83-102

Minimum paste content is the sum of the void content in combined aggregate and excess paste over and above it to coat the aggregate particle. The meaning of minimum paste content can be explained as, a concrete mix containing minimum paste content should be cohesive, free from segregation and bleeding. Flow table tests were carried out to decide the minimum paste contents required to form the workable mix for different W/C ratios and different paste content in excess of void content.

Voids content = 1 – 0.7223 = 0.2777

Assuming paste content as 10% more than void content, detailed calculations to obtain all. Ingredients of concrete such as coarse aggregate 20 mm, 12.5 mm, fine aggregate, cement, and water content are given below.

Paste content 10% more than void content

Paste content = 0.2777 + 0.1x 0.2777

= 0.3054

Volume of aggregates = 1 – 0.3054

= 0.6945 cc

Total solid volume of aggregates

Weight fraction of 20 mm = Specific gravity +

Weight fraction of 12.5 mm Specific gravity +

Weight fraction of fine aggregate Specific gravity

Total solid volume of aggregates

0.420 0.180 0.400 = 2.9122 + 2.9376 + 2.5931

= 0.3598 cc

Weight of 20 mm aggregates

0.6945 = 0.3598 x 0.420 x 1000=810.7354 kg/cum

Weight of 12.5 mm aggregates

0.6945 = 0.3598 x 0.180 x 1000=347.4580 kg/cum

Weight of fine aggregates

0.6945 = 0.3598 x 0.400 x 1000=722.1290 kg/cum

For M20 grade concrete keeping in mind the target mean strength suitable water-cement ratio is fixed as per trial mixes.

W/C ratio = 0.56; W = 0.56C.

C 0.56C Total Paste=C+W= 3.15 + 1 =0.8775 C

0.3054 Cement content= 0.8775 x 1000

=348.1140 kg/cum Water content = 0.56 x 348.1140

= 194.9438 Kg/cum Following the above procedure, all the ingredients of concrete were obtained for 5%, 10%, and 15% in excess of paste content and water-cement ratio 0.56 and 0.58, the values are presented in Table 2.

To decide the paste content and water cement ratio among three paste content and two water cement ratios, using the above ingredients Flow Table tests were carried out. Flow Table test is carried out as per IS 1199-1959 (Indian Standard). Results of Flow table tests for M20 grade concrete indicated that water cement ratio 0.58 and all the three-paste content (i.e., 5%, 10% and 15 %) and water cement

Tolmatti et al. Concrete Mix Design Using Particle …| 90

ratio 0.56 with 5% paste content were rejected because of segregation and bleeding. Water cement ratio 0.56 with paste content of 10% and 15% in excess of void content resulted in good flow percent of 133 and 134 respectively without segregation and bleeding. For water cement ratio 0.56 in order to decide the paste content i.e., 10% and 15% in excess of void content, trial cube casting was carried out for 7 days cube compressive strength.

The average compressive strength (3 cubes) obtained at the end of 7 days curing was 22.88 N/mm and 23.666 N/mm for 10% and 15% paste content respectively. Keeping economy in mind paste content of 10% for water-cement ratio 0.56 was finalized for further casting. Mix design is carried for M25, M30, M35, and M40 grade concrete as mentioned in mix design steps for M20 grade concrete. The value of packing density remains the same irrespective of the grade of concrete because coarse aggregate 20 mm, 12.5 mm and fine aggregate used is the same for all grades of concrete. Depending on the grade of concrete paste content will vary, increases with an increase in grade of concrete. The Water-cement ratio for different grades of concrete (M25, M30, M35, and M40) is fixed as per trial mixes. Paste contents for different grades of concrete were determined using flow table tests as mentioned earlier for an individual grade of concrete finalized mix proportions are presented in Table 3.

4.4. Design of Concrete Mix Using IS Code Method

Mix design is also carried out using IS code 10262-2009 (Indian Standard). The objective of IS code method of mix design is to compare the ingredients of concrete (mix proportions) with the packing

density method and also to compare the compressive strength at 28 days in these two cases and relevant observations were discussed. Here also the final mix proportions were obtained for M20, M25, M30, M35, and M40 grade of concrete using IS method with the different trial mixes. The trial mix design for different grades of concrete was carried for different water-cement ratios and workability is checked using Flow Table tests. Accepted trial mixes were further used to cast the trial cube specimens and were tested for compressive strength at the 7 days curing age. Observing the results of trial casting the appropriate mix is finalized. This finalized mix proportion is used for further casting. Finalized mix proportions for different grades of concrete designed by IS code method are presented in Table 4.

4.5. Comparing the Mix Proportion of Concrete by IS Code Method and Particle Packing Method

1. Mix Proportions and Compressive Strength

Finalized mix proportions for M20, M25, M30, M35, and M40 grade concrete using packing density and IS code method are presented in the following tables. Using these finalized mix proportions for different grades of concrete final casting was carried out as mentioned in the following section.

In the packing density method, finalized mix proportions were used for final casting. Six cube specimens were cast (3 cube specimens for 7 days curing and 3 cube specimens for 28 days curing). Similarly, in IS method for each grade of concrete six cube specimens were cast (3 cube specimens for 7 days curing and 3 cube specimens for 28 days curing). The casting, curing, and compressive strength testing procedure was followed

91 | International Journal of Informatics Information System and Computer Engineering 2(1) (2021) 83-102

according to IS 516-1959 (see Figs. 8 and 9).

The average test result of 3 cube specimens is considered for the final test result. The results of the final casting are presented (Tables 5 and 6).

2. Workability

The variation in workability of concrete mixes designed by different methods with different water-cement ratios is presented in table 7 (KORE, S. D., & Vyas, A. K. 2017).

It can be seen from table 7, all the concrete mixes achieved their target slump of 75-100 mm. While achieving the target slump the dose of the superplasticizer is increased. In the case of the packing density method at all watercement ratios, the dose of superplasticizer required is more than that of the BIS code method. This increase is caused by the increased sand content in concrete mixes designed by the packing density method as seen in Table. On average sand, content increased by 14% in the packing density method as compared to that of the BIS code method. The increased sand content absorbs more water from the mix resulted in a stiff mix. Hence, a higher dose of super-plasticizers is required to achieve the desired workability.

3. Saving in cement content and cost comparison

Table 8 saving in cement content (KORE, S. D., & Vyas, A. K. 2017).

Table 9 shows the saving in cement content in concrete mixes designed by the packing method. From this table, it was observed that the concrete mixes designed by the packing density method are economical because of saving in cement content. The maximum saving of

18% was achieved at a 0.45 water-cement ratio. The concrete mixes designed by the packing density method showed an average 12% reduction in cement content as compared to that of the BIS code method. It depicts that the concrete mixes designed by the packing density method are economical (KORE, S. D., & Vyas, A. K. 2017).

The table shows the cost analysis of the concrete mixes. From this analysis, it was observed that the concrete mixes designed by the packing density method show a saving in the material cost of concrete. The average cost of material to produce concrete can be reduced by 11% by adopting the packing density method for the design of concrete mixes. Hence it indicates that the concrete mixes designed by the packing density method are cost-effective and economical.

4. CO2 production

The cement manufacturing industry is a major contributor to CO2 emissions in the world. The contribution of the cement industry in greenhouse gas emission is around 3.95 billion tons annually and that is 7% of the total greenhouse gas emissions on the earth’s surface. The global annual production of concrete in the year 2014 was 4.2 billion tons and it is expected that this figure may increase by 2.9 % by 2018. In India, around 275 MT of cement was produced during the year 2014 which accounts for the generation of an equal amount of CO2. To produce 1 Ton of cement around 0.94 Ton of CO2 is released. The CO2 emission factor for road transport, i.e., trucks or lorries is considered as 512.2 g/km. Table 10 reduction in carbon di oxide emission.

Tolmatti et al. Concrete Mix Design Using Particle …| 92

Table 1. The technology used in the device of virtual voting system

Sl. No

1. 2.

3.

Materials

Fine aggregates Coarse aggregate 12.5 mm Coarse aggregate 20 mm

Bulk density Kg/m3

(Compacted condition) 1600.133 1387.777

1525.555

Bulk density Kg/m3 (Loose

condition) 1718.063 1542.222

1660.000

Specific gravity

2.593 2.937

2.912

Table 2. Trial mix proportions for M20 grade concrete

Grade of W/C concrete ratio

Excess paste content (%)

0.58 5

Water content (Kg/m3)

Cement content (Kg/m3)

188.4416 0.58

324.8994 1

Wt. Of Fine aggregate (Kg/m3)

787.6736

2.4243

Wt. Of 12 mm Coarse aggregate (Kg/m3)

354.4531

1.0817

0.58 10

197.4151 0.58

340.3708 1

772.2352 2.2688

347.5058 1.0209

0.58 15 M20

0.56 5

206.3885 0.58 186.0907 0.56

355.8422 1 332.3048 1

756.7967 2.1268 787.6736 2.3703

340.5585 0.9570 354.4531 1.0667

0.56 10

194.9522 0.56

348.1289 1

772.2352 2.2182

347.5058 0.9982

0.56 15

203.8136 0.56

363.9529 1

756.7967 2.0794

340.5585 0.9357

Wt. Of 20 mm Coarse aggregate (Kg/m3) 827.0573

2.5455

810.8469

2.3822

794.6366

2.2331

827.0573

2.4889

810.8469

2.3292

794.6366

2.1834

## Categories

## You my also like

### Chapter 3: Physical Properties of Structural Lightweight Aggregate

4.9 MB40.8K15.9K### Standard operating procedure for saturated soil paste extract

4.9 MB7.4K3.3K### Experimental Study of M20 Grade Concrete using Packing

392.7 KB53.4K20.3K### Chute Design Considerations For Feeding And Transfer

322.2 KB4.1K1.4K### Precious Shipping Public Company Limited

2.9 MB49.2K24.6K### Bulk Deformation Processes

1.4 MB19.9K6.4K### Ethnobotanical Studies of Adilabad District, Andhra Pradesh, India

1.1 MB51.4K5.1K### ISSN Ethnobotanical Studies of Adilabad District, Andhra N

1.1 MB22.7K4.1K### Anchovy paste production from lactic acid fermentation of

811.7 KB6.2K1.3K