kankreet

vaanijyik bhavan ke liye kankreet bichhaayi ja rahi hai.

kankreet (Concrete) ek nirmaan saamagri hai jo cement evam kuchh anya padaarthon ka mishran hoti hai. kankreet ki yeh visheshata hai ki yeh paani milaakar chhod dene ke baad dheere-dheere thos evam kathor ban jaata hai. is prakriya ko jaleekaran (Hydration) kehte hai. is raasaayanik kriya mein paani, siment ke saath kriya karke patthar jaisa kathor padaarth banaati hai jismein anya cheejein bandh jaateen hain. kankreet ka prayog sadak banaane, pipe nirmaan, bhavan nirmaan, neenv banaane, pul aadi banaane mein hota hai.

kankreet ka upayog 2000 E.poo. se hota aa raha hai. kankreet ke gun un padaarthon par nirbhar hete hain jinse yeh banaaya jaata hai, paratu pradhaanat: ve us padaarth par nirbhar rahate hain jo patthar, gitti aadi ko paraspar chipkaane ke liye prayukt hota hai. 19veen shataabdi mein portalaind cement ke aavishkaar ke pale is kaam ke liye keval choona upalabdh tha, parantu ab choone ke kankreet ka upayog keval vaheen hota hai jahaaain adhik pushtata ki aavashyata nahi rahati. adhik pushtata ke liye simeint-kankreet ka upayaag hota hai. cement kankreet ko ispaat se drudh karke un sthaanon mein bhi prayukt kiya ja sakta hain jahaaain lapane ya mudane ki sambhaavana rahati hai, jaise dharanon athva stambhon mein.

anukram

sanrachana

kankreet agralikhit padaarthon ka mishran hai :

(1) koi akriyaasheel padaarth, jaise toota patthar ya int (gitti), badi bajari, chhaai (machine ki raakh, sindar) athva machine se nikla jhaavaaain;

(2) baaloo ya patthar ka choora ya pisi int (surakhi);

(3) poorvonkt padaarthon ke jodne ke liye kaai padaarth, jaise cement athva choona aur

(4) aavashyakataanusaar paani.

is mishran ko jab achhi tarah mila diya jaata hai aur keval itna dheela rakha jaata hai ki gaddhe ya saaainche ke kone-kone tak pahainch sake tab yeh kisi bhi aakruti ke gaddhe athva khokhale sthaan mein, jaise neenv ki athva meharaab ki bagal mein, bhara ja sakta hai.

cement kankreet

kankreet ka ek pul

yeh cement, paani, baaloo aur patthar ya int ki gitti athva badi bajari ya jhaavaaain se banta hai aur bhavananirmaan mein adhik kaam mein aata hai. jaisa oopar bataaya gaya hai, jab yeh padaarth bhali-bhaaainti mila diye jaate hain tab unase kumhaar ki mitti ki tarah plaistik padaarth banta hai, jo dheere-dheere patthar ki tarah kada ho jaata hai. yeh krutrim patthar prakruti mein milnevaale kaanglaamaret naamak patthar ke svabhaav ka hota hai. bhavananirmaan mein cement kankreet ke is gun ke karan yeh badi sugamata se kisi bhi sthaan mein dhaala ja sakta hai aur isko koi bhi vaanchhit roop diya ja sakta hai. iske liye aavashya padaarth praaya: sabhi sthaanon mein upalabdh rahate hain, parantu sarvottam parinaam ke liye kankreet ko milaane aur dhaalane ka kaam prashikshit majadooron ko saunpana chaahiye. kankreet ki pushtata uske avayavon ke anupaat aur unako milaane ke dhang par nirbhar rahati hai.

injeeniyri aur bhavananirmaan mein iske praaya: asankhya prakaar ke upayog ho sakte hain, jinmein bhaari neenve, pushte, nausthaan (daak, dock) ki bhittiyaaain, tarangon se raksha ke liye samudra mein bani deevaarein, pul, udrodh ityaadi bruhatkaaya sanrachanaaeain bhi sammilit hain. ispaat se prabalit (riinforsd, reinforced) kankreet ke roop mein yeh anek anya sanrachanaaon ke liye prayukt hota hai, jaise farsh, chhat, meharaab, paani ki tankiyaaain, attaalikaaeain, pul ke bade peepe (paantoon, pontoon), ghaat, naram bhoomi mein neenv ke neeche thoke jaanevo khooainte, jahaajon ke liye samudri ghaat, tatha anek anya rachanaaeain. tikaaoopan, pushtata, saundarya, agni ke prati sahanasheelata, sastaapan ityaadi aise gun hain jinke kaaran bhavananirmaan mein kankreet adhikaadhik lokapriya hota ja raha hai aur inke kaaran bhavananirmaan mein prayukt honevaale pehle ke kai anya padaarth hatate ja rahe hain.

gitti

baaloo patthar ya int ke chhote-chhote tukadon ko gitti kehte hain. gitti ke badle badi bajari aadi ka bhi upayog ho sakta hai, at: unako bhi ham yahaaain gitti ke antargat maaneinge. gitti aur baaloo donon ke sammilit roop ko abhismooh (aigriget) kehte hain. naap ke anusaar gitti ke nimnalikhit varg hain :

(k) daanavi (saaiklopiyn), jab naap 7.5 se 15 seinteemeetar tak (3 se 6 inch tak) hoti hai;

(kh) moti gitti, 0.5 se 7.5 seinteemeetar tak (3/16 se 3 inch tak);

(g) maheen, 0.15 se 5 mileemeetar tak (0.0059 se 3/16 inch tak).

gitti ki naap bataane ke liye "sookshmata maapaank" (faainanes maudyulas, Fineness modulus) ka prayog kiya jaata hai. naapane ke liye das praamaanik chalaniyaaain rahati hain jinki jaali ki naap nimnalikhit hoti hai :

3 inch, 1 inch, 0.5 inch, 0.3 inch, 2.41 mileemeetar, 1.204 mileemeetar, 0.599 mileemeetar, 0.152 mileemeetar. 2.41 mileemeetaravaali chalni ko number 7 chalni tatha uske baad ki chalaniyon ka kramaanusaar number 14, number 25 number 52 aur number 100 bhi kehte hain.

sookshmata maapaank praapt karne ke liye maal ko in chalaniyon se kramaanusaar chala jaata hai. maal ki taul ke anusaar in chalaniyon par jitna pratishat bacha rah jaata hai unke yogafal ko 100 se bhaag de diya jaata hai. is prakaar praapt labdhi ko sookshmata maapaank kehte hain.

kankreet ke liye sookshm milaave (baaloo ya surkhi) ka sookshmata maapaank 2 aur 3 ke beech hona chaahiye aur mote milaave (gitti) ka 5 aur 8 ke beech.

sookshm milaave (baaloo ityaadi) ka 90 pratishat ansh inch ki jaali ke paar ho jaana chaahiye aur 100 nanbaravaali jaali par 85 pratishat se kam naheen pada rahana chaahiye (arthaat baaloo mein dhooli aadi bahut na ho.). sookshm milaave ke liye nadi ya samudra ki baaloo, athva patthar ki Khan se nikla choora peesakar prayukt kiya jaata hai. praakrutik athva pisi bajari mein mitti, talachhat aur dhooli taul ke anusaar 3 pratishat se adhik naheen honi chaahiye tatha choorn kiye gaye patthar mein 10 pratishat se adhik dhooli aadi na honi chaahiye. baaloo aadi ko ghaas paat aadi praanij (ogainnik, organic) ashuddhiyon se mukt hona chaahiye.

mote milaave (gitti) ke kam se kam 95 pratishat ko 3 inchavaali chalni se paar ho jaana chaahiye aur kam se kam 90 pratishat ko inchavaali chalni par pada rahana chaahiye. toda gaya patthar, todi gayi int, choor kiya gaya patthar, jhaavaaain athva chhaai, ye sab mote milaave ke liye kaam mein laai ja sakti hai. chhaai aur kok halake kankreet ke liye upayogi hain, parantu bhaari aur pusht kaam ke liye choone ka patthar, grainaait, naais, trap athva kada baluaa patthar kaam mein laaya jaata hai. chipkaanevaale padaarth (cement) se kamjor padnevaale naram patthar ka prayog karna chaahiye.

gitti kuchh golaakaar ho, ruksh ho, usase chippad na chhootein aur todne mein pusht ho. taul ke anusaar gitti paaainch pratishat se adhik paani sokhe. usamein yathaasanbhav mitti na ho aur praanij (ogainnik) padaarth (jaise ghaas, kaai ityaadi) na hon.

cement

yon to kaarya aur aavashyakta ke anusaar kai prakaar ke seemeinton ka vyavahaar kiya jaata hai, parantu saadhaaran kaam ke liye adhiktar portalaind cement kaam mein laaya jaata hai. yeh pradhaanat: traaikailsiym siliket, daaikailsiym siliket, traaikailsiym ailyuminet aur jipsam ka mishran hota hai. paani milaane ke baad sabse pehle pushtata ailyumineton aur traaikailsiym siliket se aati hai, kyonki paani ka shoshan karte samay unke kaaran adhik garami utpann hoti hai. kaam mein laane ke pehle cement ko sookhe sthaan mein rakhana chaahiye anyatha aardrata se cement kharaab ho jaaega. nam sthaan mein rakhane se jo cement kada ho jaata hai vah kisi kaam ka naheen rahata. kabhi-kabhi, jab cement ki boriyaaain ek ke oopar ek bahut ooainchaai tak ladi rahati hain tab neeche ka cement adhik daab ke kaaran bhi baindh jaata hai, parantu yeh cement kharaab naheen rahata aur kankreet banaate samay saralataapoorvak anya padaarthon ke saath mil jaata hai.

kada hone ka praarambhik samay 30 minute se kam naheen hona chaahiye. kankreet ko saanane ke baad 30 minute ke bheetar hi apne sthaan mein dhaal dena chaahiye. kada hone ka antim samay 10 ghante se kam na hona chaahiye. saat din ke baad pareeksha lene par daab aur tanaav mein cement ki pushtata kramaanusaar 2.500 pound prati varg inch aur 375 pound prati varg inch se kam na honi chaahiye. 170 number ki chalni se cement ke 90 se adhik ansh ko paar ho jaana chaahiye aur ek gram cement ke kanon ka sammilit kshetrafal 2,250 varg seinteemeetar se kam na hona chaahiye.

paani

paani svachh ho, usamein praanij padaarth, aml, kshaar aur koi bhi anya haanikaarak padaarth na hona chaahiye. sankshep mein, jo jal peene yogya hota hai vahi kankreet banaane ke bhi yogya hota hai.

padaarthon ki naap

kankreet banaane mein vividh padaarthon ko theek-theek naapana bahut mahatvapoorn hai. jab padaarthon ko aayatan ke anusaar naapakar milaaya jaata hai tab naapanevaala bartan chhota bada hone se antim naap mein antar pad jaata hai, iska prabhaav bhi antim naap par padta hai. fir, milaave ki kism aur usaki aardrata ka bhi prabhaav padta hai. maheen milaave (baaloo aadi) mein 3.5 pratishat aardrata rahane par aayatan lagbhag 25 pratishat adhik ho jaata hai. milaava jitna hi adhik maheen hoga, aardata se aayatan utana hi adhik badhega.

at: achhe kaam mein padaarthon ko taulakar milaana chaahiye. parantu saadhaaranat: nirmaan kaaryon mein padaarthon ki naap aayatan se hoti hai. at: un sabhi baaton par dhyaan rakhana atyant aavashyak hai jinse aayatan ghatata badhta hai. cement ki pratyek bori ke liye aavashyak paani ki maatra saadhaaranat: gailanon mein bataai jaati hai.

sukarata (barkebilti, workability) ka anumaan is baat se kiya jaata hai ki kankreet ke milaane, dhaalane aur dhaalane ke baad kootane mein kitna samay lagta hai. sukarata jal ki maatra, gitti ki naap aur mote tatha maheen milaave ke anupaat par nirbhar rahati hai. jal aur maheen milaava badhaane se sukarata badhti hai. sukarata naapane ki kai reetiyaaain hain parantu adhik upayog avapaat (slanp, slump) reeti ka hi hota hai. is reeti ka varnan neeche kiya jaata hai.

taaja bane kankreet ko peindi rahit baalti mein daalte hain jiski aakruti shanku ke chhinnak (fstam) ki bhaaainti hoti hai. oopar ka vyaas 5 inch tatha neeche ka 8 inch hota hai aur ooainchaai 12 inch hoti hai. kankreet ko is bartan mein bharakar kootane ke baad, baratan ko utha liya jaata hai. tab kankreet kuchh baith jaata hai. kankreet ka maatha jitne neeche dhainsata hai utana hi avapaat (slanp) kahalaata hai. avapaat jitna hi adhik hoga, sukarata bhi utani hi adhik hogi. sadak banaane ke liye 1 inch ke kankreet ka avapaat theek rahata hai. chhat, dharan (beam, beam) ityaadi mein avapaat 1h inch se 2 inch tak hona chaahiye. khanbhon aur un patali deevaaron ke liye jo kamron ko do ya adhik khandon mein baaaintane ke liye khadi ki jaati hain, avapaat ko 4 inch tak badhaana padta hai, jismein kankreet failakar sab jagah pahuainch jaae aur kaheen polaapan na rah jaae.

kankreet ki pushtata (streinth, strength), cement ke gun, jal aur cement ke anupaat aur saghanata ki maatra par nirbhar hoti hai. yadi cement vahi rahe aur gitti tatha baaloo is prakaar se vividh naapon ke rahein ki poorn saghanata praapt ho to kankreet ki pushtata jal aur cement ke anupaat par nirbhar rahegi. jal aur cement ka anupaat badhne se, arthaat adhik jal milaane se, pushtata ghatati hai, parantu smaran rahe ki paani ki maatra ek nishchit seema se kam naheen ki ja sakti. raasaayanik kriya poori hone ke liye jal ki maatra cement ki maatra ki kam se kam 0.25 honi chaahiye, parantu sukarata ke liye aur kankreet ko kootakar saghan bana sakane ke liye isse adhik paani ki aavashyakta padti hai.

0.35 se kam anupaat mein paani milaakar banaaya gaya mishran praaya: itna kharra (sookha) hota hai ki isse kaam naheen liya ja sakta.

kankreet ka tikaaoopan pradhaanat: usaki saghanata par nirbhar rahata hai. kankreet mein jitne hi kam randhr rahate hain, usamein utana hi kam kshaareeya jal athva anya haanikr padaarth ghul paate hain, isliye usamein utana hi kam kshaya hota hai. saghanata praapt karne ke liye yathaasanbhav kam paani daalna chaahiye aur gitti ke rodon ki naap tatha baaloo ka prakaar aur usaki maatra aisi honi chaahiye ki kankreet mein rikt sthaan na chhootane paae.

mitvyayata ya sastepan ke liye yeh aavashyak hai ki cement kam se kam pade aur milaane, dhaalare tatha kootane mein parishram nyoonatam lage. etadarth iska dhyaan rakhana chaahiye ki aavashyak sukarata ke liye jitna nyoonatam jal apekshit ho usase adhik na chhoda jaae.

in sab baaton par vichaar karne se spasht hai ki hamein pehle aisa jal-cement-anupaat chunana chaahiye ki aavashyak pushtata mile aur tab maheen aur mote milaave ke avayavon ka is anupaat mein rakhana chaahiye ki achhi sukarata aur poorn saghanata ke liye usamein nyoonatam maatra mein jal aur cement ka mishran daalna pade. poorn saghanata ka arth yeh hai ki milaave (gitti baaloo) ke kanon ke beech ke samast rikt sthaan jal-cement-mishran se bhar uthein aur vaayu ke bulabule kaheen na rahein.

milaave ke vividh padaarthon ko naap ke anusaar uchit anupaat mein milaana atyant mahatvapoorn hai. isse keval pushtata hi naheen badhti, sukarata bhi badhti hai. uchit reeti se shreneebaddh gitti-baaloo mein sabhi naapon ke kan is prakaar rahate hain ki bade kanon ke beech ke rikt sthaan chhote kanon se bhar jaate hain, ityaadi. yadi aisaan hua to sab rikt sthaanon ko jal-cement-mishran se bharna padega. isliye kankreet ki charam saghanata ke nimitt milnevaale milaave ki gitti aur baaloo ko is prakaar uchit reeti se shreneebaddh kiya jaata hai ki milaave mein kam se kam riktata ho jaae. kuchh mahatvapoorn kaamon mein sastepan ke liye antar-shreneekaran (gaip greding) ki reeti barati jaati hai. ismein british standard number se 7 ki chalni tak ki bajari ko milaave mein sammilit naheen kiya jaata hai.

aavashyak maatraaon ka anupaat

saadhaaranat: kankreet ka mishran cement, baaloo aur gitti ke aayatanon ke anupaat ke anusaar taiyaar kiya jaata hai. kabhi-kabhi cement ki maatra bataane ke liye boriyon ki sankhya bataai jaati hai. pratyek bori mein 112 pound ya 1.25 ghan foot cement rahata hai. is prakaar 1 : 2 : 4 ke kankreet mishran ka arth hai 1 ghan foot cement (jiski taul prati ghanafut 90 pound hoti hai), 2 ghanafut baaloo (athva anya maheen milaava) aur 4 ghan foot gitti. mishran mein ausat se 66% se 78% milaava 7% se 14% cement aur 15% se 22% paani hota hai. is prakaar 100 ghan foot taiyaar (saghan kiye gaye) kankreet ke liye kuchh milaakar lagbhag 155 ghan foot sookhein padaarth ki aavashyakta padti hai.

kankreet ka milaana

yeh mahatvapoorn hai ki sab padaarth achhi tarah mil jaaeain jismein sarvatr ek samaan ki sanrachana rahe. jab kabhi adhik kankreet ki aavashyakta hoti hai tab use haath se milaana kathin hota hai isliye machine ka prayog kiya jaata hai. aisi machine mein ek bada sa dhol rahata hai jiske bheetar pankhe lage rahate hain. dhol ko engine se ghumaaya jaata hai aur bheetar cement, baaloo, gitti aur paani naapakar daal diya jaata hai. sheegra hi achha mishran taiyaar ho jaata hai.

kankreet ko dhaalana aur kootana

mishran taiyaar hone ke baad kankreet ko chapapat dhaalana aur saghan karna chaahiye. paani daalne ke kshan se is kriya ke ant tak kul 30 minute se kam samay lagana chaahiye. ispar bhi iska dhyaan rakhana chaahiye ki dhaalate samay kankreet ke mishran ka koi avayav anshat: alag na hone paae. iska taatparya yeh hai ki kankreet bahut ooainche se naheen giraaya jaana chaahiye.

kankreet ki kutaai lohe ke chhadon se karni chaahiye aur is prakriya mein chhadon ko kuchh door tak kankreet mein ghus jaana chaahiye. jab mishran itna sookha rahata hai ki is vidhi ka prayog naheen kiya ja sakta to kanpanakaari yantron ka prayog kiya jaata hai jismein poori saghanata aa sake. sapaat (chauras) satahon ke liye aise kanpanakaariyon ka prayog kiya jaata hai jo satah ke oopar rakhe jaate hain, parantu dharanon aur deevaaron ke liye kankreet ke bheetar daale jaanevaale kanpanakaariyon se kaam liya jaata hai. kintu yadi kankreet ke bheetar kanpanakaari ko daalne ki suvidha bhi na ho to aise baahari kanpanakaariyon ka upayog kiya jaata hai jo saaainche ko hilaate hain aur is prakaar kankreet saghan ho jaata hai.

kam kutaai to haanikaarak hai hi, parantu kutaai ya kanpan ki adhikta bhi haanikr ho sakti hai, kyonki isse kankreet ke avayav alag hone lagte hain aur usamein madhumakkhi ke chhatte ki tarah rikt sthaan ban jaane ki sambhaavana rahati hai. at: yeh chetaavani dena uchit hai ki poorn saghanata ke badle keval 85 pratishat saghanata utpann ki jaae to pushtata poorn saghan kankreet ki kul 15 pratishat hi utpann hogi.

kankreet ko paripakva karna

jab tak kankreet kada hota rahata hai tab tak use aardr rakhana chaahiye. is kriya ko paripkveekaran (pakka karna) kehte hain. yeh atyant mahatvapoorn hai ki kada hone ki kriya mein jitna paani cement ke raasaayanik sanyog ke liye aavashyak hai, utana use milta rahe. yadi kankreet ko theek prakaar se paripakva na kiya jaae to pushtata bahut kam ho jaati hai. kankreet ki pushtata ka adhikaansh do teen saptaahon mein utpann hota hai, ataev itne hi samay tak ko aardr rakhana aavashyak hai. yadi is samay mein kankreet sookhe vaataavaran mein rahata hai to usamein adhik sankoch ho jaata hai aur parinaamat: vah fat jaata hai.

yadi taap adhik ho to kankreet ki pushtata kam samay mein aati hai. isliye jaade ki apeksha garami ke dinon mein saaaincha kam samay mein hataaya ja sakta hai. yadi kankreet ko bahut sheegra paripakva karna rahata hai to kankreet ko bhaap se tapt kiya jaata hai. bahudha sadak banaane mein aisa karna padta hai, kyonki sadkon ke do teen saptaah tak band rakhane mein asuvidha hoti hai.

kankreet ke gun

nimnalikhit saarani mein vividh sanrachanaaon ke kankreet aur unke gun dikhaae gaye hain :

28 din baad sanpeedan kshamata, mishran pound prati varg inch, prayog

1 : 2 : 4 2,250 prabalit (riinforsd) kaam mein.

1 : 1 : 3 2,850 meharaab, stambh, paani ki tankiyon aur paani ke anya kaamon mein.

1 : 1 : 2 3,450 poorv pratiblit (prastresd,) kankreet aur aisi sanrachanaaon mein jahaaain vishesh pushtata ki aavashyakta hoti hai.

saada kankreet

jo kankreet prabalit (riinforsd) naheen rahata use saada (plane) kankreet kehte hain. saadhaaran bojhavaali deevaaron ki neevon mein saadhaaranat: 1 : 3 : 6 ka cement kankreet diya jaata hai. yadi bhoomi kadi ho to khanbhon ki neevon mein bhi aisa hi kankreet diya ja sakta hai. tanaav mein aisa kankreet bahut pusht naheen hota aur jab kisi bhaag mein tanaav padne ki aashanka rahati hai tab use ispaat ki chhadon se prabalit karna aavashyak hota hai.

vipul kankreet

jab bahut bade aayatanavaala, kankreet ka koi kaam banta hai, jaise udrodh (daim), pushta (ritening vaal), bhaari kaam honevaale kaarkhaane ka farsh, ityaadi tab subheete ke liye use vipul kankreet (maas kankreet) kaha jaata hai. jab kabhi bahut sa kankreet ek saath dhaala jaata hai tab cement ke jal sokhane se badi garami utpan hoti hai. peechhe jab kankreet thanda hota tab bheetari tanaav bahut ho jaata hai aur kankreet chatakh jaata hai. isliye udrodh aadi banaane mein gitti aur baaloo ko pehle se khoob thanda kar liya jaata hai aur kankreet mein nal (pipe) laga diye jaate hain, jinmein thanda paani pravaahit kiya jaata hai. isse taap badhne naheen paata. vipul kankreet ke liye badi naap ki gittiyon ka upayog kiya jaata hai jo vyaas mein 6 inch tak ki hoti hain. isse paani kam kharch hota hai aur yadi jal-cement-anupaat na badla jaae to cement bhi kam kharch hota hai. falat: bachat hoti hai. saath hi, kankreet ka ghanatv bhi badh jaata hai. yeh gurutvaudrodh aur badi tankiyon ke farsh ke liye mahatvapoorn hota hai, kyonki ye apni sthirta ke liye apne hi bhaar par nirbhar rahate hain.

baahari kadiyaaain