Initial and Final Setting Time of Cement

Initial and Final Setting Time of Cement Code: IS 4031 part 5:1988 Determination of Initial and Final setting time of cement Aim: To determine the initial and final Setting of cement Apparatus: 1. icat apparat!s ". #alance of 1$g capacit% and sensiti&it% of 1 gms 3. 'a!ging tro(el 4. )ement specimen to *e tested 5. +ota*le (ater  ,.-eas!ring ar  /. Stop (atch Theory: In act!al constr!ction dealing (ith cement paste mortar concrete certain time is re!ired for mi2ing transporting and placing. D!ring this time the cement mi2t!re sho!ld *e in a plastic condition. The time period for (hich the cement mi2t!re sho!ld remain in plastic condition is $no(n as setting time. Initial setting time:  Time elapsed *et(een the moment that the (ater is added to the cement to the time at (hich the cement starts losing its plasticit%. r 

The time lag *et(een the time at (hich (ater is added to the cement and the time at (hich the needleneedle ) fails to pierce the test *loc$ *% 5 to / mm from the *ottom (ill *e the initial setting time of cement

Final Setting time:  Time elapsed *et(een the moment that the (ater is added to the cement to the time at (hich the cement completel% loses its plasticit%.

r  The time lag *et(een the time at (hich (ater is added to the cement and the time at (hich the needle 6eedle F fails to ma$e an impression (ill *e the Final setting time of cement

Prepared by: Prof Hanamant Hunashika

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Application: 7sed to detect the deterioration of cement d!e to storage Significance: s the loss of plasticit% in cement starts soon after attaining initial setting time of cement the mi2ing transporting and placing of cement concrete sho!ld ta$e place *efore initial setting. s the final setting time approaches the cement *ecomes harder and harder  th!s ma$ing it impossi*le to *e !sed. Test condition and environment

7nless specified the test sho!ld *e cond!cted at a temperat!re of "/" ) and relati&e h!midit% of ,55 ; Procedure for sample preparation

1. ". 3. 4. 5.

Ta$e a*o!t 300 gms of cement passing thro!gh 90 < sie&e dd a*o!t 0.85 times the (ater re!ired to prod!ce a paste of normal consistenc% +orta*le or distilled (ater sho!ld *e !sed to form the paste Start the stop (atch at the instant (hen (ater is added to the cement -i2 the cement and (ater to a point (hen gloss% s!rface appears at the top Prepared by: Prof Hanamant Hunashika

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,. Fill the paste in the icats -o!ld (ith non=poro!s *ase plate and smoothen the top s!rface Determination of Initial Setting time of Cement

1. +lace the test *loc$ confined in the mo!ld and resting on a non=poro!s plate !nder the road *earing 6eedle ) for initial Setting time of cement. >o(er the needle gentl% to *ring it in contact (ith the top s!rface of the test *loc$ and !ic$l% release allo(ing it to penetrate into the test *loc$  ". In the *eginning the needle (ill completel% pierce the test *loc$  3. ?epeat the proced!re !ntil the needle (hen *ro!ght in contact (ith test *loc$ and released as mentioned a*o&e fails to pierce the *loc$ to a point *e%ond 5 to / mm meas!red from the  *ottom of the mo!ld

Final Setting time of cement

1. ?eplace the 6eedle ) (ith 6eedle F i.e (ith the ann!lar attachments ". +lace the test *loc$ confined in the mo!ld and resting on a non=poro!s plate !nder the rod *earing 6eedle F for Final Setting time of cement. >o(er the needle gentl% to  *ring it in contact (ith the top s!rface of the test *loc$ and !ic$l% release. 3. ?epeat the proced!re !ntil the point needle ma$es and impression *!t the attachment fails to do so !servation

Determination 6o  6ormal )onsistenc% of cement Time @hen @ater is dded to the cement Time at initial Setting Total Time ta$en for Initial Setting Time at Final Setting Total Time ta$en for Final Setting

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"eporting the "esults:

?eport the res!lts of initial and final setting time in -in!tes Conclusion

Initial Setting time of cement is

min

Final Setting time of cement is

min

Discussion: The gi&en sample satisfiedA does not satisf% the re!irement of initial setting Prepared by: Prof Hanamant Hunashika

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The gi&en sample satisfiedA does not satisf% the re!irement of final setting #imits:

Initial setting time sho!ld not *e less than 30 min for most of the cements e2cept >o( Beat cement at ,0 min and masonr% cement at 90 min Final setting time sho!ld not *e more than ,00 min for most of the cements !sed e2cept masonr% cement at 1440 min $iva %uestions and ans&ers '. (hat is unsound cement) #ist the components &hich cause unsoundness in cement

It is the cement material (hich (ill !ndergo change in &ol!me after setting ca!sing disr!ption of the set and hardened mass +resence of e2cess lime ma% *e one of the reasons Bigh proportion of magnesia Bigh amo!nt of g%ps!m addition *. (eather setting and hardening !oth are same   

Setting is descri*ed as the stiffness of cement paste it is the changes in cement paste from fl!id to rigid state. It occ!rs *efore hardening process starts Bardening refers to *e the gain of strength of set concrete. It occ!rs after setting 3. Factors affecting setting time of cement

1. @ater )ement ratio ". Temperat!re 3. )ement content 4. T%pe of )ement 5. Fineness of )ement ,. ?elati&e B!midit% /. dmi2t!res 8. T%pe and amo!nt of ggregate 9. +resence of mineral and chemical admi2t!res +. (hich t&o factors mainly influence setting time of cement

)3S and )3 i.e tri calci!m silicate and tri calci!m al!minate ,. Differentiate !et&een setting of PPC and PC. (hy it differs)

Setting time is more in case of ++) (hen compared (ith +). The setting time differed in  *oth *eca!se in ++) the time re!ired to form the gel (ill !s!all% *e more (hen compared (ith that of +)

-. (hat constituent of cement affects the early setting

Prepared by: Prof Hanamant Hunashika

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'%ps!m . (hat is the effect on setting time of cement if &ater added is less or more than /,0 of normal consistency of cement

If (ater added is more the setting time (ill increase and if the (ater added is less then the setting time (ill red!ce. /. (hich concreting &or1 depends on initial setting time of cement

+lacing

Prepared by: Prof Hanamant Hunashika

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