Group 22 Assignment 8 Final Draft

8/18/2019 Group 22 Assignment 8 Final Draft

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ASSIGNMENT 8

MIX DE IGN

GROUP 22

Roelof JacobsBenedicto Munthali

John RoxburghTholly Vezi

Kevin Volmink (rou! "eader#Word Count

Main text $%%%

Tables (13 x 150) &'$%

Figures (5 x 150) $%

Total %%


2/34

GROUP !""#G$M%$T & M#' %"#G$

Grou !ssign*ent &+ Mix esign

&) * concrete is to be !roduced from the follo+ing materials,

• -.M/ 0ortland cement $1)$2 (B3 .2 &'4

• * gravel (uncrushed# coarse aggregate and an uncrushed fine aggregate +ith the

!ro!erties given in Tables & and 1 res!ectively (B3 .2 &151%#• Ta! +ater (B3 .2 &%%6#

7esign a concrete +ith strength -lass -8%98 and consistence -lass 38 (B3 .2 1%54using

(a# the 7o. mix design method(b# the *-/ method(c# the Basic Mix method)

There are no limiting values for the com!osition and no other s!ecified concretere:uirements)

1) -om!are and contrast the three mix design methods used in ;&< and in !articular

comment on their ease of use and any differences in the resulting concrete com!ositions)3tate +hich one of the mix designs you consider to be the best< giving reasons for your selection)

8) =o+ +ould you ad>ust the com!osition that you obtained in :uestion &(a# to !roduce(a# a !um!able concrete(b# a flo+ing concrete(c# an under+ater concrete(d# a self4com!acting concrete to .?2*R- classes 3?8< V3&9V?&< 0*1 and 3R1(e# an air4entrained concrete)

?or each of these you should design a mix for the same strength class as in ;&< and youcan incor!orate any other constituent materials locally available to at least one of the grou!

members in addition to those given in ;& above)

@) =o+ +ould you modify the mix com!osition that you obtained in :uestion &(a# to achievemaximum sustainability benefits if you +ere also able to use one or more of,

(a# fly ash conforming to B3 .2 @$%4& (-ategory 2#(b# ground granulated blastfurnace slag conforming to B3 .2 &$&54&(c# limestone !o+der to B3 ''

2otes,

• Aou should clearly set out your reasoning< calculations< assum!tions etc) for each

!art of ;&< ;8 and ;@)

• The conclusion to each !art should be the com!osition that you +ould use for an

initial trial mix< either in the laboratory or in a batching !lant) These are of course bestestimates and in !ractice may need ad>ustment de!ending on the results of the trialmix)

• /n ;8 you should also include details of the materials you have chosen to use

(including the manufacturers data sheets#)

• The *-/ and Basic Mix 7esign methods are !rovided in the Mix 7esign section of the

library)

• O,erall *axi*u* lengt- .000 /ords (excluding re!ort title !age< contents<

reference list and a!!endices< but including +ords in tables# +ith each diagram<figure etc) +ithin the main text to count as &$% +ords) .nsure that the +ord length isdeclared in the re!ort)


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GROUP !""#G$M%$T & M#' %"#G$

%'%CUT#% "UMM!R

* class -8%98 strength concrete mix +ith a class 38 consistence using s!ecific materials

+as sort) Three concrete mix design methods< 7o.< *-/ and Basic< +ere used to determine

the mix !ro!ortions based on re:uired concrete and material !ro!erties) These methods

+ere com!ared +ith reference to their ease of use and the differences in the concrete mix

design obtained from each) The 7o. and basic mix design methods +ere found to be more

accurate in the determination of the initial mix design) The com!osition of the initial mix

design +as then ad>usted< +hilst maintaining the strength re:uirements< to !roduce various

s!ecial concretes) This +as achieved by blending the s!ecified materials< using additions

and admixtures) ?inally the initial mix +as modified to achieve the maximum sustainability

benefits by inco!orating fly ash< B3 and limestone in various !ro!ortions)

i


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GROUP !""#G$M%$T & M#' %"#G$

T!2% OF CO$T%$T"

Page $o

1.CO$CR%T% M#' %"#G$ 41.1 Mix 7esign Re:uirements 5

1.1.1 /ntroduction5

1.1.2 0erformance re:uirements5

1.1.3 Materials 5

1.1.4 Target mean strength (to be used for all mix designs#

1.2 7o. mix design

1.2.1 3tage &, 3election of target +ater9cement ratio

1.2.2 3tage 1, 3election of free4+ater content 6

1.2.3 3tage 8, 7etermination of cement content '

1.2.4 3tage @, 7etermination of total aggregate content '1.2.5 3tate $, 3election of fine and coarse aggregate contents&%

1.3 *-/ Mix design &&

1.3.1 3te!&, -hoice of slum! &&

1.3.2 3te! 1, -hoice of maximum aggregate size &&

1.3.3 3te! 8, .stimation of mixing +ater&&

1.3.4 3te! @, 3election of +ater C cement ratio &&

1.3.5 3te! $, -alculation of cement content &&

1.3.6 3te! 5, .stimating coarse aggregate content &1

1.3.7 3te! , .stimation of fine aggregate content &1

1.4 Basic Mix Method &11.5 -onclusion &8

2. COMP!R#"O$ OF M#' %"#G$ M%TO" 16

2.1 /ntroduction &@

2.2 Result com!arison &@

2.3 .ase of use of the different methods &$

2.4 7etermination of free +ater content) &5

2.5 7etermination of +ater to cement ratio &5

2.6 7etermination of aggregate content&5

2.7 -onclusion &

3. M#' !7U"TM%$T FOR "P%C#! CO$CR%T%" 1&

3.1 3elf -om!acting -oncrete &6

3.1.1 Mix design considerations &6

3.1.2 Mix design calculations &'

3.2 *ir entrainment mix design 1&

4. M#' MO#F#C!T#O$ FOR "U"T!#$!2##T

4.1 /ntroduction 11

4.2 ?ly *sh -ategory 2 (.2 @$%4 11

4.3 B3 (.2 &$&544.4 "imestone !o+der to B3 '' 18

5. R%F%R%$C%" 5

ii


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GROUP !""#G$M%$T & M#' %"#G$

!PP%$#' ! 1

iii


6/34

GROUP !""#G$M%$T & M#' %"#G$

#"T OF F#GUR%"

?igure &4& *!!roximate com!ressive strength (29mm1# of concrete mixes made +ith a free4+are9cement ration of %)$)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))

?igure &41 Relationshi! bet+een com!ressive strength and free4+ater9cement ratio)))))))))))))6

?igure &48 *!!roximate free4+ater contents (kg9m8# re:uired to give various levels of

+orkability))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))'

?igure &4@ .stimated +et density of fully com!acted concrete)))))))))))))))))))))))))))))))))))))))))))))&%

?igure &4$ (continued#))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))&&

iv


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GROUP !""#G$M%$T & M#' %"#G$

#"T OF T!2%"

Table &4& -oarse (gravel# aggregate))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))5

Table &41 Dncrushed fine aggregate)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))5

Table &48 Eone of sand for given grading)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))&1

Table &4@ 3ummary of mix design results)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))&8

Table 14& Mix design results from different team members)))))))))))))))))))))))))))))))))))))))))))))))))))&$

Table 141 *-/ mix design re+orked +ith +9c of %)$1)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))&$

Table 84& 3ummary of s!ecifications according to .?2*R- 1%%$)))))))))))))))))))))))))))))))))))))))&6

Table 841 3-- mix ad>ustment com!utation)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))&'

Table 848 -om!arison of *-/ :uestion & mix and !ro!osed air entrained mix))))))))))))))))))))))1&

Table @4& Mix to be modified for sustainability))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))11

Table @41 Mix modified by adding fly ash))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))11

Table @48 Mix modified by adding B3))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))18

Table @4@ Mix modified by adding limestone)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))18

v


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GROUP !""#G$M%$T & M#' %"#G$

1. CO$CR%T% M#' %"#G$

1.1 Mix esign Re8uire*ents

1.1.1 #ntrodu9tion

Dsing three different mix design methodologies< a mix design is created using each

methodology +ith the given in!ut materials) The follo+ing methodologies are used)

The 7o. mix design method) This is a British method of mix design and +as first

!ublished in the Road Research "aboratoryFs GRoad 2ote 2o) @F (Road Research

"aboratory< &'$%#) /t +as subse:uently revised in &'$ and again revised and

u!dated in &'66 in the !ublication H7esign of normal concrete mixesI (Teychenne<

et al)< &'66#)

The *-/ (*merican -oncrete /nstitute# method is a method develo!ed by *-/

committee 1&& +hich is described in the *-/ !ublication H3tandard 0ractice for

selecting !ro!ortions for 2ormal< =eavy+eight< and Mass -oncrete (*-/ 1&&)&4'

(*-/ -ommittee 1&&< 1%%'#

The Basic Mix Method is a method !ro!osed by +ens in the Basic mix series

!ublished by the -ement and -oncrete association (+ens< &'8#)

1.1.2 Per:or*an9e re8uire*ents

3trength class -8%98) -onsistence class 38 as !er B3 .2 1%54& (B3 .2 1%54

&,1%%%< 1%%@#) B3 .2 1%54& describes a consistence class of 38 as having a slum!

of bet+een &%% mm and &$% mm

1.1.3 Materials

-oarse aggregate, ravel (uncrushed# +ith maximum nominal size of 1% mm

irregular in sha!e) *s !er Table &4& in assignment)

Grading Sieve size % passing bywt

20mm10mm

4mm2mm

9635

41Parti!e density"SS#$

2.650 g&m3

#ry r'dded b(!)density

1.46 g&m3

Parti!e s*ape irreg(!ar

?ine aggregate, Dncrushed fine aggregate +ith !ro!erties given in Table &41 of

assignment) ?rom Table &41 in assignment the !ercentage fines !assing the 5%%

micron sieve being $1) The fineness modulus +as calculated to be 1))

Grading Sieve size % passing bywt

4mm2mm

9+79

5

Table 1;1 Coarse (gra,el) aggregate Table 1; Un9rus-ed :ine aggregate


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GROUP !""#G$M%$T & M#' %"#G$

1mm0.5mm

0.25mm0.125mm

6752225

"grading z'ne 2 ,'r -asi i

et*'d$Parti!e density"SS#$

2.65 g&m3

-ement, -.M / 0ortland cement $1)$2 in accordance +ith B3 .2 &'4&

Later meeting the re:uirements of B3 .2 &%%6)

1.1.4 Target *ean strengt- (to be used :or all *ix designs)

*ssuming $ defectives allo+ed and a standard deviation of 5M0a as obtained

from G7esign of 2ormal concrete mixesF (Teychenne< et al)< &'66#)

Target mean strength f m 8 N (&)5@ x 5# 6.MPa

1.2 o% *ix design

1.2.1 "tage 1+ "ele9tion o: target /aterust the strength do+n to @M0a

and a target +ater cement ratio of 0=5


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6


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GROUP !""#G$M%$T & M#' %"#G$

1.2.2 "tage + "ele9tion o: :ree;/ater 9ontent

3election of free +ater content from ?igure &48

?ree +ater content of 1>5 litres +as obtained for uncrushed aggregate of maximum

size 1%mm

'

Figure 1;1 !roxi*ate 9o*ressi,e strengt- ($


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GROUP !""#G$M%$T & M#' %"#G$

1.2.3 "tage 3+ eter*ination o: 9e*ent 9ontent

-ement content free4+ater content 9 (free4+ater9cement ratio#

&'$ 9 %)$1 3.5?g o: 9e*ent=

1.2.4 "tage 6+ eter*ination o: total aggregate 9ontent

?rom ?igure &4@ the +et density is calculated at 18$$ kg9m8 assuming an aggregate

relative density of 1)5$

Total aggregate content Let density of concrete C cement content C free4+ater

content

18$$ C 8$ C &'$ &6$kg9m8

&%

Figure 1;3 !roxi*ate :ree;/ater 9ontents (?g


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GROUP !""#G$M%$T & M#' %"#G$

1.2.5 "tate 5+ "ele9tion o: :ine and 9oarse aggregate 9ontents

?rom sand grading Table &41 the !ercentage !assing the 5%% micron sieve is $1)

Dsing ?igure &4$ the !ro!ortion of fine aggregate is found to be @1)

Therefore fine aggregate content %)@1 x &6$ .50 ?g

*nd coarse aggregate content &6$ C $% 1035?g

&&

Figure 1;6 %sti*ated /et densit@ o: :ull@ 9o*a9ted 9on9rete

1.1.1


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GROUP !""#G$M%$T & M#' %"#G$

1.3 !C# Mix design

*ll tables referred to in this section are tables +ithin the *-/ !ublication H3tandard0ractice for selecting !ro!ortions for 2ormal< =eavy+eight< and Mass -oncrete

(*-/ -ommittee 1&&< 1%%'#)

1.3.1 "te1+ C-oi9e o: slu*

iven to be &%% C &$%mm

1.3.2 "te + C-oi9e o: *axi*u* aggregate siAe

?rom assignment to be a maximum size of 1%mm)

1.3.3 "te 3+ %sti*ation o: *ixing /ater

?rom Table 5)8)8< 8$% !ounds of +ater !er cubic yard +ere obtained for O inch

aggregate and a slum! of bet+een @ and 5 inches)

-onverted to metric units it comes to 1%kg9m8

1.3.4 "te 6+ "ele9tion o: /ater B 9e*ent ratio

Based on a 16 day cylinder strength (a!!lying same margin as to cube above# of

@%M0a ($6%& 03/# inter!olating Table 5)8)@(a# gives a +ater to cement ratio of 0=6=

1.3.5 "te 5+ Cal9ulation o: 9e*ent 9ontent

?rom ste!s 8 and @

-ement content +ater content 9 (+ater cement ratio#

1% 9 %)@1 @'1kg9m8)

&1

Figure 1;5 (9ontinued)

1.2


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GROUP !""#G$M%$T & M#' %"#G$

1.3.6 "te 4+ %sti*ating 9oarse aggregate 9ontent

0ercentage volume of coarse aggregate !er unit volume of concrete obtained from

table 5)8)5 using a fineness modulus of 1) (as calculated above# is 58 hence

volume of coarse aggregate is,

%)58 x & 58% litres

=ence mass of coarse aggregate is %)58 x &@5% '1%kg (the consolidated bulk

density given in assignment as &@5%kg9m8#)

1.3.7 "te .+ %sti*ation o: :ine aggregate 9ontent

?irstly the !lastic density of the fresh concrete is estimated from Table 5)8))& and

this give (after conversion# an estimated density of 18$% kg9m8

The mass of fine aggregate is calculated as follo+s

Mass fine aggregate mass concrete C mass +ater C mass cement C mass coarse

aggregate

18$% C 1% C @'1 C '1% .31 ?g


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GROUP !""#G$M%$T & M#' %"#G$

1.5 Con9lusion

* summary of the mix design results using the different methods is given in Table &4

@ belo+)

o% !C# 2!"#C

Later &'$ 1% &'$

-ement 8$ @'1 8$%

?ine agg $% 8& 1%

-oarse agg &%8$ '1% &%@%

7ensity 18$$ 18$% 18%$

&@

Table 1;6 "u**ar@ o: *ix design results


17/34


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GROUP !""#G$M%$T & M#' %"#G$

o% !C# 2asi9

TV

Later kg9m8 1%1 &'$

-ement Kg9m8 @1% 8$%L9- %)@6 %)$5

?ine aggregate kg9m8 @@% 1%

-oarse aggregatekg9m8

6@ &%@%

0lastic density kg9m8 &6@$ 18%$

BM

Later kg9m8 &'$ 1%% &'$

-ement Kg9m8 @%5 @@' @68

L9- %)@6 %)@$ %)@%

?ine aggregate kg9m8 '$6 '5 5&%-oarse aggregatekg9m8

6&5 '&% &%@%

0lastic density kg9m8 18$ 18$$ 181'

KV

Later kg9m8 &'$ 1%$ &'$

-ement Kg9m8 @1@ @$5 8$%

L9- %)@5 %)@$ %)$5

?ine aggregate kg9m8 $'8 @ 1%


&&@6 '1% &%@%

0lastic density kg9m8 185% 18$$ 18%$

JR

Later kg9m8 &'$ 1% &'$

-ement Kg9m8 8$ @'1 8$%

L9- %)$1 %)@1 %)$5

?ine aggregate kg9m8 $% 8& 1%


&%8$ '1% &%@%

0lastic density kg9m8 18$$ 18$% 18%$

o% !C#

Later kg9m8 &'$ 1%

-ement Kg9m8 8$ 8'6

L9- %)$1 %)$1

?ine aggregate kg9m8 $% 61$


&%8$ '1%

0lastic density kg9m8 18$$ 18$%

2.3 %ase o: use o: t-e di::erent *et-ods

*ll mix designs +ere easy to use) *ll methods relied on looking u! figures on tables

or gra!hs and the design !rocess +as done in stages) The Basic mix design

involved looking u! an initial mix on a set of tables and then this mix +as ad>usted

&5

Table ;5 Mix design results :ro* di::erent tea* *e*bersTable ;4 !C# *ix design re/or?ed /it- /


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GROUP !""#G$M%$T & M#' %"#G$

to meet the strength re:uirements) The Basic mix design method +as not able to

cater for the @M0a re:uired strength for the given +ater content in the initial given

mix) 2o clear !rocedure +as given to remedy this as the design did not cater for

the changing of the +ater content to meet the re:uirements but rather relied on

changing the cement contents) (/t should be noted that GBasic Mix MethodF booklet

states on the front cover that this method is for H3election of !ro!ortions for medium

strength concretesI and as this +as !ublished in &'8 a @M0a concrete may have

been a!!roaching +hat +ould have been classified as high strength#)

2.4 eter*ination o: :ree /ater 9ontent=

The 7o. method looked this u! on a table using the maximum size of aggregate

and the ty!e of aggregate (crushed or uncrushed# along +ith the re:uired slum! as

in!ut !arameters)

The *-/ method also used the maximum aggregate size and slum! as !arameters

to look u! the free +ater content on a table but makes no distinction for theaggregate sha!e like the 7o. method)

The Basic mix design determines the free +ater content by actual mixes done

taking into account the sand grading and stone sha!e (rounded< irregular or

angular#)

*s the 7o. and Basic mix designs returned lo+er free +ater contents and take the

stone sha!e into account it suggests that they +ill give a more accurate measure of

the free +ater content)

2.5 eter*ination o: /ater to 9e*ent ratio

?or the 7o. method the +9c ration is looked u! on a table +hich caters for different

ty!es of cement and the stone sha!e)

The *-/ method uses a table to determine the ratio but only +ith a given strength

as the in!ut !arameter)

The Basic mix design method determines the +ater cement ratio by ad>usting the

cement content in the initial mix design found on a table taking into account the

sand grading and stone sha!e)

/t +ould stand to reason that the 7o. and Basic mix design method +ould return a

better a!!roximation of the re:uired +9c ratio due to the use of more in!ut

!arameters in its determination) The Basic mix design does not cater for a shift in

+ater content to get the re:uired +9c ratio and hence could not cater for the @M0a

re:uirement)

2.6 eter*ination o: aggregate 9ontent

The 7o. mix design determines the overall aggregate content by !redicting the

density of the concrete and then subtracting the free +ater and cement content from

this) The aggregate content is then !ro!ortioned into coarse and fine contents using

tables that take the slum!< maximum aggregate size< +ater cement ratio and also

the grading of the fine aggregate (namely the !ercentage of material smaller than

5%% microns# into account)

&


20/34

GROUP !""#G$M%$T & M#' %"#G$

The *-/ method used a table that takes into account the maximum aggregate size

and the fineness modulus of the sand to look u! the coarse aggregate content) The

fine aggregate content is then calculated by difference after estimating the concrete

density off a table)

The Basic mix design method determines the coarse and fine aggregate contentsby doing initial trial mixes that are listed in a table) The coarse aggregate content

then remains the same +hile the fine aggregate content is ad>usted +hen the

cement content is changed to get the correct +9c ratio)

The 7o. and Basic mix design methods make use of both coarse aggregate sha!e

and fine aggregate grading along +ith the maximum aggregate size to determine

the contents of these in the mix) The *-/ method only uses the maximum

aggregate size and the fineness modulus of the sand to determine the aggregate

!ro!ortions and :uantities) The fineness modulus does not say anything about the

grading of the sand +hich is a crucial !arameter for the +orkability of the mix)

2.7 Con9lusion

The 7o. and Basic mix design methods cater for stone sha!e and sand

grading in their determination of +ater content and aggregate content +hile

the *-/ method does not) ?or a more accurate !rediction of an initial mix

design it +ould a!!ear that 7o. and Basic mix design +ould be a better

choice)

&6


21/34


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GROUP !""#G$M%$T & M#' %"#G$

hydration and hence minimize thermal cracking) /t +ill also im!rove +orkability

reduce segregation and bleeding in the concrete)

/n order to achieve the second and third !oints< our mix of :uestion & shall bead>usted as follo+s

-oarse aggregate to be blended< $% &8)1 mm stone and $% &% mm stone)

This is to be verified +ith initial tests)

-oarse aggregate to be set at $% dry robbed +eight for concrete

?ine aggregate to be set at @% of mortar volume

3.1.2 Mix design 9al9ulations

There are no standard methods for 3-- mix design and many academic

institutions< admixture< ready4mix !recast and contracting com!anies have

develo!ed their o+n mix methods (.?2*R-< 1%%$#) The method used to ad>ust the

:uestion & mix design is ado!ted from a !a!er from the /nternational Journal of

*dvances in .ngineering P Technology entitled A SIMPLE TOOL FOR SELF

COMPACTING CONCRETE MIX DESIGN ( J) uru Ja+ahar< -) 3ashidhar< /)V)

Ramana Reddy and J) *nnie 0eter< 1%&1#) ?or flo+ability< the maximum aggregate

size has been limited to &8)1mm and the mix is a $%9$% blend of &%mm and &8)1mm

aggregate< the +ater content has been fixed to match +ith the :uestion & mix< free

+9c has been ad>usted to %)@ and binder content calculated based on this< the

com!utation is given belo+ in Table 84&

-oarse aggregate blending $% $%

3!ecific gravity of &8)1mm P

&%mm

1)&

7ry robbed &@5% kg9m8

-oarse aggregate in dry

robbed

$%

-oarse aggregate +eight 8% kg9m8

-oarse aggregate volume 15')8 litre9m8

15)'@

Mortar volume -oncrete volume 4 coarse aggregate

volume&%%%415')8

8%)58 litre9m8

of sand in Mortar volume @8)% ?ultons !g) 81@

3and volume 8%)58U@88&@)@$ litre9m8

s!ecific gravity cement 8)&$

1%

Table 3;& "CC *ix adEust*ent 9o*utation


23/34

GROUP !""#G$M%$T & M#' %"#G$

3!ecific gravity fly ash 1)&1 *ssumed

*ir content 1 assumed

Later 9 binder ratio %)@ try

of fly ash by +eight 8%

volume of ".2/DM $%% by

+eight of binder

%)6 litre !er &%% kg of binder

volume of ".2/DM 3TR.*M

1 by +eight of binder

%)&$ litre !er &%% kg of binder

Binder $&1)$ kg9m8

?ly ash &$8)$ kg9m8

-ement 8$6)$ kg9m8

Later 1%$ litre9m8

Volume of cement &&8)' litre9m8

Volume of ?ly ash 1)$ litre9m8

".2/DM $%% @)%% litre9m8

".2/DM 3TR.*M 1 %) litre9m8

Total 0aste Volume @&5)&6 litre9m8

-alculations of constituent material for

concrete3!ecific gravity of sand 1)&

of absor!tion of 1%mm %)8 *ssumed

of absor!tion of &%mm %)8 *ssumed

of absor!tion of sand %)& *ssumed

of moisture in 1%mm %

of moisture in &%mm %

of moisture in sand %

of dry material in ".2/DM

$%%

$%

of dry material in ".2/DM

3TR.*M 1

$%

-ement 8$6)$ kg9m8

?ly ash &$8)$ kg9m8

/nitial +ater content 1%$ litre9m8

-oarse aggregate 8% kg9m8

1%mm coarse aggregate 85$ kg9m8

&%mm coarse aggregate 85$ kg9m8

3and 6$1)&$ kg9m8

3.2 !ir entrain*ent *ix design

*ccording to ?ultons< our mix design from :uestion one +ill be ad>usted as follo+s

(+ens< 1%%'#•

Reduce +ater content by • /ncrease cement content by @% kg to get a rich mix (8% M0a#• Dse the same amount of stone

1&


24/34

GROUP !""#G$M%$T & M#' %"#G$

• /nclude air volume in the mix design

n the last !oint< ty!ical air content is bet+een 1 to 5 but the minimum s!ecified

is 8 (Dnkno+n< 1%&1#

Dsing the above guide the !ro!osed air entrained mix for for trial is given belo+ in

Table 848

ACI mix for

Q 1

Air

entrained

mix

/ater !&m3 205 191

ement )g&m3 456 496

ine aggregate )g&m3 774 774'arse aggregate)g&m3

920 920

ir entrainment agent%

3

The !ro!osed air entrainment admixture to be used is MB4*. '% !roduced by

B*3?) *!!endix * has the !roduct data sheet) The first trail mix +ill start +ith 86)1

ml of admixture therefore the first trail mix +ill be as follo+s• Later &'& l9m8

• -ement @'5 kg9m8

• ?ine aggregate @ kg9m8

• -oarse aggregate '1% kg9m8

• MB *. '% %)%86 l9m8

11

Table 3;> Co*arison o: !C# 8uestion 1 *ix and roosed air entrained *ix


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4. M#' MO#F#C!T#O$ FOR "U"T!#$!2##T

4.1 #ntrodu9tion

The use of extenders fly ash< slag and limestone filler has been !roven in the !ast

to have benefits on the density of the concrete as +ell as the strength gain at later

ages) Lith one of the !rimary reasons for use being the reduction in carbon

foot!rint and cost) The mix to be modified for sustainability is given in Table @4&

belo+)

Base mix R)7) Aield

Later kg9m8 1%$ &


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GROUP !""#G$M%$T & M#' %"#G$

4.3 GG2" (%$ 1514.;1)

B3

mix R)7) AieldLater kg9m8 1%% &)%% 1%%

-ement kg9m8 116 8)&@ 8

B3 kg9m8 116 1)6@ 6%

-ourse *ggregate kg9m8 '1% 1)$5 8$'

?ine *ggregate kg9m8 % 1)5$ 1'&

&%%8 Total

L9- %)@@

The use of B3 varies from 1$ to $% of +eight of the cement< (Malhotra<&''# this is in line +ith +hat the RM- us is in 3outh *frica)

B3 also has a +ater reduction of 14$ due to it being able to increase the slum!

and ease the com!action of the concrete (Malhotra< &''#) This is ho+ever all

de!endand on the ty!e of grinding that took !lace and the sha!e and size of the

B3 !artiacal)

The same as +ith fly ash there is a delayed setting but +ith a higher rate of strength

gain at early age as com!ared to fly ash (8day#) /t +ill have a lo+er strength at

16days com!ared to the base mix but $54'%days +ill be higher)

*d>ustments +ill have to be made to the L9- if the same 16days cube results are

re:uared)

4.4 i*estone o/der to 2" .>.>

"imestone is usually considered to be the !oorest !otential !erformer of cement 9

concrete extention material) (M) -om!ton< Volume 86 2o

"imestone mix R)7) Aield

Later kg9m8 1%8 &)%% 1%8

-ement kg9m8 @1&)6 8)&@ &8@

"imestone kg9m8 8@)1 1)5$ &8

-ourse *ggregate kg9m8 '1% 1)$5 8$'

?ine *ggregate kg9m8 % 1)5$ 1'&

&%%% Total

L9- %)@$

The limestone !o+der is usually used and an inert fine filler in concrete at about <

$ (M) -om!ton< Volume 86 2o) /t is usually also finer than the cement !article

and thus im!roves the density of the concrete as +ell as having a small

im!rovement on the +orkability due to !article size distribution)This might increase the strength slightly but not significantly) /n some cases +hen

using higher than )$ re!lacement a lo+er strength at 16days +ill be achieved<

but +ith similar $54'%day strength com!ared to the base mix) (.) unyisi< 1%&

1@

Table 6;1 Mix *odi:ied b@ adding GG2"Table 6;13 Mix *odi:ied b@ adding li*estone


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GROUP !""#G$M%$T & M#' %"#G$

5. R%F%R%$C%"

$%@$%< 3) .) (1%&) SANS EN 50450-1:2011. 0retoria, 3*23)

.) unyisi< M) ) (1%&) 0ro!erties of self4com!acting !ortland !ozzolana and

limestone blended cement concrete containing defferet re!lacement levels of slag)Materials and structures < &8''4&@&%)

=) Lang< -) ;) (1%%5#) /nter reaction of materials used in concrete) Concrete

International < @54$1)

M) -om!ton< J) -) (Volume 86 2o) .levated limestone mineral addition im!acts

on laboratory and firld concrete !erformance) Feature: Concrete Technoloies < 14

88)

Malhotra< V) (&''#) Su!!le"entar# Ce"entin Materials - For concrete.

*-/ -ommittee 1&&< 1%%') 3tandard 0ractise for 3electing 0ro!ortions for 2ormal<

=eavy+eight< and Mass concrete < ?armington =ills< Michigan, *merican -oncrete

/nstitute)

B3 .2 1%54&,1%%%< 1%%@) -oncrete 4 0art &,3!ecification< !erformance< !roduction

and conformity) s)l),British 3tandards /nstitute)

2e+man< *) J) P Teychenne< 7) -)< &'5@) * technical and historical revie+ of the

sand grading re:uirements in British 3tandard 661U) "ondon< 3and and ravel

*ssociation of reat Britian)

+ens< 0) ")< &'8) Basic Mix Method< 3election of !ro!ortions for medium strength

concretes< "ondon, -ement and -oncrete *ssociation)

Road Research "aboratory< &'$%) Road 2ote 2o)@ 7esign of -oncrete Mixes) 1nd

ed) =armonds+orth, 7e!artment of 3cientific and /ndustrial research)

Teychenne< 7) -)< ?ranklin< R) .) P .rntroy< =) -)< &'66) Building Research

.stablishment re!ort) 7esign of normal concrete mixes) Revised edition ed)

arston, 7e!artment of .nvironment)

B3 .2 &'54&,1%%$< 1%%$) Methods of testing cement< 0art &, 7etermination of

3trength) s)l),British 3tandards /nstitute)

.?2*R-) (1%%$#) The Euro!ean $uidelines %or Sel%-Co"!actin Concrete. DK,

.?2*R-)

J) uru Ja+ahar< -) 3ashidhar< /)V) Ramana Reddy and J) *nnie 0eter) (1%&1#) *

3/M0". T" ?R 3."? -M0*-T/2 -2-R.T. M/ 7.3/2)

International &ournal o% Ad'ances in Enineerin ( Technolo# (!!) $$%4$$6#)

/ndia, /nternational Journal of *dvances in .ngineering P Technology)

+ens< ) (1%%'#) Fulton)s Concrete Technolo#. Midrand, -ement P -oncrete

/nstitute


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GROUP !""#G$M%$T & M#' %"#G$

*00.27/ *

* 4 &


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GROUP !""#G$M%$T & M#' %"#G$

* 4 1


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GROUP !""#G$M%$T & M#' %"#G$

* 4 8


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* 4 @


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GROUP !""#G$M%$T & M#' %"#G$

* 4 $


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GROUP !""#G$M%$T & M#' %"#G$

* 4 5


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Documents

Group 22 Assignment 8 Final Draft